9584080 Steam Systems Design Pipes and Valves

DESIGNOF FLUID

SYSTEMS

HO

OK

-U

PS

Published by

$19.95 per copy

First Printing January, 1968Second Edition – First Printing October, 1968

Third Edition – First Printing May, 1970Fourth Edition – First Printing September, 1974

Fifth Edition – First Printing August, 1975Sixth Edition – First Printing May, 1978

Seventh Edition – First Printing September, 1981Eighth Edition – First Printing January, 1987Ninth Edition – First Printing April, 1990Tenth Edition – First Printing January, 1991

Eleventh Edition – First Printing April, 1997Twelfth Edition – First Printing June, 2000

Second Printing June, 2001

Copyright © 2004by Spirax Sarco, Inc.

All Rights ReservedNo part of this publication may be reproduced, stored in a

retrieval system or transmitted, in any form or by any means,electronic, mechanical, photocopying, recording, or otherwise,

without the prior written permission of the publisher.

Spirax Sarco, Inc.1150 Northpoint Blvd. Blythewood, SC 29016

Phone: (803) 714-2000Fax: (803) 714-2222

www.spiraxsarco.com/us

II

Spirax Sarco

III

Spirax Sarco is the recognized industry standard forknowledge and products and for over 85 years hasbeen committed to servicing the steam users world-wide. The existing and potential applications for steam,water and air are virtually unlimited. Beginning withsteam generation, through distribution and utilizationand ultimately returning condensate to the boiler,Spirax Sarco has the solutions to optimize steam sys-tem performance and increase productivity to savevaluable time and money.

In today’s economy, corporations are looking for reli-able products and services to expedite processes andalleviate workers of problems which may arise withtheir steam systems. As support to industries aroundthe globe, Spirax Sarco offers decades of experience,knowledge, and expert advice to steam users world-wide on the proper control and conditioning of steamsystems.

Spirax Sarco draws upon its worldwide resources ofover 3500 people to bring complete and thorough ser-vice to steam users. This service is built into ourproducts as a performance guarantee. From initial con-sultation to effective solutions, our goal is tomanufacture safe, reliable products that improve pro-ductivity. With a quick, responsive team of salesengineers and a dedicated network of local authorizeddistributors Spirax Sarco provides quality service andsupport with fast, efficient delivery.

Reliable steam system components are at the heart ofSpirax Sarco’s commitment. Controls and regulatorsfor ideal temperature, pressure and flow control; steamtraps for efficient drainage of condensate for maximumheat transfer; flowmeters for precise measurement ofliquids; liquid drain traps for automatic and continuousdrain trap operation to boost system efficiency; rotaryfilters for increased productivity through proper filteringof fluids; condensate recovery pumps for effective con-densate management to save water and sewage costs;stainless steel specialty products for maintaining qual-ity and purity of steam; and a full range of pipelineauxiliaries, all work together to produce a productivesteam system. Spirax Sarco’s new line of engineeredequipment reduces installation costs with prefabricatedassemblies and fabricated modules for system integri-ty and turnkey advantages.

From large oil refineries and chemical plants to locallaundries, from horticulture to shipping, for hospitals,universities, offices and hotels, in business and gov-ernment, wherever steam, hot water and compressedair is generated and handled effectively and efficiently,Spirax Sarco is there with knowledge and experience.

For assistance with the installation or operation of anySpirax Sarco product or application, call toll free:

1-800-883-4411

How to Use This Book

IV

Selection of the most appropriate type and size ofcontrol valves, steam traps and other fluid controlvalves, steam traps and other fluid control equip-ment, and installation in a hook up enabling thesecomponents of a system to operate in an optimalmanner, all bear directly on the efficiency and econ-omy obtainable in any plant or system.

To help make the best choice, we have assembledinto this book the accumulation of over 85 years ofexperience with energy services in industrial andcommercial use. The hook ups illustrated have allbeen proven in practice, and the reference informa-tion included is that which we use ourselves whenassisting customers choose and use our products.

The Case in Action stories dispersed throughout thisbook are actual applications put to the test by steamusers throughout the country. Their stories are testi-monials to the products and services Spirax Sarcooffers and the benefits they have received from uti-lizing our knowledge and services.

The Hook Up Book is divided into three sections:

Section I is a compilation of engineering data andinformation to assist in estimating loads and flowrates, the basic parameters which enable the bestchoice when selecting sizes.

Section II illustrates how the services and controlequipment can be assembled into hook ups tobest meet the particular needs of each application.

Section III is a summary of the range of SpiraxSarco equipment utilized in the hook ups. Althoughit is not a complete catalog of the entire range, itdoes describe generically the capabilities and limi-tations which must be remembered when makingproper product choices.

Most application problems will be approached in thesame order. Section I will enable the load informa-tion to be collected and the calculations made sothat sizing can be carried out; Section II will makesure that the essentials of the hook up, or combina-tion of hook ups, are not overlooked; and Section IIIwill serve as a guide to the complete equipment cat-alog so that the most suitable equipment can readilybe selected.

The Hook Up Book is intended to serve as a refer-ence for those actively engaged in the design,operation and maintenance of steam, air and liquidsystems. It is also intended as a learning tool toteach engineers how to design productive steamsystems, efficiently and cost effectively.

We gratefully acknowledge the valuable contribu-tions made by our field engineers, representatives,application engineers, and customers to the bodyof accumulated experience contained in this text.

V

Section 1: System Design Information .........................................................1

The Working Pressure in the Boiler and the Mains ............................................................2Sizing Steam Lines on Velocity...........................................................................................3Steam Pipe Sizing for Pressure Drop.................................................................................5Sizing Superheated Mains..................................................................................................6Properties of Saturated Steam ...........................................................................................7Draining Steam Mains ........................................................................................................8Steam Tracing ...................................................................................................................12Pressure Reducing Stations .............................................................................................19Parallel and Series Operation of Reducing Valves ...........................................................21How to Size Temperature and Pressure Control Valves ...................................................23Temperature Control Valves for Steam Service ................................................................26Temperature Control Valves for Liquid Service.................................................................28Makeup Air Heating Coils .................................................................................................31Draining Temperature Controlled Steam Equipment ........................................................33Multi-Coil Heaters .............................................................................................................36Steam Trap Selection........................................................................................................38Flash Steam......................................................................................................................41Condensate Recovery Systems .......................................................................................45Condensate Pumping .......................................................................................................48Clean Steam .....................................................................................................................50Testing Steam Traps..........................................................................................................55Spira-tec Trap Leak Detector Systems for Checking Steam Traps ...................................58Steam Meters....................................................................................................................59Compressed Air Systems .................................................................................................62Reference Charts and Tables ...........................................................................................66

Section 2: Hook-up Application Diagrams................................................83

For Diagram Content, please refer to Subject Index on page 149.

Section 3: Product Information .....................................................................143

An overview of the Spirax Sarco Product Line

Subject Index ...................................................................................149

Table of Contents

VI

SYSTEMDESIGN

INFORMATION

Section 1

The Working Pressure in the Boiler and the Mains

2

Steam should be generated at apressure as close as possible tothat at which the boiler isdesigned to run, even if this ishigher than is needed in theplant. The reasoning behind thisis clear when consideration isgiven to what happens in thewater and steam space within theboiler. Energy flows into the boilerwater through the outer surface ofthe tubes, and if the water isalready at saturation tempera-ture, bubbles of steam areproduced. These bubbles thenrise to the surface and break, torelease steam into the steamspace.

The volume of a given weightof steam contained in the bubblesdepends directly on the pressureat which the boiler is operating. Ifthis pressure is lower than the

design pressure, the volume inthe bubbles is greater. It followsthat as this volume increases, theapparent water level is raised.The volume of the steam spaceabove the water level is therebyreduced. There is increased tur-bulence as the greater volume ofbubbles break the surface, andless room for separation of waterdroplets above the surface.Further, the steam movingtowards the crown or steam take-off valve must move at greatervelocity with a higher volumemoving across a smaller space.All these factors tend to encour-age carryover of water dropletswith the steam.

There is much to be said infavor of carrying the steam closeto the points of use at a high pres-sure, near to that of the boiler.

The use of such pressure meansthat the size of the distributionmains is reduced. The smallermains have smaller heat losses,and better quality steam at thesteam users is likely to result.

Pressure reduction to the val-ues needed by the steam usingequipment can then take placethrough pressure reducing sta-tions close to the steam usersthemselves. The individual reduc-ing valves will be smaller in size,will tend to give tighter control ofreduced pressures, and emit lessnoise. Problems of having awhole plant dependent on a sin-gle reducing station are avoided,and the effects on the steamusers of pressure drops throughthe pipework, which change withvarying loads, disappear.

SYSTEMDESIGN

Table 1: Steam Pipe Sizing for Steam Velocity Capacity of Sch. 80 Pipe in lb/hr steam

Pressure Velocitypsi ft/sec 1/2" 3/4" 1" 11/4" 11/2" 2" 21/2" 3" 4" 5" 6" 8" 10" 12"

50 12 26 45 70 100 190 280 410 760 1250 1770 3100 5000 71005 80 19 45 75 115 170 300 490 710 1250 1800 2700 5200 7600 11000

120 29 60 110 175 245 460 700 1000 1800 2900 4000 7500 12000 1650050 15 35 55 88 130 240 365 550 950 1500 2200 3770 6160 8500

10 80 24 52 95 150 210 380 600 900 1500 2400 3300 5900 9700 13000120 35 72 135 210 330 590 850 1250 2200 3400 4800 9000 14400 2050050 21 47 82 123 185 320 520 740 1340 1980 2900 5300 8000 11500

20 80 32 70 120 190 260 520 810 1100 1900 3100 4500 8400 13200 18300120 50 105 190 300 440 840 1250 1720 3100 4850 6750 13000 19800 2800050 26 56 100 160 230 420 650 950 1650 2600 3650 6500 10500 14500

30 80 42 94 155 250 360 655 950 1460 2700 3900 5600 10700 16500 23500120 62 130 240 370 570 990 1550 2100 3950 6100 8700 16000 25000 3500050 32 75 120 190 260 505 790 1100 1900 3100 4200 8200 12800 18000

40 80 51 110 195 300 445 840 1250 1800 3120 4900 6800 13400 20300 28300120 75 160 290 460 660 1100 1900 2700 4700 7500 11000 19400 30500 4250050 43 95 160 250 360 650 1000 1470 2700 3900 5700 10700 16500 24000

60 80 65 140 250 400 600 1000 1650 2400 4400 6500 9400 17500 27200 38500120 102 240 410 610 950 1660 2600 3800 6500 10300 14700 26400 41000 5800050 53 120 215 315 460 870 1300 1900 3200 5200 7000 13700 21200 29500

80 80 85 190 320 500 730 1300 2100 3000 5000 8400 12200 21000 33800 47500120 130 290 500 750 1100 1900 3000 4200 7800 12000 17500 30600 51600 7170050 63 130 240 360 570 980 1550 2100 4000 6100 8800 16300 26500 35500

100 80 102 240 400 610 950 1660 2550 3700 6400 10200 14600 26000 41000 57300120 150 350 600 900 1370 2400 3700 5000 9100 15000 21600 38000 61500 8630050 74 160 290 440 660 1100 1850 2600 4600 7000 10500 18600 29200 41000

120 80 120 270 450 710 1030 1800 2800 4150 7200 11600 16500 29200 48000 73800120 175 400 680 1060 1520 2850 4300 6500 10700 17500 26000 44300 70200 9770050 90 208 340 550 820 1380 2230 3220 5500 8800 12900 22000 35600 50000

150 80 145 320 570 900 1250 2200 3400 4900 8500 14000 20000 35500 57500 79800120 215 450 850 1280 1890 3400 5300 7500 13400 20600 30000 55500 85500 12000050 110 265 450 680 1020 1780 2800 4120 7100 11500 16300 28500 45300 64000

200 80 180 410 700 1100 1560 2910 4400 6600 11000 18000 26600 46000 72300 100000120 250 600 1100 1630 2400 4350 6800 9400 16900 25900 37000 70600 109000 152000

Sizing Steam Lines On Velocity

3

The appropriate size of pipe tocarry the required amount ofsteam at the local pressure mustbe chosen, since an undersizedpipe means high pressure dropsand velocities, noise and erosion,while a generously sized pipe isunnecessarily expensive to installand heat losses from it will alsobe greater than they need be.

Steam pipes may be sizedeither so that the pressure dropalong them is below an accept-able limit, or so that velocitiesalong them are not too high. It isconvenient and quick to sizeshort mains and branches onvelocity, but longer runs of pipeshould also be checked to seethat pressure drops are not toohigh.

Steam Line VelocitiesIn saturated steam lines, reason-able maximum for velocities areoften taken at 80/120 ft. per sec-ond or 4800/7200 fpm. In thepast, many process plants haveused higher velocities up to 200ft. per second or 12,000 fpm, onthe basis that the increased pipenoise is not a problem within aprocess plant. This ignores theother problems which accompanyhigh velocities, and especially theerosion of the pipework and fit-tings by water droplets moving athigh speed. Only where apprecia-ble superheat is present, with thepipes carrying only a dry gas,should the velocities mentionedbe exceeded. Velocity of saturat-ed steam in any pipe may beobtained from either Table 1, Fig.1 or calculated in ft. per minuteusing the formula:

Formula For Velocity OfSteam In Pipes

V = 2.4Q VsA

Where:V - Velocity in feet per minuteQ - Flow lbs./hr. steamVs - Sp. Vol. in cu. ft./lb. at the

flowing pressureA - Internal area of the pipe—

sq. in.

Steam Piping For PRV’s andFlash VentsVelocity in piping other thansteam distribution lines must becorrectly chosen, including pres-sure reducing valve and flashsteam vent applications.

A look at Steam Properties(Table 3) illustrates how the spe-cific volume of steam increasesas pressure is reduced. To keepreducing valve high and low pres-sure pipe velocity constant, thedownstream piping cross-section-al area must be larger by thesame ratio as the change in vol-ume. When downstream pipe sizeis not increased, low pressuresteam velocity increases propor-tionally. For best PRV operation,without excessive noise, longstraight pipe runs must be provid-ed on both sides, with pipingreduced to the valve thenexpanded downstream graduallyto limit approach and exit steamvelocities to 4000/ 6000 fpm. Asizing example is given in Fig. 1.

Line velocity is also important

in discharge piping from steamtraps where two-phase steam/condensate mixtures must beslowed to allow some gravity sep-aration and reduce carryover ofcondensate from flash vent lines.Here line velocities of the flashsteam should not exceed 50/66 ft.per second. A much lower veloci-ty must be provided forseparation inside the flash vesselby expanding its size. The flashload is the total released by hotcondensate from all traps drain-ing into the receiver. Forcondensate line sizing example,see page 46 and see page 43 forvent line sizing example.

SYSTEMDESIGN

Sizing Steam Lines On Velocity

4

Fig. 1 lists steam capacities ofpipes under various pressure andvelocity conditions.EXAMPLE: Given a steam heat-ing system with a 100 psig inletpressure ahead of the pressurereducing valve and a capacity of1,000 pounds of steam per hourat 25 psig, find the smallest sizesof upstream and downstream pip-ing for reasonable quiet steamvelocities.

Upstream Piping SizingEnter the velocity chart at A for1,000 pounds per hour. Go overto point B where the 100 psigdiagonal line intersects. Follow upvertically to C where an inter-section with a diagonal line fallsinside the 4,000-6,000 foot-per-minute velocity band. Actualvelocity at D is about 4,800 feetper minute for 1-1/2 inchupstream piping.

Downstream Piping SizingEnter the velocity chart at A for1,000 pounds per hour. Go overto point E where the 25 psig diag-onal line intersects. Follow upvertically to F where an intersec-tion with a diagonal line fallsinside the 4,000-6,000 foot-per-minute velocity band. Actualvelocity at G is 5,500 feet perminute for 2-1/2 inch downstreampiping.

Pressure Drop in Steam LinesAlways check that pressure dropis within allowable limits beforeselecting pipe size in long steammains and whenever it is critical.Fig. 2 and Fig. 3 provide drops inSch. 40 and Sch. 80 pipe. Use ofthe charts is illustrated in the twoexamples.

EXAMPLE 1What will be the smallest sched-ule 40 pipe that can be used ifdrop per 100 feet shall notexceed 3 psi when flow rate is10,000 pounds per hour, andsteam pressure is 60 psig?Solution:1. Find factor for steam pres-

sure in main, in this case 60psig. Factor from chart = 1.5.

2. Divide allowable pressuredrop by factor 3 .–. 1.5 = 2 psi.

3. Enter pressure drop chart at2 psi and proceed horizontal-ly to flow rate of 10,000pounds per hour. Select pipesize on or to the right of thispoint. In this case a 4" main.

EXAMPLE 2What will be the pressure dropper 100 feet in an 8" schedule 40steam main when flow is 20,000pounds per hour, and steampressure is 15 psig?

Solution:Enter schedule 40 chart at20,000 pounds per hour, proceedvertically upward to 8" pipe curve,then horizontally to pressure dropscale, read 0.23 psi per 100 feet.This would be the drop if thesteam pressure were 100 psig.Since pressure is 15 psig, a cor-rection factor must be used.Correction factor for 15 psig = 3.60.23 x 3.6 = 0.828 psi drop per100 feet for 15 psig

SYSTEMDESIGN

Figure 1: Steam Velocity Chart

Steam Pipe Sizing For Pressure Drop

5

SYSTEMDESIGN

Figure 2: Pressure Drop in Schedule 40 Pipe

Figure 3: Pressure Drop in Schedule 80 Pipe

100 300200 400 500 1,000 2 3 4 5 10,000 2 3 4 5 6 7 8 100,000 2 3 4 5 1,000,000 2.1

.2

.3

.4

.5

.6

.7

.8

.91.0

2.0

3.0

4.05.06.07.08.09.0

10.0

15.03/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 5" 6" 8" 20"10" 12" 14" 16" 18"

24"

psi 0 2 5 10 15 20 30 40 60 75 90 100 110 125 150 175 200 225 250 300factor 6.9 6.0 5.2 4.3 3.6 3.1 2.4 2.0 1.5 1.3 1.1 1.0 0.92 0.83 0.70 0.62 0.55 0.49 0.45 0.38

350 400 500 6000.33 0.29 0.23 0.19

Steam Flow lbs/hr

100 psig Saturated SteamFor other pressures use correction factors

Pre

ssu

re D

rop

psi

/100

ft

psi 0 2 5 10 15 20 30 40 60 75 90 100 110 125 150 175 200 225 250 300factor 6.9 6.0 5.2 4.3 3.6 3.1 2.4 2.0 1.5 1.3 1.1 1.0 0.92 0.83 0.70 0.62 0.55 0.49 0.45 0.38

350 400 500 6000.33 0.29 0.23 0.19

Steam Flow lbs/hr

100 psig Saturated SteamFor other pressures use correction factors

Pre

ssu

re D

rop

psi

/100

ft

100 300200 400 500 1,000 2 3 4 5 10,000 2 3 4 5 6 7 8100,000 2 3 4 5 1,000,000 2.1

.2

.3

.4

.5

.6

.7

.8

.91.0

2.0

3.0

4.05.06.07.08.09.0

10.0

15.03/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 5" 6" 8" 20"10" 12" 14" 16" 18" 24"

6

Sizing Superheated Mains

6

Sizing Superheated MainsWhen sizing steam mains forsuperheated service, the follow-ing procedure should be used.Divide the required flow rate bythe factor in Table 2. This will givean equivalent saturated steamflow. Enter Fig. 1, Steam VelocityChart on page 4 to select appro-priate pipe size. If unable, thenuse the formula on page 3 to cal-culate cross sectional area of thepipe and then Tables 38 and 39,page 81, to select the pipe sizewhich closely matches calculatedinternal transverse area.

Example:Size a steam main to carry34,000 lb/h of 300 psig steam at atemperature of 500° F.From Table 2 the correction factoris .96. The equivalent capacity is34,000

.96 = 35,417 lb/h.

Since 300 psig is not found onFig. 1, the pipe size will have tobe calculated. From the formulaon page 3:

V =2.4 x Q x Vs

ASolving for area the formulabecomes:

A =2.4 x Q x Vs

V

Select a velocity of 10,000 ft/min.(which is within the processvelocity range of 8,000 - 12,000ft/min.) and determine Vs (specif-ic volume) of 1.47 ft3/lb (from theSteam Table on page 7). The for-mula is now:

A =2.4 x 35,417 x 1.47

= 12.5 in2

10,000From Tables 38 and 39 (page 81)the pipe closest to this area is 4"schedule 40 or 5" schedule 80.

SYSTEMDESIGN

Table 2: Superheated Steam Correction Factor Gauge Saturated

Pressure Temp. TOTAL STEAM TEMPERATURE IN DEGREES FARENHEITPSI ˚F 340 360 380 400 420 440 460 480 500 520 540 560 580 600 620 640 660 680

15 250 .99 .99 .98 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86 .86 .8520 259 .99 .99 .98 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86 .86 .8540 287 1.00 .99 .99 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86 .86 .8560 308 1.00 .99 .99 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86 .86 .8580 324 1.00 1.00 .99 .99 .98 .97 .96 .94 .93 .92 .91 .90 .89 .88 .87 .86 .86 .85

100 338 – 1.00 1.00 .99 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86 .85120 350 – 1.00 1.00 .99 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86 .85140 361 – – 1.00 1.00 .99 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86 .85160 371 – – – 1.00 .99 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86180 380 – – – 1.00 .99 .98 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86

200 388 – – – 1.00 .99 .99 .97 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86220 395 – – – 1.00 1.00 .99 .98 .96 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86240 403 – – – – 1.00 .99 .98 .97 .95 .94 .93 .92 .91 .90 .89 .88 .87 .86260 409 – – – – 1.00 .99 .98 .97 .96 .94 .93 .92 .91 .90 .89 .88 .87 .86280 416 – – – – 1.00 1.00 .99 .97 .96 .95 .93 .92 .91 .90 .89 .88 .87 .86

300 422 – – – – – 1.00 .99 .98 .96 .95 .93 .92 .91 .90 .89 .88 .87 .86350 436 – – – – – 1.00 1.00 .99 .97 .96 .94 .93 .92 .91 .90 .89 .88 .87400 448 – – – – – – 1.00 .99 .98 .96 .95 .93 .92 .91 .90 .89 .88 .87450 460 – – – – – – – 1.00 .99 .97 .96 .94 .93 .92 .91 .89 .88 .87500 470 – – – – – – – 1.00 .99 .98 .96 .94 .93 .92 .91 .90 .89 .88

550 480 – – – – – – – – 1.00 .99 .97 .95 .94 .92 .91 .90 .89 .88600 489 – – – – – – – – 1.00 .99 .98 .96 .94 .93 .92 .90 .89 .88650 497 – – – – – – – – – 1.00 .99 .97 .95 .94 .92 .91 .90 .89700 506 – – – – – – – – – 1.00 .99 .97 .96 .94 .93 .91 .90 .89750 513 – – – – – – – – – 1.00 1.00 .98 .96 .95 .93 .92 .90 .89

800 520 – – – – – – – – – – 1.00 .99 .97 .95 .94 .92 .91 .90850 527 – – – – – – – – – – 1.00 .99 .98 .96 .94 .93 .92 .90900 533 – – – – – – – – – – 1.00 1.00 .99 .97 .95 .93 .92 .90950 540 – – – – – – – – – – – 1.00 .99 .97 .95 .94 .92 .91

1000 546 – – – – – – – – – – – 1.00 .99 .98 .96 .94 .93 .91

700 720 740 760

.84 .83 .83 .82

.84 .83 .83 .82

.84 .84 .83 .82

.84 .84 .83 .82

.84 .84 .83 .82

.85 .84 .83 .82

.85 .84 .83 .82

.85 .84 .83 .82

.85 .84 .83 .82

.85 .84 .83 .83

.85 .84 .83 .83

.85 .84 .84 .83

.85 .84 .84 .83

.85 .85 .84 .83

.85 .85 .84 .83

.86 .85 .84 .83

.86 .85 .84 .83

.86 .85 .84 .84

.86 .86 .84 .84

.87 .86 .85 .84

.87 .86 .85 .84

.87 .86 .85 .84

.87 .86 .86 .85

.88 .87 .86 .85

.88 .87 .86 .85

.88 .87 .86 .85

.89 .88 .87 .86

.89 .88 .87 .86

.89 .88 .87 .86

.90 .89 .87 .86

Properties Of Saturated Steam

7

SYSTEMDESIGN

Table 3: Properties of Saturated SteamSpecific Specific

Gauge Temper- Heat in Btu/lb. Volume Gauge Temper- Heat in Btu/lb. VolumePressure ature Cu. ft. Pressure ature Cu. ft.

PSIG °F Sensible Latent Total per lb. PSIG °F Sensible Latent Total per lb.

25 134 102 1017 1119 142.0 185 382 355 843 1198 2.2920 162 129 1001 1130 73.9 190 384 358 841 1199 2.2415 179 147 990 1137 51.3 195 386 360 839 1199 2.1910 192 160 982 1142 39.4 200 388 362 837 1199 2.145 203 171 976 1147 31.8 205 390 364 836 1200 2.090 212 180 970 1150 26.8 210 392 366 834 1200 2.051 215 183 968 1151 25.2 215 394 368 832 1200 2.002 219 187 966 1153 23.5 220 396 370 830 1200 1.963 222 190 964 1154 22.3 225 397 372 828 1200 1.924 224 192 962 1154 21.4 230 399 374 827 1201 1.895 227 195 960 1155 20.1 235 401 376 825 1201 1.856 230 198 959 1157 19.4 240 403 378 823 1201 1.817 232 200 957 1157 18.7 245 404 380 822 1202 1.788 233 201 956 1157 18.4 250 406 382 820 1202 1.759 237 205 954 1159 17.1 255 408 383 819 1202 1.72

10 239 207 953 1160 16.5 260 409 385 817 1202 1.6912 244 212 949 1161 15.3 265 411 387 815 1202 1.6614 248 216 947 1163 14.3 270 413 389 814 1203 1.6316 252 220 944 1164 13.4 275 414 391 812 1203 1.6018 256 224 941 1165 12.6 280 416 392 811 1203 1.5720 259 227 939 1166 11.9 285 417 394 809 1203 1.5522 262 230 937 1167 11.3 290 418 395 808 1203 1.5324 265 233 934 1167 10.8 295 420 397 806 1203 1.4926 268 236 933 1169 10.3 300 421 398 805 1203 1.4728 271 239 930 1169 9.85 305 423 400 803 1203 1.4530 274 243 929 1172 9.46 310 425 402 802 1204 1.4332 277 246 927 1173 9.10 315 426 404 800 1204 1.4134 279 248 925 1173 8.75 320 427 405 799 1204 1.3836 282 251 923 1174 8.42 325 429 407 797 1204 1.3638 284 253 922 1175 8.08 330 430 408 796 1204 1.3440 286 256 920 1176 7.82 335 432 410 794 1204 1.3342 289 258 918 1176 7.57 340 433 411 793 1204 1.3144 291 260 917 1177 7.31 345 434 413 791 1204 1.2946 293 262 915 1177 7.14 350 435 414 790 1204 1.2848 295 264 914 1178 6.94 355 437 416 789 1205 1.2650 298 267 912 1179 6.68 360 438 417 788 1205 1.2455 300 271 909 1180 6.27 365 440 419 786 1205 1.2260 307 277 906 1183 5.84 370 441 420 785 1205 1.2065 312 282 901 1183 5.49 375 442 421 784 1205 1.1970 316 286 898 1184 5.18 380 443 422 783 1205 1.1875 320 290 895 1185 4.91 385 445 424 781 1205 1.1680 324 294 891 1185 4.67 390 446 425 780 1205 1.1485 328 298 889 1187 4.44 395 447 427 778 1205 1.1390 331 302 886 1188 4.24 400 448 428 777 1205 1.1295 335 305 883 1188 4.05 450 460 439 766 1205 1.00

100 338 309 880 1189 3.89 500 470 453 751 1204 .89105 341 312 878 1190 3.74 550 479 464 740 1204 .82110 344 316 875 1191 3.59 600 489 473 730 1203 .75115 347 319 873 1192 3.46 650 497 483 719 1202 .69120 350 322 871 1193 3.34 700 505 491 710 1201 .64125 353 325 868 1193 3.23 750 513 504 696 1200 .60130 356 328 866 1194 3.12 800 520 512 686 1198 .56135 358 330 864 1194 3.02 900 534 529 666 1195 .49140 361 333 861 1194 2.92 1000 546 544 647 1191 .44145 363 336 859 1195 2.84 1250 574 580 600 1180 .34150 366 339 857 1196 2.74 1500 597 610 557 1167 .23155 368 341 855 1196 2.68 1750 618 642 509 1151 .22160 371 344 853 1197 2.60 2000 636 672 462 1134 .19165 373 346 851 1197 2.54 2250 654 701 413 1114 .16170 375 348 849 1197 2.47 2500 669 733 358 1091 .13175 377 351 847 1198 2.41 2750 683 764 295 1059 .11180 380 353 845 1198 2.34 3000 696 804 213 1017 .08

IN V

AC

.

Draining Steam Mains

8

Steam main drainage is one of themost common applications forsteam traps. It is important thatwater is removed from steammains as quickly as possible, forreasons of safety and to permitgreater plant efficiency. A build-upof water can lead to waterham-mer, capable of fracturing pipesand fittings. When carried into thesteam spaces of heat exchang-ers, it simply adds to the thicknessof the condensate film andreduces heat transfer. Inadequatedrainage leads to leaking joints,and is a potential cause of wire-drawing of control valve seats.

WaterhammerWaterhammer occurs when a

slug of water, pushed by steampressure along a pipe instead ofdraining away at the low points, issuddenly stopped by impact on avalve or fitting such as a pipebend or tee. The velocities whichsuch slugs of water can achieveare not often appreciated. Theycan be much higher than the nor-mal steam velocity in the pipe,especially when the waterham-mer is occurring at startup.

When these velocities aredestroyed, the kinetic energy in thewater is converted into pressureenergy and a pressure shock isapplied to the obstruction. In mildcases, there is noise and perhapsmovement of the pipe. More severecases lead to fracture of the pipe orfittings with almost explosive effect,and consequent escape of livesteam at the fracture.

Waterhammer is avoided com-pletely if steps are taken to ensurethat water is drained away before itaccumulates in sufficient quantityto be picked up by the steam.

Careful consideration ofsteam main drainage can avoiddamage to the steam main andpossible injury or even loss of life.It offers a better alternative thanan acceptance of waterhammerand an attempt to contain it bychoice of materials, or pressurerating of equipment.

Efficient Steam MainDrainageProper drainage of lines, andsome care in start up methods,not only prevent damage bywaterhammer, but help improvesteam quality, so that equipmentoutput can be maximized andmaintenance of control valvesreduced.

The use of oversized steamtraps giving very generous “safe-ty factors” does not necessarilyensure safe and effective steammain drainage. A number ofpoints must be kept in mind, for asatisfactory installation.1) The heat up method

employed.2) Provision of suitable collect-

ing legs or reservoirs for thecondensate.

3) Provision of a minimum pres-sure differential across thesteam trap.

4) Choice of steam trap typeand size.

5) Proper trap installation.

Heat Up MethodThe choice of steam trap dependson the heat up method adopted tobring the steam main up to fullpressure and temperature. Thetwo most usual methods are:

(a) supervised start up and(b) automatic start up.

A) Supervised Start UpIn this case, at each drain point inthe steam system, a manual drainvalve is fitted, bypassing thesteam trap and discharging toatmosphere.

These drain valves areopened fully before any steam isadmitted to the system. When the“heat up” condensate has beendischarged and as the pressurein the main begins to rise, thevalves are closed. The conden-sate formed under operatingconditions is then dischargedthrough the traps. Clearly, thetraps need only be sized to han-dle the losses from the linesunder operating conditions, givenin Table 5 (page 10).

This heat up procedure ismost often used in large installa-tions where start up of the systemis an infrequent, perhaps even anannual, occurrence. Large heat-ing systems and chemicalprocessing plants are typicalexamples.

SYSTEMDESIGN

Figure 4Trap Boiler header or takeoff separator

and size for maximum carryover. On heavydemand this could be 10% of generating capacity

Separator

Trap Set

SteamSupply

Draining Steam Mains

9

B) Automatic Start UpOne traditional method of achiev-ing automatic start up is simply toallow the steam boiler to be firedand brought up to pressure withthe steam take off valve (crownvalve) wide open. Thus the steammain and branch lines come up topressure and temperature with-out supervision, and the steamtraps are relied on to automatical-ly discharge the condensate as itis formed.

This method is generally con-fined to small installations thatare regularly and frequently shutdown and started up again. Forexample, the boilers in manylaundry and drycleaning plantsare often shut down at night andrestarted the next morning.

In anything but the smallestplants, the flow of steam from theboiler into the cold pipes at startup, while the boiler pressure isstill only a few psi, will lead toexcessive carryover of boilerwater with the steam. Such carry-over can be enough to overloadseparators in the steam takeoff,where these are fitted. Greatcare, and even good fortune, areneeded if waterhammer is to beavoided.

For these reasons, modernpractice calls for an automaticvalve to be fitted in the steamsupply line, arranged so that thevalve stays closed until a reason-able pressure is attained in theboiler. The valve can then bemade to open over a timed periodso that steam is admitted onlyslowly into the distributionpipework. The pressure with theboiler may be climbing at a fastrate, of course, but the slow open-ing valve protects the pipework.

Where these valves areused, the time available to warmup the pipework will be known, asit is set on the valve control. Inother cases it is necessary toknow the details of the boiler startup procedure so that the time canbe estimated. Boilers started fromcold are often fired for a short

time and then shut off while tem-peratures equalize. The boilersare protected from undue stressby these short bursts of firing,which extend the warmup timeand reduce the rate at which con-densation in the mains is to bedischarged at the traps.

Determining Condensate LoadsAs previously discussed there aretwo methods for bringing a steammain “on line”. The supervisedstart up bypasses the traps thusavoiding the large warm up loads.The traps are then sized basedon the running conditions found inTable 5 (page 10). A safety factorof 2:1 and a differential pressureof inlet minus condensate returnpressure.

Systems employing automat-ic start up procedures requiresestimation of the amount of con-densate produced in bringing upthe main to working temperatureand pressure within the timeavailable. The amount of conden-sate being formed and thepressure available to discharge itare both varying continually andat any given moment are indeter-minate due to many unknownvariables. Table 4 (page 10) indi-cates the warm up loads per 100feet of steam main during a one

hour start up. If the start up timeis different, the new load can becalculated as follows:

lbs. of Condensate (Table 4) x 60Warm up time in minutes

= Actual warm-up load.

Apply a safety factor of 2:1and size the trap at a differentialpressure of working steam pres-sure minus condensate returnline presure. Since most driptraps see running loads muchmore often than start up loads,care must be taken when sizingthem for start up conditions. If thestart up load forces the selectionof a trap exceeding the capabilityof the “running load trap,” then thewarm up time needs to beincreased and/or the length ofpipe decreased.

SYSTEMDESIGN

Warm Up Load ExampleConsider a length of 8" main which is to carry steam at 125 psig. Drippoints are to be 150 ft. apart and outside ambient conditions can be aslow as 0°F. Warm-up time is to be 30 minutes.

From Table 4, Warm Up Load is 107 lb./100 ft.For a 150 ft run, load is 107 x 1.5 = 160.5 lb/150 ft.

Correction Factor for 0°F (see Table 4) 1.25 x 160.5 = 200.6 lb/150 ft.A 30 minute warm up time increases the load by

200.6 x 6030

= 401 lb/htotal load

Applying a safety factor of 2:1, the trap sizing load is 802 lb/h. If the backpressure in the condensate return is 0 psig, the trap would be sized fora 125 psi differential pressure.This would result in an oversized trap dur-ing running conditions, calculated at 94 lb/h using Tabe 5 (page 10).Either increase the warm up time to one hour or decrease the distancebetween drip traps.

Draining Steam Mains

10

SYSTEMDESIGN

Table 4: Warm-Up Load in Pounds of Steam per 100 Ft of Steam Main Ambient Temperature 70°F. Based on Sch. 40 pipe to 250 psi, Sch. 80 above 250 except Sch. 120 5" and larger above 800 psi

Steam O°FPressure Main Size Correction

psi 2" 21/2" 3" 4" 5" 6" 8" 10" 12" 14" 16" 18" 20" 24" Factor†0 6•2 9•7 12•8 18•2 24•6 31•9 48 68 90 107 140 176 207 308 1•505 6•9 11•0 14•4 20•4 27•7 35•9 48 77 101 120 157 198 233 324 1•44

10 7•5 11•8 15•5 22•0 29•9 38•8 58 83 109 130 169 213 251 350 1•4120 8•4 13•4 17•5 24•9 33•8 44 66 93 124 146 191 241 284 396 1•3740 9•9 15•8 20•6 90•3 39•7 52 78 110 145 172 225 284 334 465 1•3260 11•0 17•5 22•9 32•6 44 57 86 122 162 192 250 316 372 518 1•2980 12•0 19•0 24•9 35•3 48 62 93 132 175 208 271 342 403 561 1•27

100 12•8 20•3 26•6 37•8 51 67 100 142 188 222 290 366 431 600 1•26125 13•7 21•7 28•4 40 55 71 107 152 200 238 310 391 461 642 1•25150 14•5 23•0 30•0 43 58 75 113 160 212 251 328 414 487 679 1•24175 15•3 24•2 31•7 45 61 79 119 169 224 265 347 437 514 716 1•23200 16•0 25•3 33•1 47 64 83 125 177 234 277 362 456 537 748 1•22250 17•2 27•3 35•8 51 69 89 134 191 252 299 390 492 579 807 1•21300 25•0 38•3 51 75 104 143 217 322 443 531 682 854 1045 1182 1•20400 27•8 43 57 83 116 159 241 358 493 590 759 971 1163 1650 1•18500 30•2 46 62 91 126 173 262 389 535 642 825 1033 1263 1793 1•17600 32•7 50 67 98 136 187 284 421 579 694 893 1118 1367 1939 1•16800 38 58 77 113 203 274 455 670 943 1132 1445 1835 2227 3227 1•156

1000 45 64 86 126 227 305 508 748 1052 1263 1612 2047 2485 3601 1•1471200 52 72 96 140 253 340 566 833 1172 1407 1796 2280 2767 4010 1•1401400 62 79 106 155 280 376 626 922 1297 1558 1988 2524 3064 4440 1•1351600 71 87 117 171 309 415 692 1018 1432 1720 2194 2786 3382 4901 1•1301750 78 94 126 184 333 448 746 1098 1544 1855 2367 3006 3648 5285 1•1281800 80 97 129 189 341 459 764 1125 1584 1902 2427 3082 3741 5420 1•127

†For outdoor temperature of 0°F, multiply load value in table for each main size by correction factor shown.

Table 5: Running Load in Pounds per Hour per 100 Ft of Insulated Steam Main Ambient Temperature 70°F. Insulation 80% efficient. Load due to radiation and convection for saturated steam.

Steam 0°FPressure Main Size Correction

psi 2" 21/2" 3" 4" 5" 6" 8" 10" 12" 14" 16" 18" 20" 24" Factor†10 6 7 9 11 13 16 20 24 29 32 36 39 44 53 1•5830 8 9 11 14 17 20 26 32 38 42 48 51 57 68 1•5060 10 12 14 18 24 27 33 41 49 54 62 67 74 89 1•45

100 12 15 18 22 28 33 41 51 61 67 77 83 93 111 1•41125 13 16 20 24 30 36 45 56 66 73 84 90 101 121 1•39175 16 19 23 26 33 38 53 66 78 86 98 107 119 142 1•38250 18 22 27 34 42 50 62 77 92 101 116 126 140 168 1•36300 20 25 30 37 46 54 68 85 101 111 126 138 154 184 1•35400 23 28 34 43 53 63 80 99 118 130 148 162 180 216 1•33500 27 33 39 49 61 73 91 114 135 148 170 185 206 246 1•32600 30 37 44 55 68 82 103 128 152 167 191 208 232 277 1•31800 36 44 53 69 85 101 131 164 194 214 244 274 305 365 1•30

1000 43 52 63 82 101 120 156 195 231 254 290 326 363 435 1•271200 51 62 75 97 119 142 185 230 274 301 343 386 430 515 1•261400 60 73 89 114 141 168 219 273 324 356 407 457 509 610 1•251600 69 85 103 132 163 195 253 315 375 412 470 528 588 704 1•221750 76 93 113 145 179 213 278 346 411 452 516 580 645 773 1•221800 79 96 117 150 185 221 288 358 425 467 534 600 667 800 1•21

†For outdoor temperature of 0°F, multiply load value in table for each main size by correction factor shown.

Draining Steam Mains

11

Draining Steam MainsNote from the example that inmost cases, other than large dis-tribution mains, 1/2" Thermo-Dynamic® traps have amplecapacity. For shorter lengthsbetween drip points, and for smalldiameter pipes, the 1/2" lowcapacity TD trap more than meetseven start up loads, but on largermains it may be worth fitting par-allel 1/2" traps as in Fig. II-6 (page86). Low pressure mains are bestdrained using float and thermo-static traps, and these traps canalso be used at higher pressures.

The design of drip stationsare fairly simple. The most com-mon rules to follow for sizing thedrip pockets are:1. The diameter of the drip pock-

ets shall be the same size asthe distribution line up to 6inches in diameter.The diame-ter shall be half the size of thedistribution line over 6 inchesbut never less than 6 inches.

2. The length of the drip pocketshall be 1-1/2 times the diam-eter of the distribution line butnot less than 18 inches.

Drip Leg SpacingThe spacing between thedrainage points is often greaterthan is desirable. On a long hori-zontal run (or rather one with afall in the direction of the flow ofabout 1/2" in 10 feet or 1/250)drain points should be provided atintervals of 100 to 200 feet.Longer lengths should be split upby additional drain points. Anynatural collecting points in thesystems, such as at the foot ofany riser, should also be drained.

A very long run laid with a fallin this way may become so lowthat at intervals it must be elevatedwith a riser. The foot of each ofthese “relay points” also requires acollecting pocket and steam trap.

Sometimes the ground con-tours are such that the steammain can only be run uphill. Thiswill mean the drain points shouldbe at closer intervals, say 50 ft.apart, and the size of the mainincreased. The lower steamvelocity then allows the conden-sate to drain in the oppositedirection to the steam flow.

Air venting of steam mains isof paramount importance and isfar too often overlooked. Steamentering the pipes tends to pushthe air already there in front of itas would a piston. Automatic airvents, fitted on top of tees at theterminal points of the main andthe larger branches, will allow dis-charge of this air. Absence of airvents means that the air will passthrough the steam traps (where itmay well slow down the dis-charge of condensate) or throughthe steam using equipment itself.

SYSTEMDESIGN

Figure 5Draining and Relaying Steam Main

Fall 1/2" in 10 FtSteam

Steam Trap

Steam Trap

Steam TrapSteam TrapSteam Trap

Condensate

The majority of steam traps in refineries are installed onsteam main and steam tracing systems. Thoroughdrainage of steam mains/branch lines is essential for effec-tive heat transfer around the refinery and for waterhammerprevention. This holds true for condensate drainage fromsteam tracing lines/jackets, though some degree of back-up (or sub-cooling) is permissible in some applications.

The predominant steam trap installed is a non-repairable type that incorporates a permanent pipelineconnector. Scattered throughout the system are a numberof iron and steel body repairable types.

Most notable failure of steam traps are precipitate for-mation on bucket weep-holes and discharge orifices thateventually plugs the trap shut. A common culprit is valvesealing compound injected into leaking valves which formssmall pellets that settle in low points, such as driplegs/steam traps and on strainer screens making blowdown difficult. This problem also occurs during occasional“system upset” when hydrocarbon contaminants are mis-takenly introduced to the steam system.

A noise detector and/or a temperature-indicatingdevice is required to detect trap failure. Especially costly is

the fact that operators are not allowed to remove traps forrepair when threading from the line is required.Maintenance personnel must be involved.

SolutionUniversal connector steam traps were installed for trial inone of the dirtiest drip stations at the refinery. The trapsheld up under adverse operating conditions requiring onlyperiodic cleaning. Since the time of installation, all failedinverted bucket traps in this service were replaced with uni-versal connector traps. Strainers were installed upstreamof each.

Benefits• The addition of Thermo-Dynamic® traps allowed for eas-

ier field trap testing.• The addition of universal connectors significantly

reduced steam trap installation and repair time.• 33% reduction in steam trap inventory due to standard

trap for all sizes.• Reduced energy loss is significantly reduced using Thermo-

Dynamic® steam traps versus original inverted bucket traps.

Case in Action: Steam Main and Steam Tracing System Drainage

Steam Tracing

12

The temperature of process liquidsbeing transferred through pipelinesoften must be maintained to meetthe requirements of a process, toprevent thickening and solidifica-tion, or simply to protect againstfreezeup. This is achieved by theuse of jacketed pipes, or by attach-ing to the product line one or moreseparate tracer lines carrying aheating medium such as steam orhot water.

The steam usage may be rel-atively small but the tracingsystem is often a major part ofthe steam installation, and thesource of many problems.

Many large users and plantcontractors have their owninhouse rules for tracer lines, butthe following guidelines may beuseful in other cases. We havedealt only with external tracing,this being the area likely to causedifficulties where no existingexperience is available. Externaltracing is simple and thereforecheap to install, and fulfills theneeds of most processes.

External Tracer LinesOne or more heat carrying lines, ofsizes usually from 3/8" up to 1"nominal bore are attached to themain product pipe as in Fig. 6.Transfer of heat to the product linemay be three ways—by conductionthrough direct contact, by convec-tion currents in the air pocketformed inside the insulating jacket,and by radiation. The tracer linesmay be of carbon steel or copper,or sometimes stainless steel.

Where the product line is of aparticular material to suit the fluidit is carrying, the material for thetracer line must be chosen toavoid electrolytic corrosion at anycontact points.

For short runs of tracer, suchas around short vertical pipes, orvalves and fittings, small bore cop-per pipes, perhaps 1/4" bore maybe wound around the product linesas at Fig. 7. The layout should bearranged to give a continuous fallalong the tracers as Fig. 9a rather

than Fig. 9b, and the use of wraparound tracers should be avoidedon long horizontal lines.

A run of even 100 ft. of 6 inchproduct line will have a total ofabout 500 to 600 ft. of wraparound tracer. The pressure dropalong the tracer would be veryhigh and the temperature at theend remote from the supply wouldbe very low. Indeed, this end ofthe tracer would probably containonly condensate and the temper-ature of this water would fall as itgives up heat. Where steam ispresent in the tracer, lifting thecondensate from the multiplicity oflow points increases the problemsassociated with this arrangement.

SYSTEMDESIGN

Figure 6Tracer Attached To Product Line

LaggingProduct

AluminumFoil

Air Space

Tracer

Figure 7Small Bore TracingWraped AroundVertical Product Line

Figure 8Clipping Tracer Around Bends

Figure 9 Continuous Fall On Wrap Around Tracer

Figure 10 Attaching Tracer To Line

Figure 10a Short Run Welds

Figure 10b Continuous Weld

Figure 10c Heat Conducting Paste

Product

Lagging

Tracer

HeatConducting

Paste

9a 9b

Steam Tracing

13

Clip On TracersThe simplest form of tracer is onethat is clipped or wired on to themain product line. Maximum heatflow is achieved when the traceris in tight contact with the productline. The securing clips should beno further apart than 12" to 18"on 3/8" tracers, 18" to 24 on 1/2",and 24" to 36" on 3/4" and larger.

The tracer pipes can be liter-ally wired on, but to maintainclose contact it is better to useeither galvanized or stainlesssteel bands, about 1/2" wide and18 to 20 gauge thickness. Onevery practical method is to use apacking case banding machine.Where tracers are carried aroundbends particular care should betaken to ensure that good contactis maintained by using three ormore bands as in Fig. 8.

Where it is not possible to usebands as at valve bodies, softannealed stainless steel wire 18gauge thick is a useful alternative.Once again, any special needs toavoid external corrosion or elec-trolytic action may lead to thesesuggestions being varied.

Welded TracersWhere the temperature differencebetween the tracer and the prod-uct is low, the tracer may bewelded to the product line. Thiscan be done either by short runwelds as Fig. 10a or by a continu-ous weld as Fig. 10b formaximum heat transfer.

In these cases the tracer issometimes laid along the top ofthe pipe rather than at the bot-tom, which greatly simplifies thewelding procedure. Advocates ofthis method claim that this loca-tion does not adversely affect theheat transfer rates.

Heat Conducting PasteFor maximum heat transfer, it canbe an advantage to use a heatconducting paste to fill the normalhot air gap as in Fig. 10c. Thepaste can be used to improveheat transfer with any of the clip-ping methods described, but it isessential that the surfaces arewirebrushed clean before apply-ing the paste.

Spacer TracingThe product being carried in theline can be sensitive to tempera-ture in some cases and it is thenimportant to avoid any local hotspots on the pipe such as couldoccur with direct contact betweenthe tracer and the line.

This is done by introducing astrip of insulating materialbetween the tracer and the prod-uct pipe such as fiberglass,mineral wool, or packing blocks ofan inert material.

InsulationThe insulation must cover boththe product line and the tracer butit is important that the air spaceremains clear. This can beachieved in more than one way.1. The product line and tracer

can first be wrapped with alu-minum foil, or by galvanizedsteel sheet, held on by wiringand the insulation is thenapplied outside this sheet.Alternatively, small mesh gal-vanized wire netting can beused in the same way asmetal sheet Fig. 11a.

2. Sectional insulation, pre-formed to one or two sizeslarger than the product main,can be used.This has the dis-advantage that it can easilybe crushed Fig. 11b.

3. Preformed sectional insula-tion designed to cover bothproduct line and tracer canbe used, as Fig. 11c.Preformed sectional insula-

tion is usually preferred to plasticmaterial, because being rigid itretains better thickness and effi-ciency. In all cases, the insulationshould be properly finished withwaterproof covering. Most insula-tion is porous and becomesuseless as heat conserving mate-rial if it is allowed to absorb water.Adequate steps may also beneeded to protect the insulationfrom mechanical damage.

SYSTEMDESIGN

Figure 11Insulating Tracer and Product Lines

ProductLagging

TracerAluminum

Foil

Wire Netting

ProductLagging

Tracer

Product

Lagging

Tracer

11b 11c11a

Steam Tracing

14

Sizing of External TracersThe tracing or jacketing of any linenormally aims at maintaining thecontents of the line at a satisfacto-ry working temperature under allconditions of low ambient temper-ature with adequate reserve tomeet extreme conditions.

Remember that on someexposed sites, with an ambientstill air temperature of say 0°F, theeffect of a 15 mph wind will be tolower the temperature to anequivalent of -36°F.

Even 32°F in still air can belowered to an effective 4°F with a20 mph wind—circumstanceswhich must be taken into full con-sideration when studying thetracer line requirements.

Details of prevailing condi-tions can usually be obtainedfrom the local meteorologicaloffice or civil air authority.

Most of the sizing of externaltracers is done by rule of thumb,but the problem which arises hereis what rule and whose thumb?

Rules of thumb are generallybased on the experiences of a cer-tain company on a particularprocess and do not necessarilyapply elsewhere. There are alsowidely differing opinions on the lay-out: some say that multiple tracersshould all be below the center lineof the product line while others say,

with equal conviction, that it is per-fectly satisfactory to space thetracers equally around the line.

Then there are those who willendeavor to size their tracers from3/8", 1/2", 3/4" or 1" and evenlarger pipe: while another schoolof thought says that as tracershave only minute contact with theproduct line it will give much moreeven distribution of heat if all trac-ers are from 1/2" pipe in multiplesto meet the requirements. Thisdoes have the added advantageof needing to hold a stock of onlyone size of pipe and fittings ratherthan a variety of sizes.

For those who like to followthis idea, Table 6 will be useful formost average requirements.

Type A would suffice for mostfuel oil requirements and wouldalso meet the requirement ofthose lines carrying acid, phenol,water and some other chemicals,but in some cases spacersbetween the product line andsteam line would be employed.

The steam pressure is impor-tant and must be chosenaccording to the product temper-ature required.

For noncritical tracing TypesA & B (Table 6) a steam pressureof 50 psi would generally be suit-able. For Type C, a higherpressure and a trap with a hotdischarge may be required.

Jacketed LinesIdeally jacketed lines should beconstructed in no more than 20 ft.lengths and the condensateremoved from each section.Steam should enter at the highestend so that there is a natural fall tothe condensate outlet as Fig. 12a.

When it is considered imprac-tical to trap each length, anumber of lengths up a total of80-100 ft. approx. may be joinedtogether in moderate climates,but in extremely cold parts of theworld 40 ft. should be the maxi-mum. See Fig. 12b.

Always avoid connectingsolely through the bottom loop.This can only handle the conden-sate and impedes the free flow ofsteam as Fig. 12c. As a generalguide, see Table 7.

Although in most cases 1/2"condensate outlet will be ade-quate, it is usual to make this thesame size as the steam connec-tion as it simplifies installation.

External TracersIn horizontal runs, the steam willgenerally flow parallel to the prod-uct line, but as far as possible,steam should enter from the highend to allow free flow of the con-densate to the low end, i.e. itshould always be self-draining.

It is generally consideredpreferable to fit one tracer on thebottom of the line as Fig. 13a, twotracers at 30° as Fig. 13b, threetracers at 45° as Fig. 13c.

Where multiple 1/2" tracersare used, they should be arrangedin loop fashion on either side of theproduct line, as Fig. 14. In verticallines, the tracers would be spaceduniformly, as Fig. 15a & b.

The maximum permissiblelength of tracer will depend to someextent on the size and initial steampressure, but as a general guide3/8” tracers should not exceed 60ft. in length and the limit for all othersizes should be about 150 ft.

Bends and low points in thetracer, as Fig. 16a should alwaysbe avoided. For example, if it isnecessary to carry a tracer lineround a pipe support or flange,

SYSTEMDESIGN

Table 6: Number of 1/2" (15mm) Tracers Usedwith Different Sizes of Product Lines

Type A Type B Type CNoncritical Noncritical Critical

General frost protection or Where solidification may When solidification maywhere solidification may occur at temps between occur at temps between

occur at temps below 75°F 75-150°F 150-300°F

Product Number of 1/2" Number of 1/2" Number of 1/2"Line Size Tracers Tracers Tracers1" 1 1 111/2" 1 1 22" 1 1 23" 1 1 34" 1 2 36" 2 2 38" 2 2 310"-12" 2 3 614"-16" 2 3 818"-20" 2 3 10

Steam Tracing

15

this should be done in the hori-zontal plane, Fig. 16b.

Where it is essential to main-tain the flow of heat to theproduct, the tracer should betaken up to the back of the flangeFig. 17, and the coupling shouldalways be on the center line ofthe flanged joint.

The same applies to an in-line run where the tracer has tobe jointed. This can be done intwo ways, Fig. 18 or Fig. 19.

Each of these is preferable toFig. 20 which could produce acold spot. Where two tracers areused it can be better to doubleback at a union or flange as Fig.21, rather than jump over it.

ExpansionExpansion in tracer lines is oftenoverlooked. Naturally the steamheated tracer will tend to expandmore than the product line.Wherethe tracer has to pass aroundflanges, the bends are quite ade-quate to take care of theexpansion, Fig. 22.

But where this does not occurand there is a long run of uninter-rupted tracer, it is essential toprovide for expansion which canbe done by forming a completeloop, Fig. 23.

SYSTEMDESIGN

Table 7: Steam Connection Size for Jacketed Lines Product Jacket Steam

Line Diameter Connection2-1/2" 65mm 4" 100mm 1/2" 15mm

3" 80mm 6" 150mm 3/4" 20mm4" 100mm 6" 150mm 3/4" 20mm6" 150mm 8" 200mm 3/4" 20mm8" 200mm 10" 250mm 1" 25mm10" 250mm 12" 300mm 1" 25mm

Figure 13Single and Multiple Tracing

Figure 12aJacketed Lines, Drained Separately

Figure 12bJacketed Lines, Connected

Figure 12cIncorrect Arrangement of Jacketed Lines

13a 13b 13c

Figure 14Multiple Tracing

Figure 15 Vertical Tracing

15a 15b

Figure 16a Incorrect Arrangement

Figure 16b Correct Arrangement

Figure 17

Figure 18

Figure 22Correct Arrangement

Figure 19 for Tracer-line Joints

Figure 20 Incorrect Arrangement

Figure 21Dual Tracer Double Back

Figure 23Expansion Arrangementson Long Tracers

Steam

SteamFall

Fall

Steam TrapSteam Trap

SteamTrap

Steam Trap

Steam

General Installation

Steam Tracing

16

Tracer Steam DistributionIt is important that the steam sup-ply should always be taken from asource which is continuouslyavailable, even during a normalshut down period.

Tracer lines and jacketed pipemay have to work at any steampressure (usually in the rangebetween 10 and 250 psi, butalways choose the lowest pres-sure to give the required producttemperature. Excessively highpressures cause much waste andshould only be used where a highproduct temperature is essential).

To suit product temperaturerequirements, it may be necessaryto use steam at different pres-sures. It should be distributed atthe highest pressure and reduceddown to meet the lower pressurerequirements. A Reducing Valvecan be used for this purpose, Fig.24. Note: it may be necessary tosteam trace the valve body to pre-vent damage due to freezing..

A number of tracers can besupplied from one local distribu-tion header. This header shouldbe adequately sized to meet themaximum load and drained at itslow point by a steam trap as Fig.25. All branches should be takenoff the top of this header, onebranch to each tracer line. Thesebranches should be fitted withisolating valves.

Don’t undersize these branchconnections (1/2" supply to even a3/8" tracer will avoid undue pres-sure drop) and serve only tracers

local to the header, otherwise highpressure drop may result.

The size of the header will, ofcourse, depend upon the steampressure and the total load on thetracers but as a general guide,see Table 8:

Tracer Trap SizingSubcooled discharge traps areusually a good choice for tracerservice.Tracing loads are approx-imately 10 to 50 lb./hr., and eachtracer requires its own low capaci-ty trap.

No two tracers can haveexactly the same duty, so grouptrapping two or more tracers toone trap can considerably impairthe efficiency of heat transfer, seeFig. 26 and Fig. 27.

Even with multiple tracers ona single product line, each tracer

should be separately trapped—Fig. 28.

When branched tracers aretaken to serve valves, then eachshould be separately trapped,Figs. 29, 30, 31 and 32.

SYSTEMDESIGN

Table 8 Recommended header size

for supplying steam tracer lines

Header Size Number of 1/2" Tracers3/4" 21" 3-5

11/2" 6-152" 16-30

Recommended header sizefor condensate lines

Header Size Number of 1/2" Tracers1" Up to 5

11/2" 6-102" 11-25 Figure 28

Header Steam Trap

Tracers

Figure 27Correct Arrangement

Figure 26Incorrect Arrangement

Figure 25

Steam Trap

Steam Trap

Steam Trap

Steam Trap

Steam TrapSteamTrap

Steam Trap

Steam Trap

Steam

Steam

Steam

3/8" (10mm) OD1/4" (6mm) Bore

3/8" (10mm) OD, 1/4" (6mm) Bore

Figure 31Tracer Lines Around Pump Casing

Figure 29

Figure 30

Figure 24Spirax SarcoReducingValve

Steam

Steam

Steam

Steam Tracing

17

Important—Getting Rid of the MuckPipes delivered to the site maycontain mill scale, paint, preserv-ing oils, etc. and during storageand erection will collect dirt, sand,weld splatter and other debris, sothat on completion, the averagetracer line contains a consider-able amount of “muck.”

Hydraulic testing will convertthis “muck” into a mobile sludgewhich is not adequately washedout by simply draining down aftertesting.

It is most important that thelines are properly cleaned byblowing through with steam to anopen end before diverting to thesteam traps.

Unless this is done, the trapswill almost certainly fail to operatecorrectly and more time will bespent cleaning them out when theplant is commissioned.

Steam Traps For Tracer LinesAlmost any type of steam trapcould be used to drain tracerlines, but some lend themselvesto this application better than oth-ers. The traps should bephysically small and light inweight, and as they are often fit-ted in exposed positions, theyshould be resistant to frost. Thetemperature at which the conden-sate is discharged by the trap isperhaps the most important con-sideration when selecting thetype of trap.

Thermo-Dynamic® traps arethe simplest and most robust ofall traps, they meet all of theabove criteria and they dischargecondensate at a temperatureclose to that of steam. Thus theyare especially suitable on thosetracing applications where theholding back of condensate in thetracer line until it has subcooledwould be unacceptable. Tracersor jackets on lines carrying sul-phur or asphalt typify theseapplications where the tracermust be at steam temperaturealong its whole length.

It must be remembered thatevery time a Thermo-Dynamic®

trap opens, it discharges conden-sate at the maximum ratecorresponding to the differentialpressure applied. The instanta-neous release rates of the steamflashing off the condensate canbe appreciable, and care is need-ed to ensure that condensatereturn lines are adequately sized

if high back pressures are to beavoided. Thus, the use of sweptback or “y” connections from trapdischarges into common headersof generous size will help avoidproblems.

Where the traps are exposedto wind, rain or snow, or low ambi-ent temperatures, the steambubbles in the top cap of the trapcan condense more quickly, lead-ing to more rapid wear. Specialinsulating caps are available forfitting to the top caps to avoid this,Fig. 33.

In other non-critical applica-tions, it can be convenient andenergy efficient to allow the con-densate to sub-cool within thetracer before being discharged.This enables use to be made ofsome of the sensible heat in thecondensate, and reduces or eveneliminates the release of flashsteam. Temperature sensitivetraps are then selected, usingeither balanced pressure orbimetallic elements.

The bimetallic traps usuallydischarge condensate at somefairly constant differential such as50°F below condensing tempera-tures, and tend to give acontinuous dribble of condensatewhen handling tracer loads, help-ing minimize the size ofcondensate line needed. Theyare available either in maintain-able versions, with a replaceableelement set which includes thevalve and seat as well as thebimetallic stack, or as sealednon-maintainable units asrequired.

Balanced pressure traps nor-mally operate just below steamtemperature, for critical tracingapplications, see Fig. 34.

The trap is especially suitablewhere small quantities ofcondensate are produced, onapplications where sub-cooling isdesirable, and where the conden-sate is not to be returned to therecovery system.

SYSTEMDESIGN

Figure 32Typical Instrument Tracing

Steam Trap

Steam

3/8" (10mm) OD1/4" (6mm) Bore

1/2" (15mm) OD

Figure 34Balanced Pressure Tracer Trap

Figure 33Insulating Cap forThermo-Dynamic®

Trap

Steam Tracing

18

A similar but maintainabletype intended for use on instru-ment tracer lines, where thephysical size of the trap is impor-tant as well as its operatingcharacteristics is shown in Fig. 35.

Just as the distribution ofsteam is from a common header,it often is convenient to connect anumber of traps to a commoncondensate header and this sim-plifies maintenance. As noted, thedischarge should preferably enterthe header through swept con-nections and the headers beadequately sized as suggested inTable 8 (page 16).

SYSTEMDESIGN

During steam tracing project design, it was found that fivethousand feet of 2" product piping was to be traced with150 psig steam. Product temperature was to be maintainedat 100°F, with maximum allowable temperature of 150°Fand a minimum allowable temperature of 50°F.

Of particular concern was the fact that the pipelinewould always be full of the product, but flow would beintermittent. Overheating could be a real problem. In addi-tion, the tracing system had to be protected from freezing.

SolutionThe 5,000 feet of product piping was divided into 30 sep-arate traced sections including: a cast steel temperatureregulator, a bronze temperature control valve used as ahigh limit safety cutout, a sealed balanced pressure ther-mostatic steam trap, a vacuum breaker, and pressureregulators supplying steam to all 30 tracing sections. Eachsection operates effectively at the desired temperature,regardless of flow rate or ambient temperature.

Benefits• The chance of product damage from overheating is min-

imized and steam consumption is reduced throughsteam pressure reduction (150 psig to 50 psig) with thepressure regulator.

• The product temperature is maintained at a consistentset temperature, maximizing process control under allflow conditions with the temperature regulator.

• Product damage from overheating is prevented throughuse of the high limit safety cutout. The system will shutdown completely, should the temperature regulator over-shoot its set point.

• The tracing system is protected from freezing with thesealed balanced pressure thermostatic steam trap dis-charging to drain. Thorough drainage is also facilitatedby the vacuum breaker.

Case in Action: Product Steam Tracing with Temperature Control and Overheat Protection

These may be increasedwhere high pressures and trapsdischarging condensate at nearsteam temperature are used, ordecreased with low pressuresand traps discharging cooler con-densate.

Temperature Controlof TracerWhere it is essential to preventoverheating of the product, orwhere constant viscosity isrequired for instrumentation,automatic temperature control isfrequently used.

On many systems, the sim-plest way to achieve control is touse a reducing valve on thesteam supply to the tracer lines orjacket. This can be adjusted in thelight of experience to give the cor-rect steam pressure to producethe required product temperature.

Clearly this is an approximateway to control product tempera-ture and can only be used wherethe product flow is fairly constant.Where closer control is required,the simple direct acting tempera-

Figure 35Maintainable Balanced PressureTracer Trap.

ture control often provides aneconomic solution. This will giveclose control and since it is notnecessary to provide either elec-tric power or compressed air, thefirst cost and indeed the runningcosts are low.

Pressure Reducing Stations

19

Pressure Reducing StationsIt is a mistake to install even thebest of pressure reducing valvesin a pipeline without giving somethought to how best it can behelped to give optimal perfor-mance.

The valve selected should beof such a size that it can handlethe necessary load, but oversiz-ing should be avoided.The weightof steam to be handled in a giventime must be calculated or esti-mated, and a valve capable ofpassing this weight from thegiven upstream pressure to therequired downstream pressure ischosen. The valve size is usuallysmaller than the steam pipeseither upstream or downstream,because of the high velocitieswhich accompany the pressuredrop within the valve.

Types of Pressure ReducingValves are also important andcan be divided into three groupsof operation as follows:

Direct Operated ValvesThe direct acting valve shown inFig. II-17 (page 91) is the sim-plest design of reducing valve.

This type of valve has twodrawbacks in that it allows greaterfluctuation of the downstreampressure under unstable loaddemands, and these valves haverelatively low capacity for theirsize. It is nevertheless perfectlyadequate for a whole range ofsimple applications where accu-rate control is not essential andwhere the steam flow is fairlysmall and constant.

Pilot Operated ValvesWhere accurate control of pres-sure or large capacity is required,a pilot operated reducing valveshould be used. Such a valve isshown in Fig. II-12 (page 89).

The pilot operated designoffers a number of advantages overthe direct acting valve. Only a verysmall amount of steam has to flowthrough the pilot valve to pressurizethe main diaphragm chamber and

fully open the main valve. Thus,only very small changes in down-stream pressure are necessary toproduce large changes in flow. The“droop” of pilot operated valves istherefore small. Although any risein upstream pressure will apply anincreased closing force on the mainvalve, this is offset by the force ofthe upstream pressure acting onthe main diaphragm.The result is avalve which gives close control ofdownstream pressure regardlessof variations on the upstream side.

Pneumatically OperatedValvesPneumatically operated controlvalves, Fig. II-20 (page 93), withactuators and positioners beingpiloted by controllers, will providepressure reduction with evenmore accurate control.

Controllers sense down-stream pressure fluctuations,interpolate the signals and regu-late an air supply signal to apneumatic positioner which in turnsupplies air to a disphragm open-ing a valve. Springs are utilized asan opposing force causing thevalves to close upon a loss orreduction of air pressure appliedon the diaphragm. Industrysophistication and control needsare demanding closer and moreaccurate control of steam pres-sures, making pneumatic controlvalves much more popular today.

Piping And Noise Considera-tionThe piping around a steam pres-sure reducing valve must beproperly sized and fitted for bestoperation. Noise level of a reduc-ing station is lowest when thevalve is installed as follows:1. Avoid abrupt changes in

direction of flow. Use longradius bends and “Y” pipinginstead of “T” connections.

2. Limit approach and exitsteam velocity to 4000 to6000 FPM.

3. Change piping gradually

before and after the valve withtapered expanders, or changepipe only 1 or 2 sizes at a time.

4. Provide long, straight, full-sizeruns of heavy wall pipe onboth sides of the valve, andbetween two-stage reductionsto stabilize the flow.

5. Use low pressure turndownratios (non-critical.)

6. Install vibration absorbingpipe hangers and acousticalinsulation.Most noise is generated by a

reducing valve that operates atcritical pressure drop, especiallywith high flow requirements.Fitting a noise diffuser directly tothe valve outlet will reduce thenoise level by approx. 15 dBA.

It must also be rememberedthat a valve designed to operate onsteam should not be expected towork at its best when supplied witha mixture of steam, water and dirt.

A separator, drained with asteam trap, will remove almost allthe water from the steam enteringthe pressure reducing set. Thebaffle type separator illustrated inFig. 36 has been found to be veryeffective over a broad range offlows.

SYSTEMDESIGN

Figure 36Moisture Separator for Steam or Air

Pressure Reducing Stations

20

PRV Station ComponentsA stop valve is usually needed sothat the steam supply can be shutoff when necessary, and thisshould be followed by a line sizestrainer. A fine mesh stainlesssteel screen in the strainer willcatch the finer particles of dirtwhich pass freely through stan-dard strainers. The strainer shouldbe installed in the pipe on its side,rather than in the conventionalway with the screen hangingbelow the pipe. This is to avoid thescreen space acting as a collect-ing pocket for condensate, sincewhen installed horizontally thestrainer can be self-draining

Remember that water whichcollects in the conventionally pipedstrainer at times when the reducingvalve has closed, will be carriedinto the valve when it begins toopen. This water, when forcedbetween the valve disc and seat ofthe just-opening valve, can leadrapidly to wire-drawing, and theneed for expensive replacements.

Pressure gauges at each sideof the reducing valve allow its per-formance to be monitored. At thereduced pressure side of the valve,a relief or safety valve may berequired. If all the equipment con-nected on the low pressure side iscapable of safely withstanding theupstream pressure in the event ofreducing valve failure, the reliefvalve may not be needed. It maybe called for if it is sought to protectmaterial in process from overlyhigh temperatures, and it is essen-tial if any downstream equipmentis designed for a pressure lowerthan the supply pressure.

Steam Safety Valve SizingWhen selecting a safety valve, thepressure at which it is to openmust be decided. Opening pres-sure must be below the limitationsof the downstream equipment yetfar enough above the normalreduced pressure that minor fluc-tuations do not cause opening ordribbling. Type “UV” Safety Valvesfor unfired pressure vessels aretested to ASME Pressure VesselCode, Section VIII and achieverated capacity at an accumulatedpressure 10% above the set-to-

open pressure. Safety valves foruse on boilers carry a “V” stampand achieve rated capacity at only3% overpressure as required bySection I of the Code.

The capacity of the safetyvalve must then equal or exceed

SYSTEMDESIGN

Figure 37Typical Installation of Single Reducing Valve with Noise Diffuser

the capacity of the pressurereducing valve, if it should failopen when discharging steamfrom the upstream pressure to theaccumulated pressure at the safe-ty valve. Any bypass line leakagemust also be accounted for.

Figure 38Typical Installationof Two ReducingValves in Parallel

Separator

PressureSensing Line

ReducingValve

Figure 39Two-Stage Pressure Reducing Valve Stationwith Bypass Arrangement to Operate EitherValve Independently on Emergency Basis

Safety Valve

Diffuser

Trap Set

Downstream Isolating Valve isneeded only with an alternativesteam supply into the L.P. System

Bypasses may be prohibitedby local regulation or byinsurance requirements

Parallel and Series Operation of Reducing Valves

21

Parallel OperationIn steam systems where loaddemands fluctuate through a widerange, multiple pressure controlvalves with combined capacitiesmeeting the maximum load per-form better than a single, largevalve. Maintenance needs, down-time and overall lifetime cost canall be minimized with this arrange-ment, Fig. 38 (page 20).

Any reducing valve must becapable of both meeting its maxi-mum load and also modulatingdown towards zero loads whenrequired. The amount of loadturndown which a given valve cansatisfactorily cover is limited, andwhile there are no rules whichapply without exception, if the lowload condition represents 10% orless of the maximum load, twovalves should always be pre-ferred. Consider a valve whichmoves away from the seat by 0.1inches when a downstream pres-sure 1 psi below the set pressureis detected, and which then pass-es 1,000 pounds per hour ofsteam. A rise of 0.1 psi in thedetected pressure then movesthe valve 0.01 inches toward the

seat and reduces the flow byapproximately 100 pph, or 10%.

The same valve might laterbe on a light load of 100 pph totalwhen it will be only 0.01 inchesaway from the seat. A similar risein the downstream pressure of0.1 psi would then close the valvecompletely and the change inflow through the valve which was10% at the high load, is now100% at low load. The figureschosen are arbitrary, but the prin-ciple remains true that instabilityor “hunting” is much more likelyon a valve asked to cope with ahigh turndown in load.

A single valve, when used inthis way, tends to open and close,or at least move further open andfurther closed, on light loads. Thisaction leads to wear on both theseating and guiding surfaces andreduces the life of thediaphragms which operate thevalve. The situation is worsenedwith those valves which use pis-tons sliding within cylinders toposition the valve head. Frictionand sticking between the slidingsurfaces mean that the valvehead can only be moved in a

series of discreet steps.Especially at light loads, suchmovements are likely to result inchanges in flow rate which aregrossly in excess of the loadchanges which initiate them.Load turndown ratios with piston-operated valves are almostinevitably smaller than wherediaphragm-operated valves arechosen.

Pressure Settingsfor Parallel ValvesAutomatic selection of the valveor valves needed to meet givenload conditions is readilyachieved by setting the valves tocontrol at pressures separated byone or two psi. At full load, orloads not too much below fullload, both valves are in use. Asthe load is reduced, the controlledpressure begins to increase andthe valve set at the lower pres-sure modulates toward the closedposition. When the load can besupplied completely by the valveset at the higher pressure, theother valve closes and with anyfurther load reduction, the valvestill in use modulates through itsown proportional band.

SYSTEMDESIGN

As part of a broad scope strategy to reduce operatingcosts throughout the refinery, a plan was established toeliminate all possible steam waste. The focus of the planwas piping leaks, steam trap failures and steam pressureoptimization.

Programs having been previously established todetect/repair steam trap failures and fix piping leaks, par-ticular emphasis was placed on steam pressureoptimization. Results from a system audit showed that aconsiderable amount of non-critical, low temperature trac-ing was being done with 190 psi (medium pressure)steam, an expensive overkill. It appeared that the mediumpressure header had been tapped for numerous smalltracing projects over the years.

SolutionRefinery engineers looked for ways to reduce pres-

sure to the tracer lines. Being part of a cost-cuttingexercise, it had to be done without spending large sums ofcapital money on expensive control valves. The self-con-

tained cast steel pressure regulators and bronze reducingvalves were chosen for the job. In 1-1/2 years, approxi-mately 40 pressure regulators and hundreds of bronzereducing valves have been installed at a cost of $250K.Annualized steam energy savings are $1.2M/year. Morespecifically, in the Blending and Shipping Division,$62,640 was saved during the winter of 1995, compared tothe same period in 1994.

Benefits• Low installed cost. The Spirax Sarco regulators and

bronze reducing valves are completely self-contained,requiring no auxiliary controllers, positioners, convert-ers, etc.

• Energy savings worth an estimated $1.2M/year.• The utilities supervisor who worked closely with Spirax

Sarco and drove the project through to successful com-pletion received company wide recognition and apromotion in grade.

Case in Action: Elimination of Steam Energy Waste

Parallel and Series Operation of Reducing Valves

22

This can be clarified by anexample. Suppose that a maxi-mum load of 5,000 lb/h at 30 psican be supplied through onevalve capable of passing 4,000lb/h and a parallel valve capableof 1,300 lb/h. One valve is set at29 psi and the other at 31 psi. Ifthe smaller valve is the one set at31 psi, this valve is used to meetloads from zero up to 1,300 lb/hwith a controlled pressure atapproximately 31 psi. At greaterloads, the controlled pressuredrops to 29 psi and the largervalve opens, until eventually it ispassing 3,700 lb/h to add to the1,300 lb/h coming through thesmaller valve for a total of 5,000lb/h.

There may be applicationswhere the load does not normallyfall below the minimum capacityof the larger valve. It would thenbe quite normal to set the 4,000lb/h valve at 31 psi and to supple-ment the flow through the 1,300lb/h valve at 29 psi in those fewoccasions when the extra capaci-ty was required.

Sometimes the split betweenthe loads is effectively unknown.It is usual then to simply selectvalves with capacities of 1/3 and2/3 of the maximum with thesmaller valve at the slightly high-er pressure and the larger one atthe slightly lower pressure.

Two-Stageor Series OperationWhere the total reduction in pres-sure is through a ratio of more than10 to 1, consideration should begiven to using two valves in series,Fig.39 (page 20).Much will dependon the valves being used, on thetotal pressure reduction neededand the variations in the load. PilotOperated controls have been usedsuccessfully with a pressure turn-down ratio as great as 20 to 1, andcould perhaps be used on a fairlysteady load from 100 psig to 5 psi.The same valve would probably beunstable on a variable load, reduc-ing from 40 to 2 psi.

There is no hard and fastrule, but two valves in series willusually provide more accuratecontrol. The second, or LowPressure valve, should give the“fine control” with a modest turn-down, with due considerationbeing given to valve sizes andcapacities. A practical approachwhen selecting the turndown ofeach valve, that results in small-est most economical valves, is toavoid having a non-critical drop inthe final valve, and stay close tothe recommended 10 to 1 turn-down.

Series InstallationsFor correct operation of thevalves, some volume betweenthem is needed if stability is to beachieved. A length of 50 pipediameters of the appropriatelysized pipe for the intermediatepressure, or the equivalent vol-ume of larger diameter pipe isoften recommended.

It is important that the down-stream pressure sensing pipesare connected to a straight sec-tion of pipe 10 diametersdownstream from the nearestelbow, tee, valve or other obstruc-tion. This sensing line should bepitched to drain away from thepressure pilot. If it is not possibleto arrange for this and to still con-nect into the top of thedownstream pipe, the sensingline can often be connected to theside of the pipe instead.

Equally, the pipe between thetwo reducing valves shouldalways be drained through astream trap, just as any riserdownstream of the pressurereducing station should bedrained. The same applies wherea pressure reducing valve sup-plies a control valve, and it isessential that the connecting pipeis drained upstream of the controlvalve.

SYSTEMDESIGN

BypassesThe use of bypass lines andvalves should usually be avoided.Where they are fitted, the capaci-ty through the bypass should beadded to that through the wideopen reducing valve when sizingrelief valves. Bypass valves areoften found to be leaking steambecause of wiredrawing of theseating faces when valves havenot been closed tightly.

If a genuine need exists for abypass because it is essential tomaintain the supply of steam,even when a reducing valve hasdeveloped some fault or is under-going maintenance, considera-tion should be given to fitting areducing valve in the bypass line.Sometimes the use of a parallelreducing station of itself avoidsthe need for bypasses.

Back Pressure ControlsA Back Pressure regulator or sur-plussing valve is a derivative of apressure reducing valve, incorpo-rating a reverse acting pilot valve.The pressure sensing pipe is con-nected to the inlet piping so that thepilot valve responds to upstreampressure. Any increase in upstreampressure then opens the reverseacting pilot valve, causing the mainvalve to open, while a fall below theset pressure causes the main valveto close down, Fig. II-18 (page 92).

These controls are useful inflash steam recovery applicationswhen the supply of flash steammay at times exceed the demandfor it.The BP control can then sur-plus to atmosphere any excesssteam tending to increase thepressure within the flash steamrecovery system, and maintainsthe recovery pressure at therequired level.

The control is also useful ineliminating non-essential loads inany system that suffers under-capacity at peak load times,leaving essential loads on line.

Back Pressure Controls arenot Safety Valves and must neverbe used to replace them.

How to Size Temperature and Pressure Control Valves

23

control may or may not be fullyopen. For three-port valves, it isthe difference in pressurebetween the two open ports.Working Pressure. The pressureexerted on the interior of a valveunder normal working conditions.In water systems, it is the algebra-ic sum of the static pressure andthe pressure created by pumps.Set Point. Pressure or tempera-ture at which controller is set.Accuracy of Regulation or“Droop”. Pressure reducingvalve drop in set point pressurenecessary to obtain the publishedcapacity. Usually stated for pilot-operated PRV’s in psi, and as a %of set pressure for direct-actingtypes.Hunting or Cycling. Persistentperiodic change in the controlledpressure or temperature.Control Point. Actual value ofthe controlled variable (e.g. airtemperature) which the sensor istrying to maintain.Deviation. The differencebetween the set point and themeasured value of the controlledvariable. (Example: When setpoint is 70°F and air temperatureis 68°F, the deviation is 2°F.)Offset. Sustained deviation causedby a proportional control taking cor-

rective action to satisfy a load con-dition. (Example: If the set point is70°F and measured room tempera-ture is 68°F over a period, the offsetis 2°F and indicates the action of aproportional control correcting foran increase in heat loss.)Proportional Band or ThrottlingBand. Range of values whichcause a proportional temperaturecontrol to move its valve from fullyopen to fully closed or to throttlethe valve at some reduced motionto fully closed.Time Constant. Time requiredfor a thermal system actuator totravel 63.2% of the total move-ment resulting from anytemperature change at the sen-sor. Time increase when usingseparable well must be included.Dead Zone. The range of valuesof the controlled variable overwhich a control will take up nocorrective action.Rangeability. The ratio betweenthe maximum and minimum con-trollable flow between which thecharacteristics of the valve will bemaintained.Turn-Down Ratio. The ratiobetween the maximum normal flowand minimum controllable flow.Valve Authority. Ratio of a fullyopen control valve pressure dropto system total pressure drop.

SYSTEMDESIGN

Having determined the heating orcooling load required by theequipment, a valve must beselected to handle it. As the valveitself is only part of the completecontrol, we must be acquaintedwith certain terminology used inthe controls field:Flow Coefficient. The means ofcomparing the flow capacities ofcontrol valves by reference to a“coefficient of capacity.” The termCv is used to express this rela-tionship between pressure dropand flow rate. Cv is the rate offlow of water in GPM at 60°F, at apressure drop of 1 psi across thefully open valve.Differential Pressure. The differ-ence in pressure between the inletand outlet ports when the valve isclosed. For three-port valves, it isthe difference between the openand closed ports.Maximum Differential Pressure.The pressure difference betweeninlet and outlet ports of a valve,above which the actuator will notbe able to close the valve fully, orabove which damage may becaused to the valve, whichever isthe smaller.Pressure Drop. The differencebetween the inlet and outlet pres-sures when the valve is passingthe stated quantity. A self-acting

At a furniture manufacturing facility, the water used forbathing logs to prepare them for production was “rolling” inthe front of its containment tanks. The production manag-er had thought that the temperature had to be at least 212°F. Further examination showed the water’s temperature tobe 180°F. The water was “rolling” because the steam,entering the side of the tank, could not be absorbed by thewater before it rose to the surface in the front of the tank.

Cedar logs are cooked for 48 hours, in open top tanksbefore going through a veneer machine. The logs absorbthe hot water, making it easier to slice the wood into strips.The six log baths did not have any temperature controls.Twenty-five psig steam flowed through a 2" coupling intothe side of the tank to heat the water. With the tank sizebeing 12' x 12' x 6', the 105 cedar logs approximately 10'long occupy most of the space in the tank. River water or“condenser water” off of the turbine at 90°F is fed into thetank.

SolutionTwo temperature control valves to be open during start-upwith one closing as it approaches the desired cooking tem-perature. The second smaller valve continues to providesteam to the system until the set-point is reached. As addi-tional steam is required, the smaller valve supplies it. Asparge pipe was also sized and installed.

Benefits:• Payback of this system was less than 2 weeks on

materials and labor.

• Substantial cost savings due to improved energy use.

• Increased profitability by increasing productivity in thesteam system.

Case in Action: Log Bath-Furniture Manufacturing

Valve Sizing For SteamSatisfactory control of steam flow to giverequired pressures in steam lines orsteam spaces, or required temperaturesin heated fluids, depends greatly onselecting the most appropriate size ofvalve for the application.

An oversized valve tends to hunt, withthe controlled value (pressure or tempera-ture), oscillating on either side of thedesired control point. It will always seek tooperate with the valve disc nearer to theseat than a smaller valve which has to befurther open to pass the required flow.Operation with the disc near to the seatincreases the likelihood that any dropletsof water in the steam supply will give riseto wiredrawing. An undersized valve willsimply unable to meet peak load require-ments, startup times will be extended andthe steam-using equipment will be unableto provide the required output.

A valve size should not be deter-mined by the size of the piping intowhich it is to be fitted. A pressure dropthrough a steam valve seat of even a fewpsi means that the steam moves throughthe seat at high velocity. Valve discs andseats are usually hardened materials towithstand such conditions. The velocitiesacceptable in the piping are much lowerif erosion of the pipes themselves is tobe avoided. Equally, the pressure drop ofa few psi through the valve would implya much greater pressure drop along alength of pipe if the same velocity weremaintained, and usually insufficientpressure would be left for the steam-using equipment to be able to meet theload.

Steam valves should be selected onthe basis of the required steam flowcapacity (lb/h) needed to pass, the inletpressure of the steam supply at thevalve, and the pressure drop which canbe allowed across the valve. In mostcases, proper sizing will lead to the useof valves which are smaller than thepipework on either side.

Calculating Condensate LoadsWhen the normal condensate load is not known, the load can beapproximately determined by calculations using the following formula.

General Usage FormulaeHeating water with steam (Exchangers)*

lb/h Condensate = GPM x (1.1) x Temperature Rise °F2

Heating fuel oil with steam

lb/h Condensate = GPM x (1.1) x Temperature Rise °F4

Heating air with steam coils

lb/h Condensate = CFM x Temperature Rise °F800

Steam Radiation

lb/h Condensate = Sq. Ft. EDR4

*Delete the (1.1) factor when steam is injected directly into water

Specialized ApplicationsSterilizers, Autoclaves,

Retorts Heating Solid Material

lb/h Condensate = W x Cp x ∆TL x t

W = Weight of material—lbs.Cp = Specific heat of the material(∆)T = Temperature rise of the material °FL = Latent heat of steam Btu/lbt = Time in hours

Heating Liquids in Steam JacketedKettles and Steam Heated Tanks

lb/h Condensate = G x s.g. x Cp x (∆)T x 8.3L x t

G = Gallons of liquid to be heateds.g. = Specific gravity of the liquidCp = Specific heat of the liquid(∆)T = Temperature rise of the liquid °FL = Latent heat of the steam Btu/lbt = Time in hours

Heating Air with Steam;Pipe Coils and Radiation

lb/h Condensate = A x U x (∆)TL

A = Area of the heating surface in square feetU = Heat transfer coefficient (2 for free convection)(∆)T = Steam temperature minus the air temperature °FL = Latent heat of the steam Btu/lb

How to Size Temperature and Pressure Control Valves

24

SYSTEMDESIGN

Steam Jacketed Dryers

lb/h Condensate = 1000 (Wi - Wf) + (Wi x ∆T)L

Wi = Initial weight of the material—lb/hWf = Final weight of the material—lb/h(∆)T = Temperature rise of the material °FL = Latent heat of steam Btu/lbNote: The condensate load to heat the equipment must be addedto the condensate load for heating the material. Use same formula.

How to Size Temperature and Pressure Control Valves

25

1. For LiquidsCv = GPM Sp. Gr.

√Pressure Drop, psiWhere Sp. Gr. Water = 1GPM = Gallons per minute

2. For Steam (Saturated)a. Critical Flow

When ∆P is greater thanFL

2 (P1/2)

Cv = W 1.83 FLP1

b. Noncritical FlowWhen ∆P is less thanFL

2 (P1/2)

Cv = W 2.1√∆P (P1 + P2)

Where: P1 = Inlet Pressure psiaP2 = Outlet Pressure psiaW = Capacity lb/hrFL = Pressure Recovery Factor

(.9 on globe pattern valves for flow to open)(.85 on globe pattern valves for flow to close)

3. For Air and Other Gasesa. When P2 is 0.53 P1 or less,

Cv = SCFH √Sp. Gr.30.5 P1

Where Sp. Gr. of air is 1.SCFH is Cu. ft. Free Air perHour at 14.7 psia, and 60°F.

b. When P2 is greater than 0.53 P1,

Cv = SCFH √Sp. Gr.61 √(P1 - P2) P2

Where Sp. Gr. of air is 1.SCFH is Cu. Ft. Free Air per Hour at 14.7 psia, and 60°F.

4. Correction for Superheated SteamThe required Valve Cv is the Cv from theformula multiplied by the correction factor.Correction Factor = 1 + (.00065 xdegrees F. superheat above saturation)Example: With 25°F of Superheat,

Correction Factor= 1 + (.00065 x 25)= 1.01625

5. Correction for Moisture ContentCorrection Factor = √Dryness FractionExample: With 4% moisture,

Correction Factor = √1 - 0.04= 0.98

6. Gas—Correction for TemperatureCorrection Factor = 460 + °F

√ 520Example: If gas temperature is 150°F,Correction Factor = 460 + 150

√ 520= 1.083

SYSTEMDESIGN

Temperature Control Valve SizingAfter estimating the amount of steam flow capacity(lbs/hr) which the valve must pass, decide on thepressure drop which can be allowed. Where the min-imum pressure in a heater, which enables it to meetthe load, is known, this value then becomes thedownstream pressure for the control valve. Where itis not known, it is reasonable to take a pressure dropacross the valve of some 25% of the absolute inletpressure. Lower pressure drops down to 10% cangive acceptable results where thermo-hydraulic con-trol systems are used. Greater pressure drops canbe used when it is known that the resulting down-stream pressure is still sufficiently high. However,steam control valves cannot be selected with outputpressures less than 58% of the absolute inlet pres-

sure.This pressure drop of 42% of the absolute pres-sure is called Critical Pressure Drop. The steam thenreaches Critical or Sonic velocity. Increasing thepressure drop to give a final pressure below theCritical Pressure gives no further increase in flow.

Pressure Reducing Valve SizingPressure reducing valves are selected in the sameway, but here the reduced or downstream pressurewill be specified. Capacity tables will list the SteamFlow Capacity (lb/h) through the valves with givenupstream pressures, and varying downstream pres-sures. Again, the maximum steam flow is reached atthe Critical Pressure Drop and this value cannot beexceeded.

It must be noted here that for self-acting regula-tors, the published steam capacity is always given fora stated “Accuracy of Regulation” that differs amongmanufacturers and is not always the maximum thePRV will pass. Thus when sizing a safety valve, theCv must be used.

Cv ValuesThese provide a means of comparing the flow capac-ities of valves of different sizes, type or manufacturer.The Cv factor is determined experimentally and givesthe GPM of water that a valve will pass with a pres-sure drop of 1 psi. The Cv required for a givenapplication is estimated from the formulae, and avalve is selected from the manufacturers catalog tohave an equal or greater Cv factor.

Temperature Control Valves for Steam Service

26

Temperature Control ValvesFor Steam ServiceAs with pressure reducing valves,temperature control valves canbe divided into three groups.Installation of these valves arethe same as pressure reducingstyles in that adequate protectionfrom dirt and condensate must beused as well as stop valves forshutdown during maintenanceprocedures. A noise diffuserand/or a safety valve would nor-mally not be used unless acombination pressure reducingand temperature control, isinstalled. See PRV station com-ponents on page 20 for moreinformation.

Direct Operated ValvesThe direct operated type asshown in Fig. 40 are simple indesign and operation. In thesecontrols, the thrust pin movementis the direct result of a change intemperature at the sensor. Thismovement is transferred throughthe capillary system to the valve,thereby modulating the steamflow. These valves may also beused with hot water. Such a sim-ple relationship between

temperature changes and valvestem movement enables sensorand valve combinations to givepredictable valve capacities for arange of temperature changes.This allows a valve to be selectedto operate with a throttling bandwithin the maximum load propor-tional band. See appropriatetechnical sheets for specific valveproportional bands.

Choice of Proportional Bandis a combination of accuracy andstability related to each applica-tion. However, as controlaccuracy is of primary impor-tance, and as direct operatedcontrols give constant feedbackplus minute movement, we canconcentrate on accuracy, leavingthe controller to look after stabili-ty. Generally, to give light loadstability, we would not select aProportional Band below 2°F.Table 9 gives the span of accept-able Proportional Bands for somecommon heat exchanger applica-tions.

Pilot Operated ValvesGreater steam capacities areobtained using pilot operatedvalves, along with greater accura-

cy due to their 6°F proportionalband. Only a small amount ofsteam has to flow through the pilotto actuate the main diaphragmand fully open the valve. Only verysmall changes of movement with-in the sensor are necessary toproduce large changes in flow.This results in accurate controleven if the upstream steam pres-sure fluctuates.

Both direct and pilot operatedvalve types are self-containedand do not require an externalpower source to operate.

SYSTEMDESIGN

An office paper product manufacturer uses steam in itsprocess for a dry coating applied to the paper. Using apocket ventilation system, air is blown across the paper asit moves through the dryer cans.

The original design included inverted bucket typetraps on the outlet of the steam coils, but the coils are inoverload boxes where outdoor and indoor air mix. Thesteam supply is on a modulating control with maximumpressure of 150 psi. The steam traps discharge into a com-mon header that feeds to a liquid mover pump. The pumphad a safety relief valve on its non-vented receiver.

Problems observed included the inability to maintaindesired air temperatures across the machines, high backpressure on the condensate return system, the doors onthe coil boxes had to be opened to increase air flowsacross the coils, paper machine had to be be slowed downto improve dryness, steam consumption was way up, watermake-up was up and vent lines were blowing live steam tothe atmosphere.

Solution:A pump trap combination was installed on five of the ninesections using a pressure regulator for motive steam sup-

ply reduction to the pumps. Float & thermostatic traps withleak detection devices were also installed for efficiency.Closed doors were then put on the coil boxes.

The back pressure on the return system dropped to anacceptable and reasonable pressure and the steam con-sumption also dropped. Temperature control was achievedand maintained and production increased from 1,000 feetper minute on some products to 1,600 feet per minute.They switched all five sections of the paper coater to 1" lowprofile Pressure Powered Pump with cast iron float & ther-mostatic steam traps. This manufacturer also switchedfrom inverted buckets on heating units to float and thermo-static steam traps with leak detection devices and replacedseveral electric pumps and the liquid mover with PressurePowered Pumps. Replaced all 16 inverted bucket traps onpaper coater with float and thermostatic steam traps withleak detection devices.

Benefits:• Production Increased • Trap failure went from 40% to 14%.• Over a half-million dollars in steam saved during first

year of operation

Case in Action: Dry Coating Process

Table 9 Acceptable Proportional Bandsfor Some Common Applications

ProportionalApplication Band °F

Domestic Hot Water 7-14Heat Exchanger

Central Hot Water 4-7

Space Heating 2-5(Coils, Convectors,Radiators, etc.)

Bulk Storage 4-18

Plating Tanks 4-11

Temperature Control Valves for Steam Service

27

Pneumatically OperatedValves.Pneumatically operated tempera-ture control valves as shown inFig. II-21 (page 93), provide accu-rate control with the ability tochange the setpoint remotely. Acontroller, through a sensor,adjusts the air signal to the valveactuator or positioner which, inturn, opens or closes the valve asneeded. Industry demands formore accurate control of temper-ature and computer interfacing ismaking the pneumatically operat-ed valves grow within themarketplace.

Installation of Tempera-ture Control ValvesThe operation and longevity ofthese valves depends greatly onthe quality of the steam which is fedto them. The components of a tem-perature control valve station aresame as for a pressure reducingvalve, see page 19. In addition,attention must be paid to the loca-tion of the temperature sensingbulb. It should be completelyimmersed in the fluid being sensed,with good flow around the bulb,and, if used with a well, someheatsink material in the well to dis-place the air which prevents heattransfer.The capillary tubing shouldnot be in close proximity to high orlow temperatures and should notbe crimped in any fashion.

Heating Liquids By DirectSteam InjectionWhere noise and dilution of theproduct are not problems thendirect steam injection can beused for heating. Steam injectionutilizes all of the latent heat of thesteam as well as a large portionof the sensible heat. Two meth-ods, sparge pipes and steaminjectors, are used to direct andmix the steam with the product.

Sparge Pipe SizingA sparge pipe is simply a perforatedpipe used to mix steam with a fluidfor heating. Sizing of this pipe isbased on determining the requiredsteam flow, selecting a steam pres-sure within the pipe (normally lessthan 20 psig for non-pressurizedvessels), and calculating the num-ber of holes by dividing the requiredsteam flow by the quantity of steamthat will flow through each spargehole of a specific diameter as deter-mined from Fig. 42. Holes largerthan 1/8" diameter are used only onrelatively deep tanks where thelarger steam bubbles emitted willhave time to condense beforebreaking the liquid surface, orwhere the required number of 1/8"dia. holes becomes unreasonablygreat. The sparge holes should bedrilled 30° below the horizontalspaced approximately 6" apart andone hole at the bottom to permitdrainage of liquid within the pipe,see Fig. 41.The sparge pipe shouldextend completely across the ves-sel for complete and even heating.

SYSTEMDESIGN

Figure 41The sparge pipe diameter can be determined using Fig. 1 (page 4),limiting the maximum velocity to 6000 ft/min. A typical installation isshown on Fig II-42 (page 105).

Figure 40Operating Principle ofDirect Operated Valves

ValveMovement

Thrust Pin Movement(Movement caused byadding temp to sensor)

Sensor Bulb

Capillary

Add 1°F to Sensor

Valve Housing

Thrust Pin

6"

30°

Figure 42Steam Flow through Sparge Holes

50

40

30

20

10

706050403020100Sparge Pipe Pressure psig

Ste

am F

low

- lb

s.p

er h

r.

3/16" Dia.

1/8" Dia.

3/32" Dia.

Temperature Control Valves for Steam Service

28

Steam InjectorUnlike a sparge pipe, a steaminjector is a manufactured devicethat draws in the cold liquid,mixes it with steam within theinjector nozzle and distributes thehot liquid throughout the tank.

SYSTEMDESIGN

Fine steam filtration in the preparation of cheese production isimportant to the quality of the final product. Because the pro-ducer of cheese products was heating cheese vat washdownwater by direct steam injection, a filtration device was addedto enhance product quality by filtering out the particulates.

While pleased with this simple method of heating, therewas some concern that any particulates entering the wash-down water during steam injection may ultimately contaminatethe vats being cleaned, affecting the cheese production.

SolutionDirect steam injection was the best solution for the cheeseproducer, but the concern about the contamination wasvery important.• A separator was installed in the incoming steam supply

line, which removes a high percentage of the entrainedmoisture. A fine mesh screen strainer was installed toremove solid particulate matter.

• A pneumatically actuated two port valve was installed tocontrol tank temperature. The unit throttles the flow ofsteam to the tank based on the signal being transmittedby the temperature controller.

• Having removed the entrained moisture and majority of par-ticulate matter from the steam supply, a cleanable CSF16

stainless steel steam filter was installed which is capable ofremoving finer particles smaller than 5 microns in size.

• A vacuum breaker was added to the system in order toprevent any of the heated water being drawn back upinto the filter during certain periods of operation.

• A stainless steel injector system was installed which iscapable of efficiently mixing large volumes of high pressure steam with the tank contents with little noise ortank vibration. (The customer stipulated the reduction ofnoise levels in the production facility.)

Benefits:• Guaranteed steam purity and assured compliance with

the 3-A Industry Standard• Inexpensive installation compared with alternative heat

exchanger packages available• Cleanable filter element for reduced operating costs

(replacement element and labor costs).• Accurate temperature control using components of the

existing system• Quiet and efficient mixing of the steam and the tank contents• Product contamination is minimized, the cost of which

could be many thousands of dollars, loss of productionor even consumer dissatisfaction.

Case in Action: Cheese Production

The circulation induced by theinjector will help ensure thoroughmixing and avoid temperaturestratification. See Fig. II-43 (page105) for a typical injector installa-tion. Other advantages of the

injector over a sparge pipe isreduced noise levels and the abil-ity to use high pressure steam upto 200 psig. Refer to applicabletechnical information sheets forsizing and selection information.

Temperature control valves for liq-uid service can be divided intotwo groups. Normally associatedwith cooling, these valves canalso be used on hot water.

Direct Operated ValvesThree types are available for liq-uid service and a selection wouldbe made from one of the followingstyles.2-Port Direct-Acting.Normally open valve that the ther-mal system will close on risingtemperature and used primarilyfor heating applications.2-Port Reverse-Acting.Normally closed valve which isopened on rising temperature.For use as a cooling control,valve should contain a continuousbypass bleed to prevent stagnateflow at sensor.

3-Port Piston-Balanced.This valve is piped either forhot/cold mixing or for divertingflow between two branch lines.

Pneumatically OperatedValvesAs with direct operated valves,the pneumatically operated typeshave the same three groups. Themajor difference is they requirean external pneumatic or electric(through a positioner or convert-er) signal from a controller.

Heating And Cooling LoadsFormulas for calculating the heat-ing or cooling load in gallons perminute of water are:Heating Applications:a. Heating water with water

Heating water GPM required= GPM (Load) x TR

∆T1

b. Heating oil with waterHeating water GPM required= GPM (Load) x TR

2 X ∆T1

c. Heating air with waterHeating water GPM required= CFM x TR

400 x ∆T1

Cooling Applications:d. Cooling air compressor

jacket with waterCooling Water GPM required= 42.5 x HP per Cylinder

8.3 x ∆T2

Where:GPM = Gallons per minute waterTR = Temperature rise of

heated fluid, °FCFM = Cubic feet per minute Air∆T1 = Temperature drop of

heating water, °F∆T2 = Temperature rise of

cooling water, °F

Temperature Control Valves for Liquid Service

Temperature Control Valves for Liquid Service

29

Water Valve SizingWater valve capacity is directlyrelated to the square root of thepressure drop across it, not thestatic system pressure. Knowingthe load in GPM water or anyother liquid, the minimum valveCv required is calculated from theallowable pressure drop (∆P):Cv = GPM S.G.

√ ∆P derived from...GPM(Water) = Cv √ ∆P(Other SG Liquids)GPM = Cv ∆P

√ S.G.

If the allowable differential pres-sure is unknown, the followingpressure drops may be applied:• Heating and Cooling systems

using low temperature hotwater (below 212°F)—Size valve at 1 psi to 2-1/2 psidifferential.

• Heating Systems using waterabove 212°F—Size valve on a 2-1/2 to 5 psidifferential.

• Water for process systems—Size valve for pressure dropof 10% up to 20% of the sys-tem pressure.

• Cooling Valves—Size for allowable differentialup to full system pressuredrop when discharging toatmosphere. Be sure tocheck maximum allowablepressure drop of the valveselected. A bellows-balancedtype may be required.

Using Two-Port andThree-Port ValvesOnly two-port valves are used onsteam systems. However, whendealing with controls for water wecan select either two-port orthree-port valves. But we mustconsider the effects of both typeson the overall system dynamics.

A three-port valve, whethermixing or diverting, is fairly closeto being a constant volume valveand tends to maintain constantpressure distribution in the sys-tem, irrespective of the position ofthe valve.

If a two-port valve were used,the flow decreases, the valvecloses and the pressure or headacross it would increase. Thiseffect is inherent in the use oftwo-port valves and can affect theoperation of other subcircuits.

Furthermore, the waterstanding in the mains will oftencool off while the valve is closed.When the valve reopens, thewater entering the heat exchang-er or load is cooler than expected,and it is some time before normalheating can commence. To avoidthis, a small bypass line shouldbe installed across the supplyand return mains. The bypass lineshould be sized to handle flowrate due to mains losses but inthe absence of information, thebypass should be sized for 10%of the design flow rate.

SYSTEMDESIGN

Figure 43Three-Port Mixing Valve in a Closed Circuit(Constant Volume, Variable Temperature)

Figure 43AThree-Port Diverting Valve in a Closed Circuit(Constant Temperature, Variable Volume)

ConstantlyOpen Port

BalanceValve

C

HeatingSystem

Pump

Pump

ConstantlyOpen Port

BalanceValve

Three-Port Valve

Boiler

Boiler

A

A

B

B

O

Z X

Three-Port Valve

O

X Z

C

HeatingPlant orProcessEquipment

Temperature Control Valves for Liquid Service

30

Mixing And DivertingThree-Port ValvesA three-port temperature controlhas one port that is constantlyopen and it is important that thecirculating pump is always posi-tioned on this side of the system.This will prevent the risk of pump-ing against dead end conditionsand allow correct circulation to doits job.

The valve can be used eitherto mix or divert depending uponhow it is piped into the system. Amixing valve has two inlets andone outlet, a diverting valve hasone inlet and two outlets.

Fig. 43 illustrates the three-port valve used as a mixing valvein a closed circuit. It has two inlets(X and Z) and one outlet (O) whichis the permanently open port. PortX is the port open on startup fromcold, while Port Z will normally beclosed on startup from cold. Theamounts of opening in Ports X andZ will be varied to maintain a con-stant outlet temperature from PortO. Thus a certain percentage ofhot boiler flow water will enterthrough Port X to mix with a corre-sponding percentage of coolerreturn water via Port Z.

When the three-port valve isused to blend cold supply waterwith hot water which may be from

another source, for use in show-ers or similar open circuits whereall the water does not recirculate,it is essential that the pressure ofthe supplies be equal. For theseapplications, it is recommendedthat both the X and Z ports be fit-ted with check valves to preventany scalding or other harmfulback-flow condition.

With the valve connected asshown in Fig. 43A, we now have adiverting arrangement. The valvehas one inlet and two outlets. Hotwater enters Port O and is eitherallowed through Port X to theequipment or through Port Z toreturn to the boiler.

The Need for BalancingThe action of a three-port valve ina closed circuit system, whethermixing or diverting, tends tochange the pressure conditionsaround the system much less thandoes a two-port valve. This stabili-ty is increased greatly when abalancing valve is fitted in thebypass (or mixing connection)line. Not fitting a flow balancingvalve may result in short circuitingand starvation of other subcircuits.

The balancing valve is set sothat the resistance to flow in thebypass line equals or exceeds thatin the load part of the subcircuit.

In Fig. 43, the balance valvemust be set so that the resistanceto flow in line B-Z is equal to theresistance to flow in line B-A-X. InFig. 43A, resistance B-Z mustequal resistance X-C-B.

Makeup Air Heating CoilsAir heating coils in vented con-densate return systems,especially preheat coils suppliedwith low pressure steam modulat-ed by a control valve, can presentdifficulties in achieving satisfacto-ry drainage of condensate. Thereis no problem at full load withproperly designed equipment, butpart load conditions often lead toflooding of the coils with conden-sate, followed by waterhammer,corrosion and sometimes byfreeze-up damage. These prob-lems are so widespread that it isworth examining their causes andremedies in some detail.

Coil ConfigurationsThe coils themselves are usuallybuilt with a steam header and acondensate header joined byfinned tubes. The headers may beboth at one side of the unit, withhairpin or U tubes between them,or sometimes an internal steamtube is used to carry the steam tothe remote end of an outer finnedtube. Vertical headers may beused with horizontal finned tubes,

SYSTEMDESIGN

Hydrogen gas is an important ingredient to many oil refin-ing processes. Large multi-stage compressors are locatedin operating sections throughout the refinery. Considerableattention is paid to maintaining gas quality, and keepingliquid from accumulating in the system.

The telltale signs of entrained liquid became evidentas a high-pitched whistling noise was heard coming fromthe compressor sections. It was determined to be theresult of poor cooling water temperature control. The cool-ing water/Glycol mixture leaving the heat exchanger at95°F, circulating through the compressor jacket was caus-ing excess hydrogen condensing on the cold surfaces ofjacket walls. It’s important to maintain the 95°F heatexchanger outlet temperature to assure that sufficiently-cool water/Glycol is supplied to the compressor sectionsnecessary for proper heat transfer.

SolutionA 2" temperature control with adjustable bleed and a sens-ing system was installed on the cooling water/Glycol outletpiping from three stages for each of two compressors.They were set to maintain a discharge temperature of140°F. This had the effect of holding back Glycol in thejacket sufficiently to prevent excess hydrogen condensingwhile, at the same time, maintaining necessary cooling.

Benefits• Reduced energy consumption as hydrogen condensing

is reduced.• Installation of a self-contained control was far less

expensive than a more sophisticated pneumatic typethat was also under consideration.

• System start-up was fast because of the easily-adjust-ed, pre-calibrated sensing system.

• Accurate process temperature control of each jacketresulted from having separate controls on each.

Case in Action: Hydrogen Compressor Cooling Jacket Temperature Control

Makeup Air Heating Coils

31

or sometimes horizontal headersat the bottom of the unit supplyvertical finned tubes. The alterna-tive arrangement has the headersat opposite sides of the unit, eitherhorizontally at top and bottom orvertically at each side.

While each different arrange-ment has its own proponents,some general statements can bemade, including the fact that evenso-called “freeze-proof” coils canfreeze if not properly drained ofcondensate. In “horizontal” coils,the tubes should not be horizontalbut should have a slight fall frominlet to outlet so that condensatedoes not collect in pools butdrains naturally. Steam inlets to“horizontal” headers may be atone end or at mid length, but withvertical headers the steam inlet ispreferably near the top.

Venting Air From CoilsAs steam enters a coil it drives airahead of it to the drain point, or toa remote area furthest from theinlet. Coil size and shape may pre-vent a good deal of air fromreaching the trap and as steamcondenses, a film of air remainsreducing heat transfer. Coils witha center inlet connection make itmore difficult to ensure that air ispushed from the top tubes, thesteam tending to short circuit pastthese tubes to the condensateheader. Automatic air venting ofthe top condensate header ofthese coils is essential. With otherlayouts, an assessment must bemade of the most likely part of theunit in which air and noncondens-able gases will collect. If this is atthe natural condensate drainpoint, then the trap must havesuperior air venting capability anda Float-Thermostatic type is thefirst choice. When an invertedbucket or other type with limitedair capacity is used, an auxiliaryair vent should be piped in parallelabove the trap. As a general rule,a thermostatic vent and vacuumbreaker are desirable on mostcoils to prevent problems.

Waterlogged CoilsThe most common cause of prob-lems, however, is lack of pressurewithin the steam space underpart load conditions to push con-densate through the traps,especially if it is then to be liftedto a return line at high level oragainst a back pressure. Systemsteam pressure lifts condensate,not the trap, and is generally notappreciated how quickly the pres-sure within the steam space canbe reduced by the action of thecontrol valve. When pressureused to push condensate throughthe traps is lost, the system“stalls” and as condensate backsup into the coil, waterloggingproblems of hammering, temper-ature stratification, corrosion andfreeze-up begin. The coil must befitted with a vacuum breaker sothat condensate is able to drainfreely to the trap as shown in Fig.II-27 (page 97) and from the trapby gravity to a vented receiverand return pump. This is especial-ly important when incoming airtemperature can fall below freez-ing. With low coils, this mayrequire the pump to be placed ina pit or lower floor. How to deter-

mine “system stall” conditionsand the solution for draining coilsto a pressurized return is coveredlater in this manual.

Vacuum BreakerAnd Trap LocationA vacuum breaker ensures thatsome differential pressure canalways exist across a trap thatdrains by gravity but any elevationof condensate after the trapreduces the hydraulic head avail-able. Heating is done using anatmospheric air/steam mixture socoil air venting is most important.A vacuum breaker should be fittedto the steam supply pipe, betweenthe temperature control valve andthe coil inlet. It is not recommend-ed to fit a vacuum breaker on thesteam trap where the hydraulichead of water used to push con-densate through the trap wouldhold the vacuum breaker closed.

In systems where the returnpiping is kept under vacuum, areversed swing check valveshould be used and piped toequalize any coil vacuum not toatmosphere, but to the dischargeside of the trap.

SYSTEMDESIGN

Figure 44Air Heater Coils

FinnedTubes

InletInlet

Inlets

Outlets

Outlets

OutletOutlet

Inlet

Air VentLocation

Alternative Steam Inlet andCondensate Outlet Connecitons

On Coils with Verticalor Horizontal Headers

Makeup Air Heating Coils

32

The steam trap must handlelots of air and drain condensateat saturated steam temperaturecontinuously while the load andpressure are changing and thus aFloat-Thermostatic type is recom-mended for all air heating coils.The trap is mounted below thecondensate outlet from the coilwith a vertical drop giving enoughhydraulic head to enable a suit-able size to be selected. A 14"head should be the minimum andrepresents about 1/2 psi, a 28"head about 1 psi, and to reducepossibility of freeze-up, a drop of3 ft. to the trap is recommended.

Preheat/Reheat CoilsThe preheat/reheat coil hookupshown in Fig. II-26 (page 96) mayemploy a direct-acting temperaturecontrol or with larger coils, a quick-er responding pilot-operated typewith a closer control band is rec-ommended. This arrangementallows filtration and perhaps humid-ification of the air to be carried outat the controlled preheat tempera-ture, and the reheat coil brings thedry bulb temperature of the condi-tioned air to the required value fordistribution. The preheat coil isused to heat outside air up to the

intermediate temperature but asoutside temperature increases, thetemperature control lowers thesteam pressure in the preheat coiland condensate drainage tends toslow down. If the coil is being usedwhere design loads occur at sub-zero temperatures, there cansometimes be only atmosphericpressure in the coil, although the airpassing over it is still cold enoughto lead to freeze-up problems.

This difficulty is greatlyreduced if the temperature sensorcontrolling the steam supply to thepreheat coil is set to the neededdistribution temperature. Part loadconditions would then lead firstly tolowering the steam pressure in thereheat coil, where freezing will notoccur, but pressure is maintainedin the preheat coil until outside airtemperatures are above the dan-ger point. Such an arrangementreduces freeze-up problems inmany instances on existing instal-lations, at minimal cost.

Corrosion And Waterham-mer ProblemsCondensate mixed with airbecomes corrosive and assumingthe boiler water treatment is satis-

factory, coil corrosion problemsare usually due to condensateregularly backing up or lying stag-nant on the bottom of the tubesduring shutdown. If the coil istrapped correctly, the most likelycause is an overhead returnwhich prevents the coil from drain-ing. One remedy for this is to fit aliquid expansion steam trap at thelowest piping level, as shown inFig. II-26 (page 96), set to openwhen the temperature dropsbelow 90°F. The coil then drainsonly cold condensate to a sewer.

In high pressure systemswhere waterhammer on startupremains troublesome, a “safetydrain” trap is sometimes used.Thisconsists of a stock 15 psi ratedinverted bucket trap fitted abovethe main trap which discharges todrain whenever coil pressure islow, but due to its design locks shutat higher pressure. While this isuseful on pressurized mains, thesafety trap may require a pressureconsiderably higher than its nomi-nal rating to lock shut and onmodulating service a considerableamount of condensate may bewasted. This makes the combina-tion pump/trap a more viablesolution to this problem.

SYSTEMDESIGN

Typical storage buildings are extremely large and difficult toheat. This example in specific has three floors with approx-imately 486,000 ft2 of floor space and heated with 150 airhandling units. These units are comprised of bay heaters,overhead door heaters and administrative office areaheaters.The minimum steam supply pressure to all of themis 20 psig and are pneumatically controlled.

In the preceding 12 month period, $201,000 wasspent on labor and materials to repair damaged coils. Thecommon problem was condensate standing in the coils,unable to drain, causing erosion due to presence of car-bonic acid and bulging/splitting as a result of freezing.

SolutionStarting with a training session at the facility that addressedthis problem and typical solutions, Spirax Sarco’s localsales office implemented a “Cooperative Research andDevelopment Agreement” (CRDA). The purpose of theagreement was to test a proposed solution includingPressure Powered Pumps™ and Pump/Trap combinationsto eliminate system stall, thereby assuring thorough con-densate drainage, regardless of supply air temperature,control valve turn-down or over-sized heaters.

A test was conducted on four air handling units. Oneunit was hooked up as usual, without Pressure Powered

Pump™ drainage systems. The other three were drainedby either open or closed loop PPP systems. Four days intothe test and the unit without a PPP drainage system hadthree frozen coils. It was found that as outside supply airtemperature dropped below 36˚F, it was necessary to closeoutside dampers and use 100% recirculated air, or thecoils would freeze. The three units drained by PPP sys-tems continued operating trouble-free.

BenefitsEmployee Safety• Improved indoor air quality through the use of a higher

percentage of outside air supply.• Reduced chance of injury by eliminating water leakage on

the floor from broken coils and subsequent slippage.• Fewer burns because there are fewer steam leaks.• Greater employee awareness of hazards because of

training.Cost Savings• Reduced steam and condensate losses resulting in

energy savings.• Reduced cost for management support (paper-work).• Cost savings of up to 30% above the initial installation

cost in a 12 month period.

Case in Action: Air Handling System Steam Coil Drainage

Draining Temperature Controlled Steam Equipment

33

Makeup air heating coils andother heat exchange equipmentwhere the steam supply pressureis modulated to hold a desiredoutflow temperature must alwaysbe kept drained of condensate.Fitting a vacuum breaker andsteam trap, no matter what thesize, does not always result introuble-free operation and prob-lems with noisy, hammering,corroded and especially frozencoils are well documented. Theseproblems are the result of coilflooding at some point wheneither:a. Incoming makeup air increas-

es above minimum designtemperature, or

b. Flow rate through an exchang-er decreases below themaximum equipment output.In a steam system, tempera-

ture regulation actually meanscontrolling the pressure. Under par-tial load conditions, the steamcontroller, whether self-acting,pneumatic or any other type,reduces the pressure until the nec-essary trap differential is eliminated,the system “stalls,” and steam coilsbecome waterfilled coils.

Conditions Creating “Sys-tem Stall”With the steam equipment andthe operating pressure selected,the load at which any systemstalls is a function of how closethe equipment is sized to theactual load and any condensateelevation or other back pressurethe trap is subject to.

Other less obvious things canalso seriously contribute to “sys-tem stall”; for instance, overlygenerous fouling factors andequipment oversizing. As anexample, a fouling factor of “only”.001 can result in a coil surfacearea increase of 50% (See Table10). Equipment oversizing causesthe system to stall faster. This isparticularly the case when theheating equipment is expected torun considerably below “designload.”

Saturated steam temperatureis directly related to its pressure

and for any load requirement, thecontrol valve output is determinedby the basic heat transfer equa-tion, Q = UA x ∆T. With “UA” for asteam-filled coil a constant, theamount of heat supplied, “Q”, isregulated by the “∆T,” the logmean temperature difference(LMTD) between the heated air orliquid and saturated steam tem-perature at the pressure deliveredby the valve. Thus, the steampressure available to operate thetrap is not constant but varies withthe demand for heat from almostline pressure down through sub-atmospheric, to completeshutdown when no heat isrequired. Actual differential acrossthe trap is further reduced whenthe heating surface is oversized orthe trap must discharge against aback pressure. Knowing theseconditions, the system must bedesigned accordingly.

Plotting A “Stall Chart”An easy way to determine theconditions at which drainage

problems will occur, and preventthem at the design stage is to usethe “stall chart” shown in Fig. 45.

The steam supply pressure isshown on the vertical axis, withcorresponding temperatures onthe opposite side, and the plot willindicate graphically what will occurfor any percentage of the designload. This method provides a fairlyaccurate prediction of stall condi-tions even though the chart uses“arithmetic” rather than “log mean”temperature difference.

SYSTEMDESIGN

Table 10:Percentage Fouling AllowanceVelocity Fouling Factor

in Ft./Sec. .0005 .0011 1.14 (14%) 1.27 (27%)

2 1.19 (19%) 1.38 (38%)

3 1.24 (24%) 1.45 (45%)

4 1.27 (27%) 1.51 (51%)

5 1.29 (29%) 1.55 (55%)

6 1.30 (30%) 1.60 (60%)

7 1.31 (31%) 1.63 (63%)

Figure 45: Stall Chart

100 90 80 70 60 50 40 30 20 10 0

400

380

360

340

320

300

280

260

240

220

200

180

160

140

120

100

80

60

40

20

0

Percentage Load

Tem

per

atu

re °

F

235

180

140

105

75

55

34

20

10

305"10"15"20"

25" Inch

es V

acu

um

P

ress

ure

psi

g

Draining Temperature Controlled Steam Equipment

34

An example plot is shown onFig. 46 for a coil where air is heat-ed to 80°F and the trap mustdischarge against back pressure.Step 1. The system is designed for100% load when air enters at 0°F(T1) and there is 0% load when airenters at 80°F (T2). Draw line(T1/T2) connecting these points.Step 2. At maximum load, thearithmetic mean air temperature(MT) is 40°F. Locate (MT) on line(T1/T2), extend horizontally to 0%load, and identify as (MT1).Step 3. Allowing for pressuredrop, the control valve has beensized to supply 25 psig steam tothe coil at 100% load. This pres-sure is (P1) and has a steamtemperature of 267°F. Mark (P1)and draw line (P1/MT1).Line (P1/MT1) approximates thesteam supply at any load condi-tion and the coil pressure is belowatmospheric when it drops belowthe heavy line at 212°F. In a grav-ity system with sub-atmospheric

conditions, a vacuum breaker andhydraulic pressure due to conden-sate will prevent stall and allowthe trap to drain the coil.Step 4. In many systems, the trapdoes not discharge freely toatmosphere and in our example,total back pressure on the trap is15 psig, drawn as horizontal dot-ted line (P2). Coil pressure equalsback pressure at the intersectionof (P2) with (P1/MT1) which whendropped vertically downward to(R1) occurs at 93% load. At lessthan this load, the required trapdifferential is eliminated, the sys-tem “stalls,” and the coil begins towaterlog. In our air heating coilthe air flows at a constant rateand extending the air temperatureintersection horizontally to (R2),stall occurs when the incoming airis 6°F or more.

The same procedure appliesto a heat exchanger although theexample temperature is not acommon one. If the stall chart

example represented a heatexchanger where the liquid was tobe heated through a constant tem-perature rise from 0 to 80°F, but ata flow rate that varies, stall wouldstill occur below 93% load. In thisinstance, if 100% load representsa 50 GPM exchanger, the systemwould stall when the demand was46.5 GPM (50 x .93) or less.

Draining Equipment Under“Stall” Conditions“System stall” is lack of positivedifferential across the steam trapand temperature controlledequipment will always be subjectto this problem when the trapmust operate against back pres-sure. Under these conditions, avacuum breaker is ineffectivebecause “stall” always occursabove atmospheric pressure.Even when steam is supplied at aconstant pressure or flow to“batch” type equipment, stall canoccur for some period of time onstartup when the steam condens-es quickly and the pressure dropsbelow the required differential.

What happens when the sys-tem stalls is that the effective coilarea (“UA” in the formula) drops asthe steam chamber floods andheat transfer is reduced until thecontrol valve responds to deliver anexcessive supply of steam to thecoil. This results in a “hunting sys-tem” with fluctuating temperaturesand hammering coils as the rela-tively cooler condensatealternately backs up, then at leastsome portion is forced through thetrap.

The solution to all system stallproblems is to make condensatedrain by gravity. Atmospheric sys-tems tend to operate morepredictably and are generally eas-ier to control but major heatingequipment is usually not drainedinto an atmospheric returnbecause of the large amount ofenergy that is lost from the vent. Inmany process plants, ventingvapors of any type is discouragedand a “closed loop” system is notonly required but is less subject tooxygen corrosion problems.

SYSTEMDESIGN

Figure 46: Air Make-up Coil Stall Chart

100 90 80 70 60 50 40 30 20 10 0

400

380

360

340

320

300

280

260

240

220

200

180

160

140

120

100

80

60

40

20

0

Percentage Load

Tem

per

atu

re °

F

235

180

140

105

75

55

34

20

10

305"10"15"20"

25"

T2

MT1

Inch

es V

acu

um

P

ress

ure

psi

g

R1

T1

R2

Des

ign

MT

D

Sta

ll M

TD

P1

P2

MT

Draining Temperature Controlled Steam Equipment

35

Closed Loop Drainage Sys-temsTo make equipment drain bygravity against back pressure, thesteam trap must be replaced by aPressure Powered Pump™ orpump/trap combination installedin a closed loop system. In thisarrangement, the equipmentdoes not have a vacuum breakerbut is pressure equalized to drainby gravity, then isolated whilecondensate is pumped from thesystem. The basic hookup isshown in Fig. II-32 (page 99)where the equipment is constant-ly stalled and back pressurealways exceeds the control valvesupply pressure.

In many closed loop applica-tions, the pump alone is notsuitable because the steam sup-ply pressure can at times exceedthe back pressure (P1 is higher onthe “Stall Chart” than P2.) Theseapplications require the PressurePowered Pump™ to be fitted inseries with a Float andThermostatic trap (combinationpump-trap) to prevent steamblowthrough at loads above thestall point.

With pressurized returns andlarger coils, it is often economicalto fit a combination pump/trap toeach coil in a closed loop systemrather than the conventional grav-ity drain line acceptingcondensate from several trapsand delivering it to a commonpump. The pump/trap system isillustrated in Fig. II-35 (page 101)with the check valve fitted afterthe trap. This hookup assuresmaximum heat from the equip-ment and provides the additionaladvantages of no atmosphericventing, no vacuum breakers,therefore less oxygen contamina-tion and no electric pump seals toleak. Integral to the design of thissystem is the air vent for startup,the liquid reservoir for accumula-tion during discharge, andconsideration should also begiven to shutdown draining with aliquid expansion steam trap.

Sizing A CombinationPump/TrapThe Pressure-Powered Pump™

selected must have capacity tohandle the condensate load fromthe equipment at the % stall con-dition. Trap sizing is more criticaland should be a high capacity

Float and Thermostatic type sizednot for the equipment load, but tohandle the high flow rate duringthe brief pump discharge period.

The trap must be capable ofhandling the full system operatingpressure with a capacity of stallload at 1/4 psig. This size trap willallow the pump to operate at itsmaximum capacity.

Multiple Parallel Coils With ACommon Control ValveWhile group trapping should gen-erally be avoided, a system with asingle control valve supplyingsteam to identical parallel coilswithin the same air stream can bedrained to a single pump/trapcombination closed loop system.(See Fig. 47.) This hookuprequires that the pressure must befree to equalize into each coil. Noreduced coil connections can bepermitted and the common con-densate manifold must not onlypitch to the pump but be largeenough to allow opposing flow ofsteam to each coil while conden-sate drains to the pump/trap. Thebasic premise still applies, thatcoils which are fully air vented andfree to drain by gravity give maxi-mum heat output.

SYSTEMDESIGN

Figure 47Combination Pressure-Powered Pump/Traps in a Closed Loop Eliminate Waterlogging in Parallel Steam CoilsPreviously Trapped to a “Stalled” Level Control System

Steam Control Inlet

High PressureDrip Traps

To Drain

Level-ControlDrain Tank

Steam Control Inlet

SteamCoils

SteamCoils

ToCondensateReturn

Steam Control Inlet Steam ControlInlet

ToCondensateReturn

SteamCoils

SteamCoils

MotiveSteam

MotiveSteam

AirVent

AirVent

AirVent

AirVent

AirVent

AirVent

Pressure Powered Pump/Trap

Reservoir

Before After

Draining Temperature Controlled Steam Equipment

36

In many cases, a fluid is heatedby passing it through a series ofheat exchangers which are allprovided with steam through acommon control valve (Fig. 48).Multiple section air heater coils or“batteries” typify such applica-tions, as also the multi-roll dryersused in laundries. While the loadon the first heater is usuallyappreciably greater than the loadon later heater sections, the pro-portion of the total load whicheach section takes is often a mat-ter of “rule of thumb” or evenconjecture.

The temperature differencebetween the steam and the enter-ing cold fluid can be designated∆t1. Similarly, the temperature dif-ference between the steam andthe outlet heated fluid can be ∆t0.The ratio between ∆t1 and ∆t0 canbe calculated, and will always beless than one, see Fig. 49 (page37)

If the chart at Figure 50 isentered on the horizontal axis atthis ratio, a vertical can be takenupwards until the curve corre-sponding with the number ofheaters or coils in use is inter-sected. A horizontal from this

SYSTEMDESIGN

Absorption chillers are important sources of cooling nec-essary for many refinery processes. A typical example isthe need to cool products (using large heat exchangers)after the stripping process in an “alky” unit. Products goingto storage are generally maintained below 100°F.

Steam is used to drive the absorption process at lowpressure, typically below 15 psig. Condensate drainagebecomes a very real concern.

In this case, steam is supplied at 12 psig to the chillerthrough an automatic control valve. Condensate systembackpressure is a constant 6-7 psig, considering the 30 ft.uphill pipe-run to the vented condensate receiver. TheRefinery Contact Engineer recognized the potential forsystem stall (having previously used the PressurePowered Pump™ to overcome other similar problems).

SolutionTwo Pressure Powered Pumps™ were installed in paral-lel, along with necessary steam traps, air vents andstrainers . The Refinery supplied the reservoir and inter-connecting piping.

Benefits• Regardless of varying steam supply pressure, consid-

ering the throttling that naturally occurs through theautomatic control valve, thorough condensate drainageis assured and cooling efficiency is maintained.

• Installation cost was much lower with the PressurePowered Pumps™ over electric pumps that were alsobeing considered. Costly water and explosion proofcontrol panels were not required.

• Pump maintenance cost is also much lower throughelimination of the need for mechanical seals and pumpmotors.

Case in Action: Absorption Chiller, Condensate Drainage

Figure 48Multiple Coil Air Heater

point given the proportion of thetotal heater load which is carriedby the first section.

Multiplying this proportion bythe total load given the conden-sate rate in this section, andenables a trap with sufficientcapacity to be selected.

If it is required to accuratelydetermine the load in the second

section, estimate the temperatureat the outlet from the first section,and regard this as the inlet tem-perature for an assembly with oneless section than before.Recalculate the ratio ts - to/ts - ti2,and re-enter the chart at thisvalue to find the proportion of theremaining load taken by the “first”of the remaining sections.

Multi-Coil Heaters

Steam Temp. ts

Air InletTemp. ti

Air OutletTemp. to

Multi-Coil Heaters

37

SYSTEMDESIGN

Figure 50Load on First Section of Multi-Coil Heater

Figure 49Temperature Distribution in Multi-Coil Heater

Paper Mills require a huge volume of air exchange. Thismeans that a great deal of air heating is necessary, partic-ularly during winter months. Air Make-Up systems are splitbetween two general applications:

a. Machine or Process Air Make-Up is supplied to t heimmediate area around the machine and, more specifi-cally, to certain areas within the machine for highertemperature heating (i.e. Pocket Ventilation or PV coils).

b. Mill Air Make-Up, which is distributed across the mill forHVAC comfort.

Either application may be accomplished with singlebanks of coils or double-preheat/reheat coils, dependingon heating requirements.

The mill experienced a chronic problem of frozen AirMake-Up coils, typically associated with condensate flood-ing and waterhammer. The 50/150 psig steam coilsballooned and ruptured routinely, creating costly mainte-nance headaches and safety hazards. Several coils wereremoved from service, requiring extensive repair.

SolutionMill Engineers, working with the local Spirax SarcoRepresentative, developed a long-range plan to redesignand retrofit the entire Air Make-Up System. Over the lasttwo years, approximately 20 Pressure PoweredPump™/float & thermostatic trap closed-loop packageshave been installed. The project will continue until theentire system is retrofitted. They have similarly retrofittedseveral shell and tube heat exchangers, improving waterheating efficiency.

Benefits• Energy savings are achieved through installation of

pressurized closed-loop packages. There is no loss toflash.

• Chemical savings are achieved because of the pressur-ized packages. Chemicals are not lost out the vent.

• Desired air heating efficiency has been achieved. Allretrofitted coils have operated properly and continuous-ly since installation. Flooding has been eliminated.

• Maintenance costs dropped dramatically with elimina-tion of condensate flooding, water-hammer andfreezing.

• Personnel safety has improved as steam/condensateleaks have been reduced.

Case in Action: Air Make-Up Coil Drainage

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

Ratio ∆to/∆tiP

rop

ort

ion

of

Lo

ad o

n F

irst

Sec

tio

n

Single Section

0.9

Two Section

Three SectionFour SectionFive Section

Inlet Temp.

ti

Outlet Temp.

to

Single Section ts

Temp.

∆ti

ti2

∆to

Steam Trap Selection

38

Steam Trap SizingSteam main drip traps shall besized with a 2 times safety factorat full differential pressure. Inmost cases, they will be 3/4” sizewith low capacity orifice or small-er unless otherwise shown on thedrawings and they shall be locat-ed every 200 feet or less. Trapsfor steam tracing shall be 1/4" to1/2" size. They shall be locatedevery 100 feet or less. Radiatortraps shall be pipe size. Freezeprotection traps shall be 1/2" to3/4" size unless otherwise noted.

Traps for equipment drainageare sized with safety factors thatreflect the differences of theHVAC and Process industries,such as variations in actualhydraulic head and material con-struction of tube bundles. Asummary of these typical recom-mendations are as follows:HVAC Industry• Non-modulating control sys-

tems have traps selected witha 2 times factor at full pres-sure differential.

• Modulating control systemswith less than 30 psig inletpressure have traps selected

for full-load at 1/2 psi pres-sure differential, provide 18 to24" drip leg for condensate todrain freely to 0 psi gravityreturn. (With drip legs lessthan 18", consult a SpiraxSarco representative.)

• Modulating control systemswith greater than 30 psig inletpressure have traps selectedwith a 3 times factor at fullpressure differential for allpreheat coils, and a 2 timesfactor for others.

Process Industry• Non-modulating control sys-

tems have traps selected witha 2 times factor at full pres-sure differential.

• Modulating controls systemswith less than 30 psig inletpressure have traps selectedfor full load at 1/2 psi pres-sure differential, provide 18 to24" drip leg for condensate todrain freely to gravity returnat 0 psi. (With drip legs lessthan 18", consult a SpiraxSarco representative.)

• Modulating control systemshave traps selected with a 3times factor at full pressuredifferential.

SYSTEMDESIGN

A full discussion of steam trapfunctions are found in the com-panion Fluid System Designvolume, “STEAM UTILIZATION.”The material covers operation ofall types of traps, along with theneed for proper air venting andtrap selection. Traps are bestselected not just on supply pres-sure and load requirements, butafter reviewing the requirementsof the application compared totrap characteristics including dis-charge temperature, air ventingcapability, response to pressureand load change, and resistanceto dirt, corrosion, waterhammerand freezing conditions.Answering these questions leadsto the selection of the mostappropriate generic type of trapand the general recommenda-tions found in Table 11 reflect this.This Selection Guide covers mosttrap uses and the recommendedtype can be expected to give sat-isfactory performance.

Condensate removal was needed from 3 polyvinyl butyralextruders at a pressure of 240 psi. Application requiredthat a consistent temperature be maintained the length ofthe extruder to provide product quality in the melt. Therewere nine sections per extruder.

The customer had used various brands of traps andtrap styles to drain the extruders. Most recently they useda competitors bimetallic trap. They were experiencinginconsistent temperatures throughout the length of theextruder because the bimetallic traps subcooled the con-densate, which then backed up into the heat transfer area.They were also experiencing high maintenance costs inrelation to these traps.

SolutionFloat & Thermostatic steam traps were recommended fordraining the extruders. This would give them immediatecondensate removal; therefore maintaining a consistanttemperature throughout the length of the extruder, provid-ing better control over product melt. Also, uponrecommendation, strainers were installed before the trapsto help keep dirt out, and cut down on maintenance cost.

Benefits• Maintained consistent temperatures with existing equip-

ment because there is no condensate in the heattransfer area.

• There is less maintenance cost due to the strainersinstalled before the traps.

Case in Action: Polyvinyl Butyral Extruders

Steam Trap Selection

39

A QUICK GUIDE TO THE SIZING OF STEAM TRAPSNeed To Know:1. The steam pressure at the trap—after any pressure drop through

control valves or equipment.

2. THE LIFT, if any, after the trap.Rule of thumb: 2 ft. = 1 psi back pressure, approximately.

3. Any other possible sources of BACK PRESSURE in thecondensate return system.e.g. A) Condensate taken to a pressurized DA. tank.

B) Local back pressure due to discharges of numerous traps close together into small sized return.

4. QUANTITY of condensate to be handled. Obtained fromA) Measurement, B) Calculation of heat load (see page 24), and C) Manufacturer’s Data

5. SAFETY FACTOR—These factors depend upon particularapplications, typical examples being as follows:

General With Temp. ControlMains Drainage x2 —Storage Heaters x2 —Space Unit Heaters x2 x3Air Heating Coils x2 x3Submerged Coils (low level drain) x2 —Submerged Coils (siphon drain) x3 —Rotating Cylinders x3 —Tracing Lines x2 —Platen Presses x2 —

Rule of thumb: Use factor of 2 on everything except Temperature Controlled Air Heater Coils and Converters, and Siphon applications.

How To UseThe difference between the steam pressure at the trap, and the totalback pressure, including that due to any lift after the trap, is theDIFFERENTIAL PRESSURE. The quantity of condensate should bemultiplied by the appropriate factor, to produce SIZING LOAD. Thetrap may now be selected using the DIFFERENTIAL PRESSURE andthe SIZING LOAD.

ExampleA trap is required to drain 22 lb/h of condensate from a 4" insulatedsteam main, which is supplying steam at 100 PSIG. There will be a liftafter the trap of 20 ft.

Supply Pressure = 100 psigLift = 20 ft = 10 psi approx.

ThereforeDifferential Pressure = 100 – 10 = 90 psi

Quantity = 22 lb/hrMains Drainage Factor = 2

Therefore Sizing Load = 44 lb/hr

A small reduced capacity Thermo-Dynamic® steam trap will easilyhandle the 44 lb/h sizing load at a differential pressure of 90 psi.

SYSTEMDESIGN

Steam Trap Selec-tion SoftwareSelecting the best type and sizesteam trap is easier today for sys-tem designers who use computersoftware programs. The SpiraxSarco “STEAM NEEDS ANALY-SIS PROGRAM” is available atwww.snapfour.com and goes astep further. SNAP not only rec-ommends and sizes the trap frominput conditions, but also speci-fies condensate return pumps,other necessary auxiliary equip-ment, and warns of systemproblems that may be encoun-tered. The SNAP program isuser-friendly, menu-driven soft-ware that accurately calculatesthe condensate load for a widerange of drip, tracing and processapplications (described both bycommon name and genericdescription.) Significant is the factthat a SNAP user has the choiceof selecting either a recommend-ed type of trap or a different typethat may be preferred for any rea-son. For all selections, a formalspecification sheet may be print-ed which contains additionalinformation.

As the USA’s leading provider of steam system solutions, Spirax Sarco recognizes that no two steam trappingsystems are identical. Because of the wide array of steam trap applications with inherently different characteristics,choosing the correct steam trap for optimum performance is difficult. Waterhammer, superheat, corrosive conden-sate, or other damaging operating characteristics dramatically affect performance of a steam trap. With over 80 yearsof experience in steam technology, Spirax Sarco is committed to helping it’s customers design, operate and maintainan efficient steam system. You have our word on it!

Steam Trap Selection Guide

40

SYSTEMDESIGN

1st Choice 2nd ChoiceFloat & Thermo- Balanced Liquid Inverted Float & Thermo- Balanced Liquid Inverted

Application Thermostatic Dynamic® Pressure Bimetallic Expansion Bucket Thermostatic Dynamic® Pressure Bimetallic Expansion Bucket

Steam Mains to 30 psig ✓ ✓

30-400 psig ✓ ✓

to 600 psig ✓ ✓

to 900 psig ✓ ✓

to 2000 psig ✓ ✓

with Superheat ✓ ✓

Separators ✓ ✓

Steam Tracers Critical ✓ ✓

Non-Critical ✓ ✓

Heating Equipment

Shell & Tube Heat Exchangers ✓ ✓

Heating Coils ✓ ✓

Unit Heaters ✓ ✓

Plate & Frame Heat Exchangers ✓ ✓

Radiators ✓

General Process Equipment

to 30 psig ✓ ✓

to 200 psig ✓ ✓

to 465 psig ✓ ✓

to 600 psig ✓

to 900 psig ✓

to 2000 psig ✓

Hospital Equipment

Autoclaves ✓ ✓

Sterilizers ✓ ✓

Fuel Oil Heating

Bulk Storage Tanks ✓ ✓

Line Heaters ✓

Tanks & Vats

Bulk Storage Tanks ✓ ✓

Process Vats ✓ ✓

Vulcanizers ✓ ✓

Evaporators ✓ ✓

Reboilers ✓ ✓

Rotating Cylinders ✓

Freeze Protection ✓

Table 11: Steam Trap Selection Guide

Flash Steam

41

The Formation of Flash SteamWhen hot condensate underpressure is released to a lowerpressure, its temperature mustvery quickly drop to the boilingpoint for the lower pressure asshown in the steam tables. Thesurplus heat is utilized by thecondensate as latent heat caus-ing some of it to re-evaporate intosteam. Commonly referred to as“flash steam”, it is in fact perfectlygood useable steam even at lowpressure.

Proportion Of Flash SteamReleasedThe amount of flash steam whicheach pound of condensate willrelease may be calculated readi-ly. Subtracting the sensible heatof the condensate at the lowerpressure from that of the conden-sate passing through the trapswill give the amount of heat avail-able from each pound to provideLatent Heat of Vaporization.Dividing this amount by the actu-al Latent Heat per pound at theLower Pressure will give the pro-portion of the condensate whichwill flash off. Multiplying by thetotal quantity of condensate beingconsidered gives the weight ofLow Pressure Steam available.

To simplify this procedure wecan use Table 12 to read off thepercentage of flash steam pro-duced by this pressure drop. Anexample would be if we had 100PSIG saturated steam/conden-sate being discharged from asteam trap to an atmospheric,gravity flow condensate returnsystem (0 psig), the flash per-centage of the condensate wouldbe 13.3% of the volume dis-charged.

Conversely, if we had 15 psigsaturated steam discharging tothe same (0 psig) atmosphericgravity flow return system, thepercentage of flash steam wouldbe only 4% by volume. Theseexamples clearly show that theamount of flash released

depends upon the differencebetween the pressures upstreamand downstream of the trap andthe corresponding temperaturesof those pressures in saturatedsteam. The higher the initial pres-sure and the lower the flashrecovery pressure, the greaterthe quantity of flash steam pro-duced.

It must be noted here that thechart is based upon saturatedsteam pressure/temperature con-ditions at the trap inlet, and thatthe condensate is discharged asrapidly as it appears at the trap.Steam traps that subcool the con-densate, such as balancedpressure thermostatic andbimetallic traps, hold condensateback in the system allowing it togive up sensible heat energy andcausing it to cool below the satu-rated steam temperature for thatpressure. Under those circum-stances, we must calculate fromthe formula above the percentageof flash steam produced, but theamount of subcooling (the con-densate temperature) must beknown before calculating.

SYSTEMDESIGN

Table 12: Percent FlashSteam

Pressure Atmosphere Flash Tank Pressurepsig 0 2 5 10 15 20 30 40 60 80 100

5 1.7 1.0 010 2.9 2.2 1.4 015 4.0 3.2 2.4 1.1 020 4.9 4.2 3.4 2.1 1.1 030 6.5 5.8 5.0 3.8 2.6 1.7 040 7.8 7.1 6.4 5.1 4.0 3.1 1.3 060 10.0 9.3 8.6 7.3 6.3 5.4 3.6 2.2 080 11.7 11.1 10.3 9.0 8.1 7.1 5.5 4.0 1.9 0

100 13.3 12.6 11.8 10.6 9.7 8.8 7.0 5.7 3.5 1.7 0125 14.8 14.2 13.4 12.2 11.3 10.3 8.6 7.4 5.2 3.4 1.8160 16.8 16.2 15.4 14.1 13.2 12.4 10.6 9.5 7.4 5.6 4.0200 18.6 18.0 17.3 16.1 15.2 14.3 12.8 11.5 9.3 7.5 5.9250 20.6 20.0 19.3 18.1 17.2 16.3 14.7 13.6 11.2 9.8 8.2300 22.7 21.8 21.1 19.9 19.0 18.2 16.7 15.4 13.4 11.8 10.1350 24.0 23.3 22.6 21.6 20.5 19.8 18.3 17.2 15.1 13.5 11.9400 25.3 24.7 24.0 22.9 22.0 21.1 19.7 18.5 16.5 15.0 13.4

Percent flash for various initial steam pressures and flash tank pressures.

Thus, if for example, 2000lb/h of condensate from a sourceat 100 psi is flashed to 10 psi, wecan say:

Sensible Heat at 100 psi = 309 Btu/lbSensible Heat at 10 psi = 208 Btu/lb

Heat Available for Flashing = 101 Btu/lbLatent Heat at 10 psi = 952 Btu/lb

Proportion Evaporated = 101 .–. 952 = 0.106 or 10.6%

Flash Steam Available = 0.106 x 2000 lb/h= 212 lb/h

Flash Steam

42

Flash Steam UtilizationIn an efficient and economicalsteam system, this so calledFlash Steam will be utilized, onany load which will make use oflow pressure steam. Sometimes itcan be simply piped into a lowpressure distribution main forgeneral use. The ideal is to havea greater demand for LowPressure steam, at all times, thanavailable supply of flash steam.Only as a last resort should flashsteam be vented to atmosphereand lost.

If the flash steam is to berecovered and utilized, it has tobe separated from the conden-sate. This is best achieved bypassing the mixture of flashsteam and condensate throughwhat is know as a “flash tank” or“flash vessel”. A typical arrange-ment is shown in Fig. II-76 (page120).The size of the vessel has tobe designed to allow for areduced velocity so that the sepa-ration of the flash steam andcondensate can be accomplishedadequately, so as not to have car-ryover of condensate out into theflash steam recovery system.This target velocity is ten feet persecond per ASHRAE standardsto ensure proper separation. Thecondensate drops to the bottomof the flash tank where it isremoved by a float and thermo-static steam trap. The flash steamoutlet connection is sized so thatthe flash steam velocity throughthe outlet is approximately 50ft./sec. The condensate inlet isalso sized for 50 ft./sec. flashvelocity.

A number of basic require-ments and considerations have tobe met before flash steam recov-ery is a viable and economicalproposition:1. It is first essential to have a

sufficient supply of conden-sate, from loads at sufficientlyhigher pressures, to ensurethat enough flash steam willbe released to make recoveryeconomically effective.

The steam traps, and theequipment from which theyare draining condensate,must be able to function sat-isfactorily while accepting thenew back pressure applied tothem by the flash recoverysystem. Particular care isneeded when attempting torecover flash steam fromcondensate which is leavingequipment controlled by amodulating temperature con-trol valve. At less than fullloads, the steam space pres-sure will be lowered by theaction of the temperaturecontrol valve. If the steamspace pressure approachesor even falls below the flashsteam vessel pressure, con-densate drainage from thesteam space becomesimpractical by a steam trapalone, and the equipmentbecomes “stalled” and waterlogging will most definitelyoccur.

2. The second requirement is asuitable use for low pressureflash steam. Ideally, low pres-sure load(s) requires at alltimes a supply of steamwhich either equals orexceeds the available flashsteam supply. The deficit canthen be made up through apressure reducing valve set.If the supply of flash steamexceeds the demand for it,the surplus may have to bevented to waste through abackpressure control valve(see Fig. II-77, page 120).Thus, it is possible to utilizethe flash steam from processcondensate on a space heat-ing installation - but thesavings will only be achievedduring the heating season.When heating is not required,the recovery systembecomes ineffective.Whenever possible, the bet-ter arrangement is to useflash steam from processcondensate to supply

process loads, and that fromheating condensate to supplyheating loads. Supply anddemand are then more likelyto remain “in step”. When allelse fails, in many facilitiesthere is always a need for hotwater, especially in the boilerhouse. This can be suppliedvia a heat exchanger and theuse of flash steam.

3. It is also preferable to selectan application for the flashsteam which is reasonablyclose in proximity to the highpressure condensate source.Piping for low pressure steamis inevitably of largerdiameter. This makes itsomewhat costly to install.Furthermore, the heat lossfrom large diameter pipesreduces the benefits obtainedfrom flash steam recoveryand in the worst cases couldoutweigh them.Flash steam recovery is sim-

plest when being recovered froma single piece of equipment thatcondenses a large amount ofsteam, such as a large steam towater converter of a large air han-dling coil bank, but we cannotforget that flash steam recoverysystems by design will apply abackpressure to the equipmentbeing utilized as the flash steamsource.

How To Size Flash TanksAnd Vent LinesWhether a flash tank is atmos-pheric or pressurized for flashrecovery, the procedure for deter-mining its size is the same. Themost important dimension is thediameter. It must be large enoughto provide adequate separation ofthe flash and condensate to mini-mize condensate carryover.

SYSTEMDESIGN

Flash Steam

43

ExampleSize a 20 psig flash recovery ves-sel utilizing condensate from a160 psig steam trap discharging3000 lb/h.1. Determine percent flash

steam produced using Table12. With a steam pressure of160 psig and a flash tankpressure of 20 psig, read avalue of 12.4%.

2. Next, multiply the condensateload by the percent flash fromStep #1 to determine the

flowrate, of flash steam pro-duced. 3,000 lb/h x .124 =372 lb/h.

3. Using the calculated flashsteam quantity of 372 lb/henter Fig. 51 at “A” and movehorizontally to the right to theflash tank pressure of 20 psig“B”. Rise vertically to the flashtank diameter line (600ft/min) at “D”. Read tankdiameter of 5”. If schedule 80pipe is to be installed, thetable within the body of the

chart can be used to deter-mine whether the velocity willexceed the recommendedlimit of 600 ft/min.

4. From point “D” continue torise vertically to “E” to deter-mine the size of vent pipe togive a velocity between 3000and 4000 ft/min. In this case2” schedule 40 pipe. Asbefore, use the table withinthe body of chart for schedule80 pipe.

SYSTEMDESIGN

6000

3000

4000

2000

1000

600

100

66

50

33

50,000

30,000

20,000

10,000

8000

20

30

40

5060

80

100

200

300

500

8001000

2000

3000

5000

Fla

sh S

team

Flo

wra

te (

lb/h

)

Velocity(ft/sec)

Velocity(ft/min)

Pressure in

condensate line or

flash tank (psig)

Pipe Size (schedule 40)

A

D

E

C

RecommendedService

Condensate ReturnLine Sizing

Vent Pipe Sizing

Flash TankDiameter Sizing

10

17

28"30"24"

26"20"

18"16"

14"12" 10" 8" 6" 5" 4" 3"

2-1/2"2"

1-1/2"1-1/4"

1" 3/4"1/2"

B

1008060403020

1050

1008060403020

1050

1008060403020

1050

Multiply chart velocityby factor belowto get velocity

in schedule 80 pipe

Pipe Size1/2"3/4" & 1"1-1/4" & 1-1/2"2" & 3"4" to 24"26" to 30"

Factor1.301.231.151.121.11.0

10

Figure 51: Condensate Line, Flash Tank, and Vent Line Sizing

Flash Steam

44

SYSTEMDESIGN

Condensateinlet

Flash Steamoutlet or vent pipe

DiameterLength

Condensateoutlet

Length = 2 x diameter or24" minimum

For proper installation of flash vessels, controls and traps refer toFigures II-76, 77, 78, 79, 80, 81, 82, 83 (starting on page 120)

HorizontalFlash Vessel

Vertical FlashVessel

Figure 52: Flash Vessel Configurations

Diameter

35% ofheight

Condensateinlet

Condensateoutlet

Height = 3 x Diameter or36" minimum

Flash steam outletor vent pipe

The sour water condenser-reboiler is an important ele-ment in a refinery sulfur unit. Though theconfiguration/design will vary with the specific processused, the purpose and priority remain the same. Processwater contaminated with ammonia and hydrogen sulfidegas (H2S) is stripped of those compounds for reuse. Theremaining stream of contaminants goes to waste treat-ment. The process depends on accurate temperaturecontrol of the steam heated condenser-reboiler.

40 psig steam is supplied through a modulating con-trol valve. Condensate is lifted 15 feet from the outlet at thebottom of the vertical condenser-reboiler to the overheadcondensate receiver tank, which is maintained at 20 psig.Process load fluctuations and resultant turndown on themodulating steam control valve would have created aSTALL situation, unacceptable process temperature con-trol and reduced throughput.

SolutionA 3" x 2" PPF with 2-1/2" FTB 125 pump/trap combinationwas designed into the new project as was a VS 204 airvent. The installation was immediately successful.

Benefits• With faster start-up, it came up to temperature faster

than any other comparable unit, to date, at the refinery.This improves productivity.

• The feed rate is higher than designed because the unitis able to operate efficiently at any degree of turndown.

• Installation cost is several times less costly for thepump/trap combo than traditional level control systemthat would otherwise have been used.

• Maintenance cost is lower, through elimination of elec-tric/pneumatic controls and electric pumps used in atraditional level control system.

Case in Action: Sour Water Condenser-Reboiler Temperature Control

Flash Vessel ConfigurationsFlash vessels can be either horizontal or vertical. For flash steam recovery (pressurized receiver) the verticalstyle is preferred because of its ability to provide better separation of steam and water.

Condensate Recovery Systems

45

The importance of effective con-densate removal from steamspaces has been stressedthroughout this course. If maxi-mum steam system efficiency isto be achieved, the best type ofsteam trap must be fitted in themost suitable position for theapplication in question, the flashsteam should be utilized, and themaximum amount of condensateshould be recovered.

There are a number of rea-sons why condensate should notbe allowed to discharge to drain.The most important considerationis the valuable heat which it con-tains even after flash steam hasbeen recovered. It is possible touse condensate as hot processwater but the best arrangement isto return it to the boiler house,where it can be re-used as boilerfeed water without further treat-ment, saving preheating fuel, rawwater and the chemicals neededfor boiler feed treatment. Thesesavings will be even greater incases where effluent chargeshave to be paid for the dischargeof valuable hot condensate downthe drain.

Condensate recovery sav-ings can add up to 20 to 25% ofthe plant’s steam generatingcosts. One justifiable reason fornot returning condensate is therisk of contamination. Perforatedcoils in process vessels and heatexchangers do exist and thecross contamination of conden-sate and process fluids is alwaysa danger. If there is any possibili-ty that the condensate iscontaminated, it must not bereturned to the boiler. Theseproblems have been lessened bythe application of sensing sys-tems monitoring the quality ofcondensate in different holdingareas of a plant to determine con-densate quality and providing ameans to re-route the conden-sate if contaminated.

Condensate Line SizingCondensate recovery systemsdivide naturally into three sec-tions, each section requiringdifferent design considerations.a. Drain Lines to the traps carry

pressurized high temperaturehot water that moves by grav-ity.

b. Trap discharge lines thatcarry a two-phase mixture offlash steam and condensate.

c. Pumped return systems uti-lizing electric or non-electricpumps.

Drain Lines To TrapsIn the first section, the conden-sate has to flow from thecondensing surface to the steamtrap. In most cases this meansthat gravity is relied on to induceflow, since the heat exchangersteam space and the traps are atthe same pressure. The linesbetween the drainage points andthe traps can be laid with a slightfall, say 1” in 10 feet, and Table 13shows the water carrying capaci-ties of the pipes with such agradient. It is important to allowfor the passage of incondensiblesto the trap, and for the extra waterto be carried at cold starts. Inmost cases, it is sufficient to sizethese pipes on twice the full run-ning load.

Trap Discharge LinesAt the outlet of steam traps, thecondensate return lines mustcarry condensate, non-condensi-ble gases and flash steamreleased from the condensate.Where possible, these linesshould drain by gravity to the con-densate receiver, whether this bea flash recovery vessel or thevented receiver of a pump. Whensizing return lines, two importantpractical points must be consid-ered.

First, one pound of steamhas a specific volume of 26.8cubic feet at atmospheric pres-sure. It also contains 970 BTU’sof latent heat energy. This meansthat if a trap discharges 100pounds per hour of condensatefrom 100 psig to atmosphere, theweight of flash steam releasedwill be 13.3 pounds per hour, hav-ing a total volume of 356.4 cubicfeet. It will also have 12,901BTU’s of latent heat energy. Thiswill appear to be a very largequantity of steam and may welllead to the erroneous conclusionthat the trap is passing live steam(failed open).

Another factor to be consid-ered is that we have just released13.3 pounds of water to theatmosphere that should havegone back to the boiler house forrecycling as boiler feed water.Since we just wasted it, we nowhave to supply 13.3 pounds offresh city water that has beensoftened, chemically treated andpreheated to the feedwater sys-tem’s temperature before puttingthis new water back into the boil-er.

Secondly, the actual forma-tion of flash steam takes placewithin and downstream of thesteam trap orifice where pressuredrop occurs. From this pointonward, the condensate returnsystem must be capable of carry-ing this flash steam, as well ascondensate. Unfortunately, in thepast, condensate return lines

SYSTEMDESIGN

Table 13: Condensate, lb/hSteel Approximate Frictional ResistancePipe in inches Wg per 100 ft of TravelSize 1 5 7 101/2" 100 240 290 3503/4" 230 560 680 8201" 440 1070 1200 155011/4" 950 2300 2700 330011/2" 1400 3500 4200 50002" 2800 6800 8100 990021/2" 5700 13800 16500 200003" 9000 21500 25800 310004" 18600 44000 52000 63400

Condensate Recovery Systems

46

have been sized using water vol-ume only and did not include theflash steam volume that is pre-sent.

The specific volume of waterat 0 psig is .017 cubic feet perpound, compared to 26.8 cubicfeet per pound for flash steam atthe same pressure. Sizing of con-densate return lines from trapdischarges based totally on wateris a gross error and causes linesto be drastically undersized forthe flash steam. This causes con-densate lines to becomepressurized, not atmospheric,which in turn causes a backpres-sure to be applied to the trap’sdischarge which can causeequipment failure and flooding.

This undersizing explainswhy the majority of 0 psi atmos-pheric condensate returnsystems in the United States donot operate at 0 psig. To take thisthought one step further for thosepeople who perform temperaturetests on steam traps to determineif the trap has failed, the instantwe cause a positive pressure todevelop in the condensate returnsystem by flash steam, the con-densate return line now mustfollow the pressure/temperaturerelationship of saturated steam.So, trap testing by temperatureidentifies only that we have areturn system at a certain tem-perature above 212°F (0 psig)and we can then determine bythat temperature the systempressure at which it is operating.Elevated condensate return tem-peratures do not necessarilymean a trap has failed.

When sizing condensatereturn lines, the volume of theflash steam must be given dueconsideration. The chart at Fig.51 (page 43) allows the lines tobe sized as flash steam lines—since the volume of thecondensate is so much less thanthat of the steam released.

Draining condensate from

traps serving loads at differingpressures to a common conden-sate return line is a conceptwhich many find difficult. It isoften assumed that the HP “highpressure” condensate will preventthe “low pressure” condensatefrom passing through the LPtraps and give rise to waterlog-ging of the LP system.

However, the terms HP andLP can only apply to the condi-tions on the upstream side of theseats in the traps. At the down-stream or outlet side of the traps,the pressure must be the com-mon pressure in the return line.This return line pressure will bethe sum of at least three compo-nents:1. The pressure at the end of

the return line, either atmos-pheric or of the vessel intowhich the line discharges.

2. The hydrostatic head neededto lift the condensate up anyrisers in the line.

3. The pressure drop needed tocarry the condensate andany flash steam along theline.Item 3 is the only one likely to

give rise to any problems if con-densate from sources at differentpressures enters a common line.The return should be sufficientlylarge to carry all the liquid con-densate and the varying amountsof flash steam associated with it,without requiring excessive linevelocity and excessive pressuredrop. If this is accepted, the totalreturn line cross sectional areawill be the same, whether a singleline is used, or if two or more linesare fitted, with each taking thecondensate from a single pres-sure source.

The return could becomeundersized, requiring a high pres-sure at the trap discharges andrestricting or preventing dis-charge from the LP traps, if it isforgotten that the pipe has to

carry flash steam as well as waterand that flash steam is releasedin appreciable quantity from HPcondensate.

While the percentage, byweight, of flash steam may berather low, its overall volume incomparison to the liquid is verylarge. By determining the quantityof flash steam and sizing thereturn line for velocities between4,000 and 6,000 ft/min, the two-phase flow within the pipe can beaccommodated. The informationrequired for sizing is the conden-sate load in lb/h, inlet pressure tosteam trap(s) in psig and returnline system pressure.Example:Size a condensate return linefrom a 160 psig steam trap dis-charging to 20 psig. flash tank.Load is 3,000 lb/h.1. Determine percent flash

steam produced using Table12 (page 41). With a steampressure of 160 psig and aflash tank pressure of 20 psigread a value of 12.4%.

2. Next, multiply the condensateload by the percent flash fromstep #1 to determine theflowrate, of flash steam pro-duced.3,000 lb/h x .124 = 372 lb/h.

3. Enter Fig. 51 (page 43) at theflash steam flowrate of 372lb/h at “A” and move horizon-tally to the right to the flashtank pressure of 20 psig “B”.Rise vertically to choose acondensate return line sizewhich will give a velocitybetween 4,000 and 6,000ft/min, “C”. In this example, an1-1/2” schedule 40 pipe witha velocity of approximately5,000 ft/min. If schedule 80pipe is to be used, refer totable within body of chart.Multiply the velocity by thefactor to determine whetherthe velocity is within accept-able limits.

SYSTEMDESIGN

Condensate Recovery Systems

47

Pumped Return LinesFinally, the condensate is oftenpumped from the receiver to theboiler plant. These pumped con-densate lines carry only water,and rather higher water velocitiescan often be used so as to mini-mize pipe sizes. The extra frictionlosses entailed must not increaseback pressures to the point wherethe pump capacity is affected.Table 35 (page 77) can be usedto help estimate the frictionalresistance presented by thepipes. Commonly, velocities inpumped returns should be limitedto 6-8 ft./sec.

Electric pumps are common-ly installed with pumpingcapability of 2-1/2 or 3 times therate at which condensate reachesthe receiver. This increasedinstantaneous flow rate must bekept in mind when sizing thedelivery lines. Similar considera-tions apply when steam poweredpumps are used, or appropriatesteps taken to help attain con-stant flow along as much aspossible of the system.

Where long delivery lines areused, the water flowing along thepipe as the pump dischargesattains a considerable momen-tum. At the end of the dischargecycle when the pump stops, thewater tends to keep moving alongthe pipe and may pull air or steaminto the delivery pipe through thepump outlet check valve. Whenthis bubble of steam reaches acooler zone and condenses, thewater in the pipe is pulled backtowards the pump. As thereversed flow reaches and closesthe check valve, waterhammeroften results. This problem isgreatly reduced by adding a sec-ond check valve in the deliveryline some 15 or 20 ft. from thepump. If the line lifts to a highlevel as soon as it leaves thepump, then adding a generouslysized vacuum breaker at the top

of the riser is often an extra help.However, it may be necessary toprovide means of venting fromthe pipe at appropriate points, theair which enters through the vac-uum breaker. See Figures II-71and II-72 (page 118).

The practice of connectingadditional trap discharge linesinto the pumped main is to beavoided whenever possible. Theflash steam which is releasedfrom this extra condensate leadsto thermal shock creating a bang-ing noise within the pipingcommonly associated with water-hammer. The traps shoulddischarge into a separate gravity

line which carries the condensateto the receiver of the pump. If thisis impossible, a second bestalternative may be to pipe thetrap discharge through a spargeor diffuser inside the pumpedreturn line.

The trap most suitable for thisapplication would be the Floatand Thermostatic type due to itscontinuous discharge.This is verymuch a compromise and will notalways avoid the noise (see Fig.53 and 53A) although it willreduce the severity.

SYSTEMDESIGN

Figure 53Discharge of Steam Trap into Pumped (flooded) Return Line usingSparge Pipe.

CondensateReturn

Dischargefrom Trap

Figure 53ADischarge of Steam Trap into Pumped (flooded) Return Lineusing a Trap Diffuser.

Spira-tecLoss Detector

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Trap Diffuser

Condensate Pumping

48

In nearly all steam-using plants,condensate must be pumpedfrom the location where it isformed back to the boilerhouse,or in those cases where gravitydrainage to the boilerhouse ispractical, the condensate must belifted into a boiler feed tank ordeaerator. Even where deaera-tors are at low level, they usuallyoperate at a pressure a few psiabove atmospheric and again, apump is needed to lift condensatefrom atmospheric pressure todeaerator tank pressure.

Electric CondensateReturn PumpsWhen using electric pumps to liftthe condensate, packaged unitscomprising a receiver tank (usu-ally vented to atmosphere) andone or more motorized pumpsare commonly used. It is impor-tant with these units to make surethat the maximum condensatetemperature specified by themanufacturer is not exceeded,and the pump has sufficientcapacity to handle the load.Condensate temperature usuallypresents no problem with returnsfrom low pressure heating sys-tems. There, the condensate isoften below 212°F as it passesthrough the traps, and a little fur-ther subcooling in the gravityreturn lines and in the pumpreceiver itself means that there islittle difficulty in meeting the max-imum temperature limitation. SeeFig. II-74 (page 119).

On high pressure systems,the gravity return lines often con-tain condensate at just above212°F, together with some flashsteam. The cooling effect of thepiping is limited to condensing alittle of the flash steam, with theremainder passing through thevent at the pump receiver. Thewater must remain in the receiverfor an appreciable time if it is tocool sufficiently, or the pump dis-charge may have to be throttleddown to reduce the pump’s capac-ity if cavitation is to be avoided.See Fig. II-75 (page 119).

The absolute pressure at theinlet to the pump is usually theatmospheric pressure in thereceiver, plus the static head fromthe water surface to the pumpinlet, minus the friction lossthrough pipes, valves and fittingsbetween the receiver and thepump. If this absolute pressureexceeds the vapor pressure ofwater at the temperature at whichit enters the pump, then a NetPositive Suction Head exists.Providing this NPSH is above thevalue specified by the pump man-ufacturer, the water does notbegin to boil as it enters the pumpsuction, and cavitation is avoided.If the water entering the pump isat high temperature, its vaporpressure is increased and agreater hydrostatic head over thepump suction is needed to ensurethat the necessary NPSH isobtained.

If the water does begin to boilin the pump suction, the bubblesof steam are carried with thewater to a high pressure zone inthe pump. The bubbles thenimplode with hammer-like blows,eroding the pump and eventuallydestroying it. The phenomenon iscalled cavitation and is readilyrecognized by its typical rattle-likenoise, which usually diminishesas a valve at the pump outlet isclosed down.

However, since in most casespumps are supplied coupled toreceivers and the static head

above the pump inlet is alreadyfixed by the pump manufacturer, itis only necessary to ensure thatthe pump set has sufficientcapacity at the water temperatureexpected at the pump. Pumpmanufacturers usually have a setof capacity curves for the pumpwhen handling water at differenttemperatures and these shouldbe consulted.

Where steam systems oper-ate at higher pressures thanthose used in LP space heatingsystems, as in process work, con-densate temperatures are often212°F, or more where positivepressures exist in return lines.Electric pumps are then usedonly if their capacity is downratedby partial closure of a valve at theoutlet; by using a receiver mount-ed well above the pump to ensuresufficient NPSH; or by subcoolingthe condensate through a heatexchanger of some type.

Pressure Powered Conden-sate PumpAll these difficulties are avoidedby the use of non-electric con-densate pumps, such as thePressure Powered Pump™. ThePressure Powered Pump™ isessentially an alternating receiverwhich can be pressurized, usingsteam, air or other gas. The gaspressure displaces the conden-sate (which can be at anytemperature up to and includingboiling point) through a check

SYSTEMDESIGN

The PUMP NPSH in any given application can readily be estimatedfrom:

NPSH = hsv = 144 (Pa - Pvp) + hs - hfW

Where:Pa = Absolute pressure in

receiver supplying pump,in psi (that is at atmos-pheric pressure in thecase of a vented receiver).

Pvp= Absolute pressure ofcondensate at the liquidtemperature, in psi.

hs = Total suction head in feet.(Positive for a head abovethe pump or negative for alift to the pump)

hf = Friction loss in suction piping.W = Density of water in pounds

per cubic foot at theappropriate temperature.

Condensate Pumping

49

valve at the outlet of the pumpbody. At the end of the dischargestroke, an internal mechanismchanges over, closing the pres-surizing inlet valve and openingan exhaust valve. The pressuriz-ing gas is then vented toatmosphere, or to the space fromwhich the condensate is beingdrained. When the pressures areequalized, condensate can flowby gravity into the pump body torefill it and complete the cycle.

As the pump fills by gravityonly, there can be no cavitationand this pump readily handlesboiling water or other liquids com-patible with its materials ofconstruction.

The capacity of the pumpdepends on the filling head avail-able, the size of the condensateconnections, the pressure of theoperating steam or gas, and thetotal head through which the con-densate is lifted. This will includethe net difference in elevationbetween the pump and the finaldischarge point; any pressure dif-ference between the pumpreceiver and final receiver; frictionin the connecting pipework, andthe force necessary to acceleratethe condensate from rest in thepump body up to velocity in thedischarge pipe. Tables listingcapacities under varying condi-tions are provided in the catalogbulletins.

Piping RequirementsDepending upon the application,the Pressure Powered Pump™

body is piped so that it is ventedto atmosphere or, in a closed sys-tem, is pressure equalized backto the space that it drains. Thisallows condensate to enter thepump but during the short dis-charge stroke, the inlet checkvalve is closed and condensateaccumulates in the inlet piping. Toeliminate the possibility of con-densate backing up into thesteam space, reservoir pipingmust be provided above thepump with volume as specified in

the catalog. A closed systemrequires only a liquid reservoir. Inopen systems, the vented receiv-er serves this purpose as it isalways larger in order to also sep-arate the flash steam released.

Vented SystemsCondensate from low pressureheating systems may be pipeddirectly to a small size PressurePowered Pump™ only when 50lb/h or less of flash steam mustvent through the pump body. Thisdoes not eliminate the require-ment that there must be enoughpiping to store condensate duringthe brief discharge cycle. In manylow pressure systems, the reser-voir may be a section of largerhorizontal pipe which is vented toeliminate flash steam. In higherpressure, high load systems, thelarger quantity of flash releasedrequires a vented receiver withpiping adequate to permit com-plete separation. To preventcarryover of condensate from the

vent line, the receiver should besized to reduce flow velocity toabout 10 FPS.

Closed Loop SystemsIt is often advisable where largercondensate loads are being han-dled to dedicate a PressurePowered Pump™ to drain a singlepiece of equipment. The pumpexhaust line can then be directlyconnected to the steam space ofa heat exchanger or, preferablywith air heating coils, to the reser-voir. This allows condensate todrain freely to the pump inlet andthrough a steam trap at the pumpoutlet. Only liquid is contained inthe reservoir of a closed loop sys-tem. Fig.II-32 (page 99) illustrateshow the Pressure-Powered pumpfunctions as a pumping trap, anduse Fig. II-35 (page 101) whenthe steam supply may sometimesbe greater than the return pres-sure and a combinationpump/trap is required.

SYSTEMDESIGN

Figure 54Venting of Pump Exhaust and Inlet Receiver Pipe in aLow Pressure System

CondensateReturn

SteamSupply

PressurePowered

Pump

Vented Receiver

Vent

Clean Steam

50

Clean SteamThe term “Clean Steam” cancover a wide range of steam qual-ities, depending on theproduction method used and thequality of the raw water.

The term “Clean Steam” issomething of a misnomer and iscommonly used as a blanketdescription to cover the threebasic types - filtered steam, cleansteam and pure steam.a) Filtered steam is produced by

filtering plant steam using ahigh efficiency filter. A typicalspecification would call for

the removal of all particlesgreater than 2.8 microns,including solids and liquiddroplets (Fig. 55).

b) Clean steam is raised in asteam generator or takenfrom an outlet on a multi-effect still, and is oftenproduced from deionized ordistilled water. A simpliffiedgenerator and distributionsystem is shown in Fig. 56.

c) Pure steam is very similar toclean steam, but is alwaysproduced from distilled,deionized or pyrogen-free

water, and is normallydefined as “uncondensedwater for injection (WFI)”.Often, the generic term “clean

steam” is used to describe any ofthe three different types outlinedabove. It is therefore very impor-tant to know which is being usedfor any application, as the charac-teristics and system requirementsfor each can differ greatly. Notethat in the following text, theexpression “clean” steam will beused to denote any or all of thethree basic types, where no differ-entiation is required.

SYSTEMDESIGN

Printing mills frequently mix tolulene and isopropyl acetatewith dyes to produce “quick drying” inks. This flammablemixture requires special care to avoid explosions and fire.Larger printing mills typically use steam-heated rolls to drythe printed material. The electric motor-driven condensatepumps that are commonly used, require explosion-proofcontrols/enclosures to accommodate the flammableatmosphere.

During a new project design, the consulting Engineerand Client decided to find a better way to deal with thehazardous environment and costly explosion-proof con-densate pumps. The cost was of particular concernconsidering that the project included 16 dryer rolls on 2printing machines, requiring 4 condensate pumps.

SolutionFour non-electric Pressure Powered Pumps™ were select-ed as alternatives to costlier electric pump sets. Thesewere in addition to the 16 float and thermostatic steamtraps installed on each dryer roll.

Benefits• Installation cost was lower for the Pressure Powered

Pumps™—no electrical wiring/controls required.• Pressure Powered Pumps™ purchase price was sub-

stantially lower.• Pressure Powered Pumps™ operation is safer than with

electric pump/controls.• Without mechanical seals, the Pressure Powered

Pumps™ will operate with lower maintenance cost.

Case in Action: Printing Mill Dryer Roll Drainage

Figure 55Filtered Steam: A filtered steam station produces steam to be usedfor direct injection into food products, culinary steam, or for use insterilizers and autoclaves.

Separator

SampleCooler

PressureReducing

Valve

Filter

FilteredSteam

Clean Steam

51

Steam Qualityvs. Steam PurityIt is important to define the differ-ence between steam quality andpurity.Steam Quality— “The ratio of theweight of dry steam to the weightof dry saturated steam andentrained water. For example, ifthe quality of the steam has beendetermined to be 95%, the wet-steam mixture delivered from theboiler is composed of 5 parts byweight of water, usually in theform of a fine mist, and 95 partsby weight of dry saturated steam.Likewise, if the quality of thesteam has been determined to be100%, there is no wet steamdelivered from the boiler, 100% ofthe steam delivered from the boil-er is dry saturated steam.”Steam Purity— “A quantitativemeasure of contamination ofsteam caused by dissolved solids,volatiles, or particles in vapour orby tiny droplets that may remain inthe steam following primary sepa-ration in the boiler”.

Thus, the three differenttypes of “clean” steam (filtered,clean and pure) can, and will,have different characteristics,summarized in Table 14.Note in particular that:1. The quality of filtered steam

will normally be high becausewater droplets larger than thefilter element rating will beremoved. Clean and puresteam systems will have aquality related to the designand operating characteristicsof the generator, length andinstallation details of distribu-tion system, insulation ofsystem, number and effec-tiveness of mains, drainagepoints, etc.

2. Boiler additives may well bepresent in filtered steam andalso possibly in clean steam,but often this will be limited byprocess requirements. Forexample, the FDA restrictsthe use of certain additives,including amines, in anysteam which comes intodirect contact with foods ordairy products.

3. Assuming the generating anddistribution system havebeen designed and installedcorrectly, the particles pre-sent in a pure steam systemwill be water only. Dependenton feed water type, the samemay also apply to cleansteam systems.

SYSTEMDESIGN

Figure 56Clean/Pure Steam Generator and Distribution System

Table 14: Differences in Steam CharacteristicsQuality Purity

Particles Boiler Additives

Filtered High Typically 2.8 microns Normally present

Clean Varies on System Design Varies Limited to process

Pure Varies on System Design Varies None

Condensate

DiaphragmValves

ProcessVessel

Condensate

Condensate

Condensate

PlantSteam

Clean SteamDistribution Main

Pure/CleanSteam

Generator

Pure Water

Main driptraps for

distributionsystem

condensateremoval

Process steam traps foreffective contaminatedcondensate drainage.

Hygienic ball valvesfor isolation on

distribution systems.

Regulatorsfor accurate

pressure control

Separators andfilters for efficient

conditioning ofsteam.

Clean Steam

52

Overall Requirements of a“Clean” Steam SystemThe overall requirements of a“clean” steam system, irrespec-tive of the means of generation ofproduction used, can be very sim-ply stated:

It is essential that thesteam delivered to the point ofuse is of the correct qualityand purity for the process.

In order to achieve this endgoal, there are three key areas ofdesign which must be consideredonce the requirement for cleansteam has been identified.• Point of Use• Distribution• Production

Design and operation ofequipment, piping, components,etc. in all these three areas willinfluence the quality of the finalprocess or products. It is essen-tial for the needs of the userprocess to be the first concern.Must the steam be pyrogen free?Are any boiler additives allowed?Are products of corrosion going toharm the process or product?Must the risk of biological conta-mination be totally prevented? Itis by answering these questions,and perhaps others, which willindicate the required type of pro-duction, design of the distributionsystem, and the operation modesof the user equipment, includingaspects such as steam trapping.

Specific Requirements of“Clean” Steam SystemsClean or pure steam producedfrom water of very high purity ishighly corrosive or “ion hungry”.The corrosive nature becomesmore pronounced as the concen-tration of dissolved ions decreaseswith the resistivity approaching thetheoretical maximum of 18.25megohm/cm at 25°C. In order torecover a more natural ionic bal-ance, it will attack many of thematerials commonly used inpipework systems. To combat this,pipework, fittings, valves andassociated equipment such astraps, must be constructed from

corrosion resistant materials.Typically, a “clean” steam systemof this type will have resistivity val-ues of the condensate in the 2-15megohm/cm range, resulting invery rapid attack of inferior qualitycomponents.

Even in some filtered plantsteam applications, such as in thefood, dairy and pharmaceuticalsindustries, certain corrosion inhibit-ing chemicals may be prohibitedfrom the boiler and steam generat-ing system. Again, condensate isthen likely to be very aggressiveand so careful consideration mustbe given to material selection.

A common problem encoun-tered on clean and pure steamsystems in the pharmaceuticalindustry is that of “rouging”, whichis a fine rusting of pipes and sys-tem components. This isencountered most frequentlywhen low grade stainless steelsare used, and further corrosiondue to galvanic effects can takeplace where dissimilar alloys arepresent in the same system.Unless care is taken with materi-al selection throughout thesystem, corrosion can become amajor problem in terms of:a) Contaminating the system

with products of corrosion,which are undesirable oreven potentially dangerous tothe process or product.

b) Severely reduce life of sys-tem components, increasingmaintenance time, materialreplacement costs, and sys-tem downtime.In order to prevent these

problems, austenitic stainlesssteel should be used throughout,never of lower grade than AISI304. For severe duties, the rec-ommended material is AISI 316or 3161L (alternatively 316Ti) orbetter, passivated to furtherenhance corrosion resistance.

In summary, 316 or 316Lstainless steel is essential inpure steam systems from its pro-duction at the generator rightthrough to the steam traps. Notonly will inferior materials corrodeand fail prematurely, they will also

lead to contamination of the sys-tem as a whole. Note thatalthough filtered plant steam willnot necessarily be so aggressiveby nature, the exclusion of manyof the corrosion inhibiting feedchemicals for end product purityreasons will still demand the useof austenitic stainless steel, neverof lower grade than 304/304L, butpreferable 316/316L.

Clean Steam and CondensateSystem Design The proper and effective drainageof condensate from any steamsystem is good engineering prac-tice, as it reduces corrosion,erosion, and waterhammer, andincreases heat transfer. Thisbecomes even more important in“clean” steam system, wherepoor condensate drainage in thedistribution system or at the userequipment can result in rapid cor-rosion and also, under certainconditions, the risk of biologicalcontamination. The followingpoints should be carefully consid-ered:• Pipework should have a fall in

the direction of flow of at least1.0 inch in 10 ft., and should beproperly supported to preventsagging.

• Adequate mains and servicepipe steam trapping should beprovided, for example at all ver-tical risers, upstream of controlvalves, and at convenientpoints along any extended pipelength. Trapped drain pointsshould be provided at intervalsof at least every 100 ft.

• Undrained collecting pointsshould not be used, as dirtshould not be present and theyprovide an ideal location forbacterial growth where systemsare shut down.

• Condensate should be allowedto discharge freely from steamtraps using gravity and an airbreak. This air break should beprovided at the manifold outlet orthe closest convenient location(Fig. 57). Where the air breakwould otherwise be in a cleanroom, the potentially harmful

SYSTEMDESIGN

Clean Steam

53

effects of flash steam can be pre-vented by using an expansionpot at the end of the manifold andventing through a filtered ventoutside the clean room. The ventfilter could alternatively be locat-ed at a kill tank, if used (Fig. 58).

• To prevent the risk of contami-nation, the direct connection of“clean” steam and condensateservices should be preventedwherever possible. Under nocircumstances should the con-densate line or manifold liftabove the level of the traps.

• Where the risk of biological con-tamination must be minimized,then care should be taken toselect pipeline products whichare self draining. This becomesmost important in applicationswhere the steam supply is fre-quently turned off, and wheresteam pipeline products areclose coupled to sanitaryprocess lines. Under these con-ditions, microbial growth willbecome possible in any pocketof condensate or process fluidretained in the system. However,where the steam supply is guar-anteed, then this requirementdoes not become so stringent.

• Never “group trap” i.e. alwaysuse a single trap for drainingeach process line, vessel, etc.Failure to do this will invariablycause back-up of condensatein the system.

• The presence of crevices onpipe and component walls canprovide an ideal location formicrobial growth. Pipeline com-ponents which are likely tobecome fouled, such as steamtraps installed on process sys-tems, should be installed sothey can be easily taken out ofservice for thorough cleaning.

• A “clean” steam service shouldnot be interconnected to anyother service which is not ofsanitary design.

• Condensate from clean or puresteam systems should not bereused as make up for theclean/pure steam generationplant.

• Dead legs of piping which arenot open to steam under normaloperating conditions should beavoided by proper initial systemdesign and the careful place-ment of isolation valves. Anydead leg open to steam must beproperly trapped to prevent con-densate build up.

• The use of OD tubing is becom-ing increasingly common forthe distribution of clean steam.Table 15 gives capacities in lb/hfor dry-saturated steam at vari-ous pressures. In order toreduce erosion and noise, it isrecommended that designsshould be based on flow veloc-ities of 100 ft/sec. or less.

SYSTEMDESIGN

Figure 57Steam Trap Discharge Details

Figure 58Steam Trap Discharge—Clean Room

Typical ApplicationSterile barriers, or block and bleedsystems are used extensively inthe biotechnology, pharmaceuti-cal, food, dairy and beverageindustries to prevent contaminat-ing organisms from entering theprocess. A simple example alsoillustrating steam in place, con-densate drainage from a processvessel, is shown in Fig. 59.

In this application, the steamtrap is directly coupled to theprocess pipework, which is nor-mally of sanitary design. It is quitepossible that contamination at thetrap, caused by either biologicalor chemical (corrosion) means,could find its way into the processsystem, thus resulting in failure ofa product batch. Steam traps withcorrosion resistant materials ofconstruction and self drainingfeatures will reduce this risk, tak-ing sanitary standards one stepfurther from the process.

Due to piping arrangements,process fluids will often be flushedthrough the trap. This can oftenresult in plugging if standardindustrial designs of trap are used.

Specialty steam traps arecalled for which have the featuresoutlined above plus the ability forrapid removal from the pipeline andquick disassembly for cleaning.

Clean Area

User Equipment

Vent Filter(alternativelyat kill tank)

Killer Tank/Sewer

CleanSteamTraps

CleanSteamTraps

Condensate

Manifold

To Process Drain

Air Break

Condensate

Air Break

To Process Drain

ManifoldArrangement

Single Trap

CleanSteamTrap

Clean Steam

54

SYSTEMDESIGN

Table 15: Saturated Steam Capacities — OD Tube Capacities in lb/h Tube Size (O.D. x 0.065 inch wall)

Pressure Velocitypsi ft/sec 1/4" 3/8" 1/2" 3/4" 1 11/2" 2" 21/2" 3"

50 — — 5 20 35 90 170 270 3955 80 — 5 10 30 60 145 270 430 635

120 — 5 15 45 85 215 405 650 95050 — 5 10 25 45 110 210 335 490

10 80 — 5 15 35 70 180 330 535 785120 — 10 20 55 110 270 500 800 117550 — 5 10 30 60 155 285 460 675

20 80 — 10 20 50 100 245 460 735 1080120 5 10 25 75 150 370 685 1105 162050 — 5 15 40 80 195 365 585 855

30 80 5 10 30 65 125 310 580 935 1370120 5 15 35 95 190 465 870 1400 205050 — 10 15 50 95 235 440 705 1035

40 80 5 10 25 75 150 375 700 1125 1655120 5 20 40 115 230 556 1050 1690 248050 — 10 20 55 110 275 515 825 1210

50 80 5 15 30 90 180 440 820 1320 1935120 5 20 50 135 265 660 1235 1980 290550 — 10 25 65 125 315 590 945 1385

60 80 5 15 35 105 205 505 940 1510 2215120 5 25 55 155 305 755 1411 2265 332550 5 15 30 80 160 395 735 1180 1730

80 80 5 20 45 130 255 630 1175 1890 2770120 5 30 70 195 380 950 1764 2835 415550 5 15 35 95 190 470 880 1415 2075

100 80 5 25 55 155 305 755 1410 2265 3320120 10 35 85 230 455 1135 2115 3395 497550 5 20 40 115 220 550 1030 1650 2420

120 80 5 30 65 180 355 885 1645 2640 3875120 10 40 95 270 535 1325 2465 3965 5810

A hospital was experiencing continuing problems with anumber of its sterilizers which were having an adverseeffect on both the sterilization process itself and theamount of maintenance required to keep the units in ser-vice. These problems included:• Ineffective sterilization• Prolonged sterilization cycles• Wet and discolored packs• Instrument stains, spotting and rusting• High maintenance of drain traps and controls• Dirty sterilizer chambers requiring frequent cleaning

SolutionIn discussion with the hospital maintenance engineer, theSpirax Sarco Sales Representative offered the opinionthat these problems were a result of a wet and contami-nated steam supply. In a number of cases the steamsupply to the sterilizers was unconditioned, allowing mois-ture and solid particles, such as pipe scale and rust, toenter both the sterilizer jacket and chamber, resulting in theproblems identified by the user.

The solution was to install Spirax Sarco steam filterstations. Each steam filter station is comprised of:• An isolation valve to aid in maintenance.• A separator complete with strainer and drain trap to

remove residual condensate and any entrained moisturebeing carried in suspension within the steam.

• A main line strainer to remove larger solid particles.• A steam filter and drain trap combination.

The steam filter specified was a Spirax Sarco CSF16fitted with a 1 micron absolute filter element. The cleanableCSF16 filter element ensured that 99% of all particles larg-er than 0.1 microns were removed, while the thermostaticsteam trap drained any condensate that formed in the filterbody during operation and periods when the steam supplyto the sterilizer was isolated. These installations resulted insteam supplies free of both moisture and solid particles.

Benefits• Effective sterilization every time• Reduced sterilization cycles and improved productivity• High quality of packs and instruments without spots,

stains or corrosion• Minimal re-work of sterilizer loads• Reduced cleaning and maintenance of sterilizer, drain

traps and controls

Cost SavingsWith the help of the hospital maintenance engineer, asteam filter station payback analysis sheet was completed.The estimated cost of maintenance, the cost associatedwith re-working wet or spotted packs, and the cost due toloss of performance were included in the payback calcula-tion. In total, annual costs were over $25,000 for eachsterilizer. Using this figure a payback period of less thantwo months was established for suitably sized Spirax Sarcosteam filter stations.

Case in Action: Hospital Sterilizer

Figure 59Effective Condensate Drainage

Process/Medium

SteamInlet

ProcessTrap

DripTrap

Testing Steam Traps

55

Increasing attention is being paidin modern plants to means ofassessing steam trap perfor-mance. While it is important toknow if a trap is working normallyor is leaking steam into the con-densate return system, most ofthe available methods of assess-ing trap operation are of muchmore restricted usefulness than isappreciated. To explain this, it isnecessary to consider the modeof operation of each type of trapwhen operating and when failed,and then to see if the proposedtest method can distinguishbetween the two conditions.

Temperature Test MethodsOne well established “method” ofchecking traps is to measure tem-perature, either upstream ordownstream. People use pyrome-ters, remote scanners andtemperature sensitive crayons ortapes, while generations of mainte-nance men have thought theycould assess trap performance byspitting onto the trap and watchinghow the spittle reacted! Certainly, ifa trap has failed closed, the tem-perature at the trap will be lowerthan normal, but equally the equip-ment being drained will also cooldown. The trap is not leakingsteam since it is closed, and thisfailure is only a cause of problemsin applications like steam maindrips where the condensate notdischarged at the faulty trap is car-ried along the steam line. Moreusually, the temperature on theinlet side of the trap will be at orclose to the saturation temperatureof steam at whatever pressure isreaching the trap. Even if the trapwere blowing steam, the tempera-ture remains much the same.

The one exception is in thecase of a temperature sensitivetrap, especially one of the bimetalpattern. If this fails open, then thetemperature at the inlet side willrise from the normal subcooledlevel to saturation values, and thisrise may be detectable if thesteam pressure is a known, con-stant value.

Measuring temperatures onthe downstream side of a trap, bywhatever method, is even lesslikely to be useful. Let’s look firstat a trap discharging through anopen-ended pipe to atmosphere.The pressure at the trap outletmust be only just above atmos-pheric, and the temperature justabove 212°F.

With any condensate presentwith the steam at temperaturesabove 212°F on the inlet side, thecondensate, after passing throughthe trap will flash down to 212°Fand this temperature is the onethat will be found. Any leakingsteam will help evaporate a littlemore of the condensate withoutincreasing the temperature.Again, the only exception whichmay be encountered is the lowpressure steam heating systemwhere thermostatic traps normal-ly discharge at temperaturesbelow 212°F into atmosphericreturn. A temperature of 212°Fhere may indicate a leaking trap.

Discharge of condensate intoa common return line is moreusual than discharge to an openend, of course. The temperaturein the return line should be thesaturation temperature corre-sponding to the return pressure.Any increase in this temperaturewhich may be detected will showthat the return line pressure hasincreased. However, if trap “A”discharging into a line blowssteam and the pressure in theline increases, then the pressureand temperature at traps “B” and“C” and all others on the line willalso increase. Location of thefaulty trap is still not achieved.

Visual DeterminationsThe release of flashing steamfrom condensate nullifies theeffectiveness of test cocks, orthree-way valves diverting a trapdischarge to an open end for testpurposes. It also restricts the infor-mation which can be gained fromsight glasses. Consider a trap dis-charging to an open end some500 lbs. per hour of condensate

from a pressure of 125 psi. Thesteam tables show that eachpound of water carries 324.7 BTUwhich is a144.5 BTU more than itcan carry as liquid at atmosphericpressure. As the latent heat at 0psig is 970.6 BTU/hr., then144.5/970.6 lbs. of flash steam arereleased per pound of conden-sate, or 14.29%, which is some74.45 pounds per hour. The vol-ume of steam at 0 psig is 26.8 cu.ft. per pound, so some 1,995 cu. ft.per hour of flash steam isreleased. The remaining water,500 - 74.45 = 425.55 lbs. has avolume of about 7.11 cu. ft. perhour. Thus, the discharge from thetrap becomes 1995/1995 + 7.11 =99.65% steam and 0.35% water,by volume.

It is sometimes claimed thatan observer can distinguishbetween this “flash” steam andleakage steam by the color of thesteam at the discharge point.While this may be possible when atrap is leaking steam but has nocondensate load at all, so that onlysteam is seen at the discharge, itis obvious that the presence of anycondensate will make such differ-entiation virtually impossible. Itwould be like trying to distinguishbetween 99.65% steam with0.35% water, and perhaps 99.8%steam with 0.20% water!

Trap Discharge SoundsIn a closed piping system, trapdischarge sounds may be a goodindicator of its operation. A simplestethoscope will be of little value,but the sound produced at ultra-high frequencies measured by anultrasonic instrument eliminatesbackground noise interference.Live steam flow produces agreater and steady level of ultra-sound, while flashing condensatetends to have a crackling soundand the level changes with thetrap load. The problem is that theinstrument requires the operatorto make a judgement as to trapcondition which will only be asreliable as his training and experi-ence provide for.

SYSTEMDESIGN

Testing Steam Traps

56

What must be done, using allaudible and visual clues, is todetect normal or abnormalcycling of the discharge. Eventhis method is very fallible, sincethe mode of operation of differenttrap types if not nearly so welldefined as is sometimes thought.Table 16 lists some of the possi-bilities and allows the problem tobe seen more clearly.

It is seen that the “signal” to beobtained from the trap, whethervisual, audio or temperature, isusually going to be so ambiguousas to rely largely on optimism forinterpretation. The one trap whichis fairly positive in its action is thedisc thermodynamic type—if thisis heard or seen to cycle up to tentimes per minute, it is operatingnormally. The cycling rate increas-es when the trap becomes wornand the characteristic “machinegun” sound clearly indicates theneed for remedial action.

Spira-tec Leak Detec-tor SystemLogic says that if it is not possibleto have a universally applicablemethod of checking steam trapsby examining the traps them-selves, then we must see if it canbe done by checking elsewhere.This is what Spirax Sarco hasdone with the Spira-tec system.See Fig. 61 (page 58).

The Spira-tec detector cham-ber is fitted into the condensate

line on the inlet side of the trap. Ifthere is, at this point, a normal flowof condensate towards the trap,together with a small amount of airand the steam needed to make upheat loss from the body of thesteam trap, then all is normal. Onthe other hand, an increased flowof gas along the pipe indicatesthat the trap is leaking.

The chamber contains aninverted weir. Condensate flowsunder this weir and a small holeat the top equalizes the pressureon each side when the steam trapis working normally. An electrodeon the upstream side of the baffledetects the presence of conden-sate by its conductivity which ismuch higher than that of steam.By plugging in the portable indi-cator, it is possible to check if theelectrical circuit is complete whena visual signal indicates that thetrap is working.

If the trap begins to leaksteam, then the pressure on thedownstream side of the weirbegins to fall.The higher pressureon the upstream side drops thecondensate level below the elec-trode and exposes it to steam.The “conductivity” circuit is bro-ken and the indicator light gives a“fail” signal.

The advantage of the systemlies in the very positive signalwhich does not require experi-ence of personal judgementbefore it can be interpreted.

Using suitable wiring, the testpoint can be located remote fromthe sensor chamber or it canhave a multi switch to allow up totwelve (12) chambers to bechecked from a single test loca-tion. When appropriate, anelectronic continuous 16-waychecking instrument can monitorthe chambers and this is readilyconnected into a central EnergyManagement System.

The object of detecting leak-ing steam traps is to correct theproblem. This can mean replace-ment of the whole trap, orperhaps of the faulty part of theinternal mechanism. It is veryuseful indeed to be able to checka repaired trap in the workshopbefore it is installed in the line,and many repair shops now use aSpira-tec chamber as part of abench test rig. The diagramshows a simple hookup whichallows suspect or repaired trapsto be positively checked. (Fig. 60)

Cost Of Steam LeaksThe installation and use of theSpira-tec units does involve somecost, and it is necessary to com-pare this with the cost of steamleakages to see if the expenditureis economically justifiable. Sinceall equipment must wear andeventually fail, we need first anestimate of the average life of asteam trap. Let us assume that ina particular installation, this is,

SYSTEMDESIGN

Table 16: Steam Trap Discharge Modes Mode of Operation

Full or UsualTrap Type No Load Light Load Normal Load Overload Failure Mode

Float & Usually continuous but may Closed,Thermosatic No Action cycle at high pressure Continuous A.V. Open

Inverted Bucket Small Dribble Intermittent Intermittent Continuous Open

Balanced PressureThermostatic No Action May Dribble Intermittent Continuous Variable

Bimetallic Usually Dribble May blast atThermostatic No Action Action high pressures Continuous Open

Usually continuousImpulse Small Dribble with blast at high loads Continuous Open

DiscThermo-Dynamic No Action Intermittent Intermittent Continuous Open

Testing Steam Traps

57

say seven (7) years. This meansthat after the first seven years ofthe life of the plant, in any year anaverage of almost 15% of thetraps will fail. With an annualmaintenance campaign, some ofthe traps will fail just after beingchecked and some just before thenext check. On average, the 15%can be said to have failed for halfthe year, or 7-1/2% of traps failedfor the whole year.

Now, most of the traps in anyinstallation, on the mains drip andtracer installations are probably1/2" or 3/4" size and most of themare oversized, perhaps by a factorof up to 10 or more. Let us assumethat the condenste load is as highas 25% of the capacity of the trap.If the trap were to fail wide open,then some 75% of the valve orificewould be available for steam flow.The steam loss then averages75% of 7-1/2% of the steam flowcapacity of the whole trap popula-tion, or about 5.62%.

The steam flow through awide open seat clearly dependson both pressure differentials andorifice sizes, and orifice sizes in agiven size of trap such as 1/2"usually are reduced as thedesigned working pressureincreases.

Estimating Trap Steam LossSteam loss through a failed opentrap blowing to atmosphere canbe determined from a variant ofthe Napier formula as follows:Steam Flow in lbs/hr =

24.24 X Pa X D2

Where:Pa = Pressure in psi absoluteD = Diameter of trap orifice

in inchesBy multiplying the steam loss

by hours of operation, steam cost(typically $6.00 per 1,000pounds), and by the number offailed traps, total cost of steamsystem loss may be estimated.

The formula above shouldnot be used to directly comparepotential steam loss of one type

of trap against another becauseof differences in failure modes. Inthose that fail open only theinverted bucket trap orifice blowsfull open.Thermostatic types usu-ally fail with their orifice at leastpartially obstructed by the valve,and flow through thermodynamictypes is a function of many pas-sageways and must be related toan equivalent pass area. In everycase, no trap begins losing steamthrough wear or malfunction until

the leakage area exceeds thatneeded by the condensate load.The cost then begins and reach-es the maximum calculated onlywhen the trap fails completely.The object is, of course to preventit from reaching that stage. Thesteam system always functionsbest when traps are selected thatare best for the application andchecked on a regular basis tocontrol losses.

SYSTEMDESIGN

Table 17: Steam Flow through Orifices Discharging to Atmosphere Steam flow, lb/h, when steam gauge pressure is

Diameter 2 5 10 15 25 50 75 100 125 150 200 250 300(inches) psi psi psi psi psi psi psi psi psi psi psi psi psi

1/32 .31 .47 .58 .70 .94 1.53 2.12 2.7 3.3 3.9 5.1 6.3 7.41/16 1.25 1.86 2.3 2.8 3.8 6.1 8.5 10.8 13.2 15.6 20.3 25.1 29.83/32 2.81 4.20 5.3 6.3 8.45 13.8 19.1 24.4 29.7 35.1 45.7 56.4 67.01/8 4.5 7.5 9.4 11.2 15.0 24.5 34.0 43.4 52.9 62.4 81.3 100 1195/32 7.8 11.7 14.6 17.6 23.5 38.3 53.1 67.9 82.7 97.4 127 156 1863/16 11.2 16.7 21.0 25.3 33.8 55.1 76.4 97.7 119 140 183 226 2687/32 15.3 22.9 28.7 34.4 46.0 75.0 104 133 162 191 249 307 3651/4 20.0 29.8 37.4 45.0 60.1 98.0 136 173 212 250 325 401 4779/32 25.2 37.8 47.4 56.9 76.1 124 172 220 268 316 412 507 6035/16 31.2 46.6 58.5 70.3 94.0 153 212 272 331 390 508 627 74511/32 37.7 56.4 70.7 85.1 114 185 257 329 400 472 615 758 9013/8 44.9 67.1 84.2 101 135 221 306 391 476 561 732 902 1073

13/32 52.7 78.8 98.8 119 159 259 359 459 559 659 859 1059 12597/16 61.1 91.4 115 138 184 300 416 532 648 764 996 1228 146015/32 70.2 105 131 158 211 344 478 611 744 877 1144 1410 16761/2 79.8 119 150 180 241 392 544 695 847 998 1301 1604 1907

Figure 60Steam Trap Test Rig

Inexpensive test stand may beused to test steam trap operation.Valves A, B, C, and D are closed andthe trap is attached. Valve C iscracked and valve D is slowly opened.The pressure-reducing valve isadjusted to the rated pressure of thetrap being tested, valve C is closed,and valve A is opened slowly, allowingcondensate flow to the trap until it isdischarged. Valve B is then partiallyopened to allow the condensate todrain out, unloading the trap. Underthis final condition, the trap mustclose with a tight shutoff. With sometrap configurations, a small amount ofcondensate may remain downstreamof the trap orifice. Slow evaporation ofthis condensate will cause smallamounts of flash steam to flow fromthe discharge of the trap even thoughshutoff is absolute.

Strainer

Steam Supply

PressureReducing Valve

PressureGauge

Spira-tecLoss

Detector

TestTrap

ToAtmosphere

DrainDrain

A

C B

D

Spira-tec Trap Leak Detector System for Checking Steam Traps

58

PurposeThe Spira-tec Trap Leak Detector System is designed to indicate if asteam trap is leaking steam. It can be used to check any known type ormake of trap while it is working.

Equipment1. Sensor chamber fitted immediately upstream of the trap (close

coupled), the same size as the trap.

2. Indicator with cable.

3. Where the sensor chamber is not readily accessible, a RemoteTest Point may be fitted at a convenient position, wired backthrough a junction to the sensor chamber. Remote Test Points foreither one chamber or up to 12 chambers, are available.

4. An Automatic Remote Test Point, capable of interfacing with mostBuilding Management Systems, is also available allowing up to 16steam traps to be continuously scanned for steam wastage.

SYSTEMDESIGN

Figure 61

Multiple inaccessible steam trap checking system— Spira-tec sensor chambers, plug tails, wiring (by installer),remote multiple test point, indicator and indicator cable.

Continuous scanning system—Spira-tec AutomaticRemote test point, sensor chambers, plug tails.

Single inaccessible steam trap checking system—Spira-tec sensor chamber, plug tail, wiring (by installer),remote test point, indicator and indicator cable.

Basic steam trap checking system—Spira-tec sensor chamber, indicator and indicator cable.

SensorChamber

Indicator IndicatorCable

IndicatorMultipleRemote

Test Point

Indicator RemoteTest Point

SensorChamber

PlugTail

Wiringby InstallerJunction

AutomaticRemote

Test Point

Steam Meters

59

The steam meter is the basic toolthat provides an operator or man-ager, information vital inmonitoring and maintaining highefficiency levels within a plant orbuilding. This information can besplit into four categories:

Plant Efficiency • Is idle machinery switched off?• Is the plant loaded to capacity?• Is plant efficiency deteriorating

over time indicating the needfor cleaning, maintenance andreplacement of worn parts?

• When do demand levels peakand who are the major users?This information may lead to achange in production methodsto even out steam usage andease the peak load problemson boiler plant.

Energy Efficiency• Is an energy saving scheme

proving effective?• How does the usage and effi-

ciency of one piece of plantcompare with another?

Process Control• Is the optimum amount of

steam being supplied to a cer-tain process?

• Is that steam at the correctpressure and temperature?

Costing and Custody Transfer• How much steam is being sup-

plied to each customer?• How much steam is each

department or building withinan organization using?

Selecting a Steam MeterBefore selecting a steam meter itis important to understand how ameter’s performance is described.The overall performance of ameter is a combination ofAccuracy, Repeatability andTurndown.

AccuracyThis is the measurement(expressed as a percentage) ofhow close the meter’s indicationof flow is to the actual flowthrough the meter. There are twomethods used to express accura-cy (or percentage of uncertainty)and they have very differentmeanings.a.Measured Value or Actual

ReadingExample: Meter is ranged 0-1000 lb/h and has a specifiedaccuracy of ± 3% of ActualReadingAt an indicated flow rate of1,000 lb/h, the true flow rate liesbetween 1,030 and 970 lb/h.At an indicated flow rate of 100lb/h, the true flow rate liesbetween 103 and 97 lb/h.

b.F.S.D. or Full Scale DeflectionExample: Meter is ranged 0-1000 lb/h and has a specifiedaccuracy of ± 3% FSDAt an indicated flow rate of1,000 lb/h, the true flow rate liesbetween 1,030 and 970 lb/h.At an indicated flow rate of 100lb/h, the true flow rate liesbetween 130 and 70 lb/h (i.e. ±30% of Reading !).

RepeatabilityThis describes the ability of ameter to indicate the same valuefor an identical flowrate over andover again. It should not be con-fused with accuracy i.e. the meter’srepeatability may be excellent inthat it shows the same value for anidentical flowrate on several occa-sions, but the reading may beconsistently wrong (or inaccurate).Repeatability is expressed as apercentage of either actual readingor FSD. Good repeatability isimportant for observing trends orfor control e.g. batching.

TurndownSometimes called Turndown

Ratio, Effective Range or evenRangeability. In simple terms, it isthe range of flow rate over whichthe meter will work within theaccuracy and repeatability toler-ances given. If a meter workswithin a certain specified accura-cy at a maximum flow of 1,000lb/h and a minimum flow of 100lb/h, then dividing the maximumby the minimum gives a turndownof 10:1. A wide turndown is partic-ularly important when the flowbeing measured is over a widerange. This could be due to a vari-ation in process e.g. a laundrycould be operating 1 machine or20 machines (20:1 turndown), ordue to seasonal variations inambient temperature if the steamis being used for space heating -the difference in demand betweenmid winter and mid summer canbe considerable. Generally thebigger the turndown the better.The Spirax Sarco family of meterscovers a wide range of sizes, turn-down, accuracy, and repeatabilityas detailed in Table 18.

SYSTEMDESIGN

Table 18: Specification of the Spirax Sarco Meter RangeMeter Type Sizes Accuracy Turndown Repeatability

Orifice Plate 1" -24" ± 3% of Reading 4:1 ± 0.3% of Reading

Gilflo (Made to Order) 2" - 16" ±1% FSD (± 1% of Reading with flow computer) 100:1 ± 0.25% of Reading

Gilflo (S.R.G.) 2" - 8" ± 2% FSD (± 1% of Reading with flow computer) 100:1 ± 0.25% of Reading

Gilflo (I.L.V.A.) 2" - 8" ± 2% FSD (± 1% of Reading with flow computer) 100:1 ± 0.25% of Reading

Spiraflo 1-1/2" - 4" ± 2% of Reading (50% - 100% of meter range) 25-40:1 ± 0.5% of Reading± 1% FSD (1% - 50% of meter range)

Steam Meters

60

Density CompensationFor accurate metering of com-pressible fluids such as gasesand vapors, the actual flowingdensity must be taken intoaccount. This is especially true inthe case of steam. If the actualflowing density of the steam is dif-ferent to the specified density forwhich the meter was originally setup or calibrated, then errors willoccur. These errors can be con-siderable and depend on both themagnitude of difference betweenthe specified density and theactual flowing density, and thetype of meter being used.Example:The steam meter is set up andcalibrated for 100 psig (specificvolume = 3.89 ft3/lb) The steam is actually running at apressure of 85 psig (specific vol-ume = 4.44 ft3/lb).a. Differential Pressure Device

(e.g. Orifice Plate or Gilflo Meter)

Error = s.v. actual -1 x 100√ s.v. specified

Error = 4.44 -1 x 100√ 3.89

Error = 6.8 Therefore the meter will over read by 6.8%

b. Velocity Device(e.g. Vortex Meter)

Error = s.v. actual -1 x 100s.v. specified

Error = 4.44 -1 x 1003.89

Error = 14 Therefore the meter will over read by 14%

In the case of saturated steam,pressure and temperature arerelated and therefore to establishthe flowing density of saturatedsteam, either pressure or temper-ature should be measured. In thecase of superheated steam, pres-sure and temperature can varyindependently from one anotherand therefore to compensate forchanges in density of superheat-ed steam, both pressure andtemperature must be measured.

InstallationNinety percent of all metering fail-ures or problems are installationrelated. Care should be taken toensure that not only is the meterselected suitable for the applica-tion, but that the steam iscorrectly conditioned both toimprove meter performance andprovide a degree of protection,and that the manufacturer’srecommendations regardinginstallation are carefully followed.

Steam ConditioningFor accurate metering of saturatedsteam, irrespective of the metertype or manufacturer, it is impor-tant to condition the steam so thatit is in the form of, or as close aspossible to, a dry gas. This can beachieved by correct steam engi-neering and adequate trapping to

reduce the annular film of waterthat clings to the pipe wall, andeffective separation ahead of themeter to remove much of theentrained droplets of water. It istherefore recommended that asteam conditioning station (asshown in Fig. 62) is positionedupstream of any type of meter onsaturated steam applications. Thiswill enhance accuracy and protectthe meter from the effects of waterdroplets impacting at high velocity.Good steam engineering such asthe use of eccentric reducers,effective insulation and adequatetrapping will also prevent the dan-gerous effects of high velocityslugs of water known as water-hammer which can not onlydestroy meters but will also dam-age any valves or fittings in it’spath.

SYSTEMDESIGN

[ [

[ [

[ [

[ [

Figure 62Steam Conditioning Station

Strainer

Float &ThermostaticSteam Trap

ThermostaticAir Vent

SteamSeparator

CheckValve

IsolatingValve

Steam toMeter

Steam Meters

61

SYSTEMDESIGN

Table 19: Recommended Minimum Straight Lengths (D) for Various Meter Types On Upstream (inlet) side of the primary device Downstream

Meter Type ß Single Two 90° Bends Two or more 90° Bends Reducer Expander Globe Valve Gate Valve All FittingsRatio (3) 90° Bend Same Plane Different Planes 2D to D 0.5D to D Fully Open Fully Open in this table

Orifice Plate 0.30 10 16 34 5 16 18 12 5Orifice Plate 0.35 12 16 36 5 16 18 12 5Orifice Plate 0.40 14 18 36 5 16 20 12 6Orifice Plate 0.45 14 18 38 5 17 20 12 6Orifice Plate 0.50 14 20 40 6 18 22 12 6Orifice Plate 0.55 16 22 44 8 20 24 14 6Orifice Plate 0.60 18 26 48 9 22 26 14 7Orifice Plate 0.65 22 32 54 11 25 28 16 7Orifice Plate 0.70 (4) 28 36 62 14 30 32 20 7Orifice Plate 0.75 36 42 70 22 38 36 24 8Orifice Plate 0.80 46 50 80 30 54 44 30 8Vortex (1) N/A 20 - 40 20 - 40 40 10 - 20 10 - 35 50 20 - 40 5 - 10Spiraflo (2) N/A 6 6 12 6 12 6 6 3 - 6Gilflo (2) N/A 6 6 12 6 12 6 6 3 - 6Gilflo SRG (2) N/A 6 6 12 6 12 6 6 3 - 6Gilflo ILVA (2) N/A 6 6 12 6 12 6 6 3 - 6Notes:1. The table shows the range of straight lengths recommended by various Vortex meter manufacturers.2. Downstream requirements are 3D and 6D when upstream are 6D and 12D respectively.3. ß ratio = Orifice diameter (d) divided by Pipe diameter (D)4. Most Orifice Plates are supplied with a ß ratio of around 0.7 which gives the best pressure recovery without compromising signal strength.

Meter LocationMeters need to be installed indefined lengths of straight pipe toensure accurate and repeatableperformance. These pipe lengthsare usually described in terms ofthe number of pipe diametersupstream and downstream of themeter. For example, an OrificePlate with a Beta ratio of 0.7installed after a 90° bend requiresa minimum of 28 pipe diametersof straight pipe upstream and 7downstream. If the pipe diameteris 6", this is equivalent to 14 feetupstream and 3-1/2 feet down-stream.If the meter is located down-stream of two 90º bends indifferent planes, then the mini-mum straight length requiredupstream of the meter is 62 pipediameters or thirty one feet. Thiscan be difficult to achieve, partic-ularly in fairly complex pipeworksystems, and there may not infact be a location that allowsthese criteria to be met. This is animportant consideration whenselecting a meter.

Table 19 shows the minimum pip-ing requirements for OrificePlates as laid down in the USstandard ASME MFC-3M togeth-er with the manufacturersrecommendations for vortex andspring loaded variable areameters. See Figures II-93, 94, 95,96 (pages 131 and 132).

Figure 63: Moisture Holding Capacity of Air at Varying Temperatures

62

SYSTEMDESIGN

Compressed Air Systems

Air CompressorsHeat is released when air or anygas is compressed.The compres-sor must be cooled to avoidoverheating, usually by circuatingwater through the jackets.Cooling is an important functionwhich must be controlled toensure maximum efficiency.Overcooling wastes water andleads to condensation within thecylinders, with deterioration of thelubricating oils. Undercoolingreduces compressor capacityand can result in serious damageto the compressor. Automatictemperature control of coolingwater flow ensures maximum effi-ciency.

The atmosphere is a mixtureof air and water vapor. Free airhas a greater volume, and mois-ture holding capacity, thancompressed air at the same tem-perature. As the compressed airis cooled after leaving the com-pressor, or between stages,some of the water is precipitated.This water must be drained fromthe system to avoid damage topneumatic valves and tools.

Choice Of Drainer TrapThe quantities of water whichmust be drained from the air arerelatively small, even on quitelarge installations, providing theyare dealt with continuously. It isunusual to need air traps in sizeslarger than 1/2". Except where aworn compressor is allowinglubricating oils to be dischargedwith the compressed air, floatoperated drainers are the bestchoice.

Where the presence in thesystem of water/oil emulsionsinterferes with the operation of floatdrainers, the thermodynamic TDtrap is used. As the TD trap needsan operating pressure of at least50 psi when used as an air drainer,care must be taken when it is usedon small systems. Preferably, theTD’s should be valved off at start-up until the system pressure is upto 50 psi or more.

Sizing Compressed Air TrapsThe amount of water which is to be discharged is determined fromsteam table saturated vapor density or estimated with the help of agraph, Fig. 63 and compression ratio table. An example shows how thisis used.Example:How much water will precipitate from 150 cfm of free air at 70°F and 90%relative humidity when compressed to 100 psig and cooled to 80°F?Air flow = 150 cfm X 60 = 9000 cu. ft/hour.From Fig. 63, at 70°F water in air drawn in will be1.15 X 9000 X 90% = 9.32 lb/h

1000Determine excess moisture due to compression by dividing hourly airflow by factor from Compession Ratio Table 20B (page 64), and convertfor (absolute) temperature.Compression ratio at 100 psig = 7.8Air volume after compression = 9000 X (460 + 80) = 1175 cu. ft./h

7.8 (460 + 70)From Fig. 63, 1000 cu. ft. at 80°F can carry 1.6 lb. of water.1175 cu. ft. will carry 1175 X 1.6 = 1.88 lb/h

1000So, (9.32 lb. – 1.88 lb.) = 7.44 lb/h of water will separate out.

-20 -10 0 10 20 30 40 50

3.0

2.8

2.6

2.4

2.2

2.0

1.8

1.6

1.4

1.2

1.0

.8

.6

.4

.2

0

Air Temp °F

Po

un

ds

Wat

er V

apo

r p

er 1

,000

cu

bic

ft.

at S

atu

rati

on

60 70 80 90 100

63

SYSTEMDESIGN

Distribution LinesThese form the all important linkbetween the compressor and thepoints of usage. If they are under-sized, the desired air flow will beaccompanied by a high pressuredrop. This necessitates extrapower input at the compressor.For example, a pressure at thecompressor of 120 psi where apressure of 100 psi would havesufficed without a high pressuredrop in the lines, needs an addi-tional power input of 10%.

The correct size of com-pressed air lines can be selectedby using Fig. 66 on page 66.Example: 1,000 cu. ft. of free airper minute is to be transmitted at100 PSIG pressure through a 4”line standard weight pipe. Whatwill be the pressure drop due tofriction?

1. Enter the chart at the top atthe point representing 100psig pressure.

2. Proceed vertically downwardto the intersection with hori-zontal line representing 1,000CFM.

3. Next proceed parallel to thediagonal guide lines to theright (or left) to the intersec-tion with the horizontal linerepresenting a 4" line.

4. Proceed vertically downwardto the pressure loss scale atthe bottom of the chart. Youwill note that the pressureloss would be 0.225 psi per100 ft. of pipe.It is usual to size compressed

air lines on velocity, while keepinga watchful eye on pressure drop.

Compressed Air Systems

Drainer InstallationAutomatic drainers are needed atany absorption or refrigerantdryer, and any separator which isinstaled in the air line from theaftercooler, or at the entry to abuilding. They are also needed atthe low points in the distributionlines. (Fig. 64)

Unless fitted close to thepoints being drained, and on lightloads, drainers often need a bal-ance line to allow air to bedisplaced from the piping or thedrainer body as water runs in.Thebalance line is connected abovethe drain point, and should not beupstream of it. See Fig. II-115(page 140).

Figure 64Compressed Air System

LiquidDrainTrap

SafetyValve

Strainer

PressureGauge

Separator

Drain Traps

Drain Trap

Receiver

Water CooledAftercooler

CompressorCoolingWater Control

Instrumentationand Control

System

Line Separator

AirGauging

DrainTrap

SprayGun

BreathingMask

PneumaticTool

Machine ToolAir Bearing

AirOperated

Hoist

DrainTrap

DrainTrap

DrainTrap

64

SYSTEMDESIGN

Compressed Air Systems

Table 20A: Pumped Circulation Water Storage Tanks Compressor Capacity, cfm free air 25 50 100 150 200 300 450 600 800

Tank Capacity, gallons 50 100 180 270 440 550 850 1000 1200

Table 20B: Ratio of Compression Gauge Pressure psi 10 20 30 40 50 60 70 80Ratio of Compression 1•68 2•36 3•04 3•72 4•40 5•08 5•76 6•44

Gauge Pressure psi 90 100 110 120 130 140 150 200Ratio of Compression 7•12 7•8 8•48 9•16 9•84 10•52 11•2 14•6

Table 21: Cooling Water Flow Rates Water Flow per

Compressor operating at 100 psi 100 cfm free air

Single Stage 1.2 gpmSingle Stage with Aftercooler 4.8 gpmTwo Stage 2.4 gpmTwo Stage with Aftercooler 6 gpm

An air velocity of 20 to 30 ft/sec-ond or 1200 to 1800 ft/minute, issufficiently low to avoid excessivepressure loss and to prevent re-entrainment of precipitatedmoisture. In short branches to theair-using equipment, volocities upto 60-80 ft/second or 3600-4800ft/minute are often acceptable.

Checking Leakage LossesAir line leaks both waste valuableair and also contribute to pressureloss in mains by adding uselessload to compressors and mains.Hand operated drain valves are acommon source of leakage thatcan be stopped by using reliableautomatic drain traps. Here is asimple way of making a roughcheck of leakage loss. First, esti-mate the total volume of systemfrom the receiver stop valve to thetools, including all branches, sep-arators, etc. Then with noequipment in use, close the stopvalve and with a stop watch notethe time taken for the pressure inthe system to drop by 15 psi. Theleakage loss per minute is:

Cu. ft. of Free AirLoss per Minute

=Volume of System Cu. Ft.Time in Minutes to Drop

Pressure 15 psi

Compressor CoolingAir cooled compressors, formerlyavailable only in the smaller sizes,are now found with capacities upto 750 cfm, and rated for pres-sures up to 200 psi. The cylindersare finned and extra cooling is pro-vided by arranging the flywheel ora fan to direct a stream of air on tothe cylinder. Such compressorsshould not be located in a con-fined space where ambient airtemperatures may rise and pre-vent adequate cooling.

Water cooled compressorshave water jackets around thecylinders, and cooling water is cir-culated through the jackets.Overcooling is wasteful and cost-ly, and can lead to corrosion andwear within the compressor.Temperature control of the cool-ing water is important.

Pumped CirculationLarger single-staged compres-sors may require a pump toincrease the water velocity whenthermo-siphon circulation is tooslow. The size of the water tankshould be discussed with thecompressor manufacturer, but inthe absence of information, Table20A can be used as a guide forcompressors operating at up to100 psi.

Single Pass CoolingThe hook-up shown in Fig. II-103(page 135) is used where waterfrom the local supply is passeddirectly through the compressorto be cooled. With increasingdemands on limited waterresources, many water supplyauthorities do not permit use ofwater in this way, especiallywhere the warmed water is dis-charged to waste, and require theuse of recirculation systems.

When single pass cooling isused, temperature controls willhelp ensure consumption is mini-mized.To avoid the sensor controlbeing in a dead pocket if the con-trol valve ever closes, a smallbleed valve is arranged to bypassthe control valve. This ensures asmall flow past the sensor at alltimes.

Many compressor manufactur-ers suggest that the temperature ofthe water leaving the cylinder jack-ets should be in the range of95-120°F. Typical water flow ratesneeded for compressors are shownin Table 21, but again, these shouldbe checked with the manufacturerwhere possible.The supply of cooling water cansometimes be taken from the soft-ened boiler feed water storagetank.The warmed outlet water thenbecomes a source of pre-heatedmakeup water for the boiler.

65

SYSTEMDESIGN

Compressed Air Systems

Closed Circuit CoolingEspecially with large compres-sors, economies are obtainedwhen the cooling water is recy-cled in a closed circuit. This alsominimizes any scaling in the jack-ets and coolers. The heat may bedissipated at a cooling tower or amechanical cooler, or sometimesused for space heating in adja-cent areas.Usually with closed circuit cool-ing, it is preferable to usethree-way temperature controls.Where cooling towers are used,freeze protection of the towersump may be needed in winterconditions. Often a steam heatingcoil is installed in the sump with atemperature control set to openwhen the water temperature fallsto say 35°F. A three-way temper-ature control diverts water directto the sump instead of to the topof the tower in low temperatureconditions. Heat loss from thesump itself then provides suffi-cient cooling.

Lubricant CoolersOn large reciprocating compres-sors, and especially on rotaryvane compressors, the lubricatingoil is usually cooled by passing itthrough a heat exchanger. Here itgives up heat to cooling waterand again the coolant flow shouldbe temperature controlled. SeeFig. 65.

Figure 65Temperature Control of Water to Oil Cooler

Compressor Equipment GuideApprox. CFM Air =

Compressor HP X 5GPM Cooling Water =

42.5 X HP/Cylinder8.33 X Temp. Rise

of Cooling Water

Air is a vital utility for all process plants, primarily to powercontrol valves, measurement devices and to drive tools,pumps, machinery, etc. Outdoor facilities (i.e. refineriesand chemical plants) are faced with continual problemsrelated to water accumulation in the air system.

Free and compressed air carries varying volumes ofwater at different pressures and temperatures. This affectsthe amount of entrained water that must be drained in dif-ferent parts of the system for effective operation.

Desiccant dryers critical for removing water from com-pressed air distributed to instruments and controlsbecome water-logged due to excess moisture entrained inthe free-air supplied. When this occurs, the dryers shutdown, curtailing air for distribution.

The heat transfer across the wall of distribution pipingcreates additional condensing. Moisture, entrained in the airflow, exceeds the capacity of the coalescent filters installedat the point of use. The air-using equipment is then floodedwith water, affecting proper operation. This can ruin gaugesand instruments and affect control accuracy.

SolutionOver 30 separators with drain traps were installed in prob-lem areas providing proper drainage of equipment.

Benefits• Continuous operation of desiccant dryers, assuring

uninterrupted air supply.• Working with dry air, instrument accuracy is more con-

sistent.• Damage to gauges and other instruments, caused by

entrained water, is prevented, reducing maintenancecost.

• Air hose stations deliver dry air immediately eliminatingdelay/inconvenience of having to manually drain waterfrom the hoses before use.

Case in Action: Air System Moisture Separation/Drainage

Bypass ifnecessary

Reverse ActingTemperature

Control

SensorStrainer

66

SYSTEMDESIGN

Compressed Air Line Pressure Drop

Figure 66: Compressed Air Line Pressure Drop

Table 22: Calculation of Pipe Expansion Expansion (∆) = L0 x ∆t x aa (inches)

L0 = Length of pipe between anchors (ft)

∆t = Temperature difference (°F)

a = Expansion coefficient

For Temp. Range 30 32 32 32 32 32 32 32(°F) to to to to to to to to

32 212 400 600 750 900 1100 1300

Mild Steel0.1-0.2% C 7•1 7•8 8•3 8•7 9•0 9•5 9•7 —

Alloy Steel1% Cr. 1/2% Mo 7•7 8•0 8•4 8•8 9•2 9•6 9•8 —

Stainless Steel18% Cr. 8% Ni 10•8 11•1 11•5 11•8 12•1 12•4 12•6 12•8

Expansion Coefficient aa x 10-5 (inches)

Example 7•1 x 10-5 = 0.000071

Figure 67: Expansion Chart for Mild Steam PipePipe Expansion

1/2 3/4 1 11/2 2 3 4 6

700600500400

300

200

150125

100

75

50

25

16

Expansion of pipe (inches)8

12 16 20 26 32 40

Temperature difference (°F)100 200 300 400500600

700

800

900

Temperature ofSaturated Steam

psi gauge Temp (°F)5 228

10 24025 26750 29875 320

100 338125 353150 366200 388250 406300 421400 448500 470

.03 .04 .06 .08 .1 .2

12

10

8

6

5

431/2

3

21/2

2

11/2

11/4

1

3/4

1/2

Pressure Drop lbs per sq. inch per 100 feet.3 .4 .5 .6 .8 1.0 1.5 2

10000

600040003000

2000

1000

600

400300

200

100

60

4030

20

10

400 300 200 100 20 10 5 01412 10 8 7Gauge Pressure – lb. per sq. inch Abs. Pres. – P.S.I.A.

Len

gth

of

pip

e (f

eet)

No

min

al P

ipe

Siz

es –

Std

.wei

gh

t p

ipe

Cu

bic F

eet – Free A

ir per M

inu

te

6 5

67

SYSTEMDESIGN

Heat Transfer

Table 23: Heat Transfer Average Heat Loss from Oil in Storage Tanks and Pipe Lines

Position Oil Temperature Unlagged* Lagged*

Tank Sheltered Up to 50°F 1.2 .3Up to 80°F 1.3 .325Up to 100°F 1.4 .35

Tank Exposed Up to 50°F 1.4 .35Up to 80°F 1.5 .375Up to 100°F 1.6 .4

Tank In Pit All Temperatures 1.2 —

Pipe Sheltered Up to 80°F 1.5 .375Line 80 to 260°F 2.3 .575

Pipe Exposed Up to 80°F 1.8 .45Line 80 to 260°F 2.75 .7

*Heat Transfer Rate in BTU/h ft2 °F temperature differencebetween oil and surrounding air

For rough calculations, it may be taken that 1 ton of fuel oiloccupies 36.4 ft3. The specific heat capacity of heavy fuel is0.45 to 0.48 Btu/lb °F.

Heat Transfer from Steam CoilsApproximately 20 Btu/h ft2 of heating surface per °F differencebetween oil and steam temperature.

Heat Transfer from Hot Water CoilsApproximately 10 Btu/h ft2 of heating surface per °F differencebetween oil and water temperature.

Table 24: Heat Transmission Coefficients In Btu per sq. ft. per hr. per °F.

Water Cast Iron Air or Gas 1.4

Water Mild Steel Air or Gas 2.0

Water Copper Air or Gas 2.25

Water Cast Iron Water 40 to 50

Water Mild Steel Water 60 to 70

Water Copper Water 62 to 80

Air Cast Iron Air 1.0

Air Mild Steel Air 1.4

Steam Cast Iron Air 2.0

Steam Mild Steel Air 2.5

Steam Copper Air 3.0

Steam Cast Iron Water 160

Steam Mild Steel Water 185

Steam Copper Water 205

Steam Stainless Steel Water 120

The above values are average coefficients for practically still fluids.

The coefficients are dependent on velocities of heating andheated media on type of heating surface, temperature differenceand other circumstances. For special cases, see literature,and manufacturer’s data.

Table 25: Heat Loss from Open Tanks Liquid Heat Loss From Liquid Suface Heat Loss Through Tank WallsTemp. BTU/ft2 h BTU/ft2 h

°F Evap. Rad. Total Bare InsulationLoss Loss Steel 1" 2" 3"

90 80 50 130 50 12 6 4100 160 70 230 70 15 8 6110 240 90 330 90 19 10 7120 360 110 470 110 23 12 9130 480 135 615 135 27 14 10140 660 160 820 160 31 16 12150 860 180 1040 180 34 18 13160 1100 210 1310 210 38 21 15170 1380 235 1615 235 42 23 16180 1740 260 2000 260 46 25 17190 2160 290 2450 290 50 27 19200 2680 320 3000 320 53 29 20210 3240 360 3590 360 57 31 22

Table 26: Heat Emission Rates from PipesSubmerged in Water

Published Overall Heat Transfer Rates Btu/ft2 h °F

Tank Coils, Steam/Water(Temperature difference 50°F) 100 to 225

Tank Coils, Steam/Water(Temperature difference 100°F) 175 to 300

Tank Coils, Steam/Water(Temperature difference 200°F) 225 to 475

Reasonable Practical Heat Transfer Rates

Tank Coils, low pressure with natural circulation 100

Tank Coils, high pressure with natural circulation 200

Tank Coils, low pressure with assisted circulation 200

Tank Coils, high pressure with assisted circulation 300

Table 27: Heat Emission Coefficients fromPipes Submerged in Miscellaneous Fluids

The viscosity of fluids has a considerable bearing on heat trans-fer characteristics and this varies in any case with temperature.The following figures will therefore serve only as a rough guide.

Immersed steam coil, medium pressure, natural convection.

Btu/ft2 h °F difference

Light Oils 30Heavy Oils 15 to 20Fats* 5 to 10

Immersed steam coil, medium pressure, forced convection.

Btu/ft2 h °F difference

Light Oils (220 SSU at 100°F) 100Medium Oils (1100 SSU at 100°F) 60Heavy Oils (3833 SSU at 100°F) 30

* Certain materials such as tallow and margarine are solid at normal temperatures but have quite low viscosities in the molten state.

Typical Steam Consumption Rates

68

SYSTEMDESIGN

Table 28: Typical Steam Consumption RatesOperating Lbs per hrpressure

PSIG In use Maximum

BAKERIESDough room trough, 8 ft long 10 4Proof boxes, 500 cu ft capacity 7

Ovens: Peel Or Dutch Type 10White bread, 120 sq ft surface 29Rye bread, 10 sq ft surface 58Master Baker Ovens 29Century Reel, w/pb per 100 lb bread 29Rotary ovens, per deck 29Bennett 400, single deck 44Hubbard (any size) 58Middleby-Marshall, w/pb 58Baker-Perkins travel ovens, long tray (per 100 lbs) 13Baker-Perkins travel ovens, short tray (per 100 lbs) 29General Electric 20Fish Duothermic Rotary, per deck 58Revolving ovens: 8-10 bun pan 29

12-18 bun pan 5818-28 bun pan 87

BOTTLE WASHING 5Soft drinks, beer, etc: per 100 bottles/min 310Mill quarts, per 100 cases per hr 58

CANDY and CHOCOLATE 70Candy cooking, 30-gal cooker, 1 hour 46Chocolate melting, jacketed, 24” dia 29Chocolate dip kettles, per 10 sq ft tank surface 29Chocolate tempering, top mixing each 20 sq ft active surface 29Candy kettle per sq ft of jacket 30 60Candy kettle per sq ft of jacket 75 100

CREAMERIES and DAIRIES 15-75Creamery cans 3 per min 310Pasteurizer, per 100 gal heated 20 min 232

DISHWASHERS 10-302-Compartment tub type 58Large conveyor or roller type 58Autosan, colt, depending on size 29 117Champion, depending on size 58 310Hobart Crescent, depending on size 29 186Fan Spray, depending on size 58 248Crescent manual steam control 30Hobart Model AM-5 10Dishwashing machine 15-20 60-70

HOSPITAL EQUIPMENT 40-50Stills, per 100 gal distilled water 102Sterilizers, bed pan 3Sterilizers, dressing, per 10” length, approx. 7Sterilizers, instrument, per 100 cu in approx. 3Sterilizers, water, per 10 gal, approx. 6

Disinfecting Ovens, Double Door: 40-50Up to 50 cu ft, per 10 cu ft approx. 2950 to 100 cu ft, per 10 cu ft approx. 21100 and up, per 10 cu ft, approx. 16

Sterilizers, Non-Pressure TypeFor bottles or pasteurization 40Start with water at 70°F, maintained for 20 minutes at boiling at a depth of 3” 51 69

Instruments and Utensils:Start with water at 70°F, boil vigorously for 20 min: 40

Depth 3-1/2”: Size 8 X 9 X 18” 27 27Depth 3-1/2”: Size 9 X 20 X 10” 30 30Depth 4”: Size 10 X 12 X 22” 39 39Depth 4”: Size 12 X 16 X 24” 60 60Depth 4”: Size 10 X 12 X 36” 66 66Depth 10”: Size 16 X 15 X 20” 92 92Depth 10”: Size 20 X 20 X 24” 144 144

LAUNDRY EQUIPMENT 100Vacuum stills, per 10 gal 16Spotting board, trouser stretcher 29Dress finisher, overcoat shaper, each 58Jacket finisher, Susie Q, each 44

Typical Steam Consumption Rates

69

SYSTEMDESIGN

Table 28: Typical Steam Consumption RatesOperating Lbs per hrpressure

PSIG In use MaximumAir vacuum finishing board, 18” Mushroom Topper, ea. 20Steam irons, each 4

Flat Iron Workers: 10048” X 120”, 1 cylinder 24848” X 120”, 2 cylinder 3104-Roll, 100 to 120” 2176-Roll, 100 to 120” 3418-Roll, 100 to 120” 465

Shirt Equipment 100Single cuff, neckband, yoke No. 3, each 7Double sleeve 13Body 29Bosom 44

Dry Rooms 100Blanket 20Conveyor, per loop, approx. 7Truck, per door, approx. 58Curtain, 50 X 114 29Curtain, 64 X 130 58Starch cooker, per 10 gal cap 7Starcher, per 10-in. length approx. 5Laundry presses per 10-in. length approx. 7Handy irons, per 10-in. length, approx. 5Collar equipment: Collar and Cuff Ironer 21Deodorizer 87Wind Whip, single 58Wind Whip, double 87

Tumblers, General Usage Other Source 10036”, per 10” length, approx. 2940”, per 10” length, approx. 3842”, per 10” length, approx. 52Vorcone, 46” X 120” 310Presses, central vacuum, 42” 20Presses, steam, 42” 29

PLASTIC MOLDINGEach 12 to 15 sq ft platen surface 125 29

PAPER MANUFACTURECorrugators per 1,000 sq ft 175 29Wood pulp paper, per 100 lb paper 50 372

RESTAURANT EQUIPMENT 5-20Standard steam tables, per ft length 36Standard steam tables, per 20 sq ft tank 29Bain Marie, per ft length, 30” wide 13Bain Marie, per 10 sq ft tank 29Coffee urns, per 10 gal, cold make-up 133-compartment egg boiler 13Oyster steamers 13Clam or lobster steamer 29

Steam Jacketed Kettles 5-2010 gal capacity 13 10625 gal stock kettle 29 12440 gal stock kettle 44 14060 gal stock kettle 58 152

Plate And Dish Warmers 5-20Per 100 sq ft shelf 58Per 20 cu ft shelf 29Warming ovens, per 20 cu ft 29Direct vegetable steamer, per compartment 29 80Potato steamer 29 80Morandi Proctor, 30 comp., no return 87Pot sink, steam jets, average use 29Silver burnishers, Tahara 58

SILVER MIRRORINGAverage steam tables 5 102

TIRE SHOPS 100Truck molds, large 87Truck molds, medium 58Passenger molds 29Section, per section 7Puff Irons, each 7

70

SYSTEMDESIGN

Specific Heats and Weights

Table 29: Specific Heats and Weights: Various SolidsSpecific Heat,

Specific B.t.u. per Lb.Material Gravity per °F

Aluminum .................................... 2.55-2.8 .22Andalusite ................................... .17Antimony ..................................... .05Aatite ........................................... .20Asbestos ..................................... 2.1-2.8 .20Augite .......................................... .19Bakelite, wood filler ..................... .33Bakelite, asbestos filler ............... .38Barite........................................... 4.5 .11Barium......................................... 3.5 .07Basalt rock .................................. 2.7-3.2 .20Beryl............................................ .20Bismuth ....................................... 9.8 .03Borax........................................... 1.7-1.8 .24Boron........................................... 2.32 .31Cadmium..................................... 8.65 .06Calcite, 32-100F.......................... .19Calcite, 32-212F.......................... .20Calcium ....................................... 4.58 .15Carbon ........................................ 1.8-2.1 .17Carborundum .............................. .16Cassiterite ................................... .09Cement, dry ................................ .37Cement, powder.......................... .2Charcoal...................................... .24Chalcopyrite ................................ .13Chromium.................................... 7.1 .12Clay ............................................. 1.8-2.6 .22Coal............................................. 64-.93 .26-.37Cobalt.......................................... 8.9 .11Concrete, stone........................... .19Concrete, cinder.......................... .18Copper ........................................ 8.8-8.95 .09Corundum ................................... .10Diamond...................................... 3.51 .15Dolomite rock .............................. 2.9 .22Fluorite ........................................ .22Fluorspar ..................................... .21Galena......................................... .05Garnet ......................................... .18Glass, common ........................... 2.4-2.8 .20Glass, crystal .............................. 2.9-3.0 .12Glass, plate ................................. 2.45-2.72 .12Glass, wool.................................. .16Gold............................................. 19.25-19.35 .03Granite ........................................ 2.4-2.7 .19Hematite...................................... 5.2 .16Hornblende.................................. 3.0 .20Hypersthene................................ .19Ice, -112F.................................... .35Ice, -40F...................................... .43Ice, -4F........................................ .47

Specific Heat,Specific B.t.u. per Lb.

Material Gravity per °F

Ice, 32F ....................................... .49Iridium ......................................... 21.78-22.42 .03Iron, cast ..................................... 7.03-7.13 .12Iron, wrought ............................... 7.6-7.9 .12Labradorite .................................. .19Lava ............................................ .20Lead ............................................ 11.34 .03Limestone.................................... 2.1-2.86 .22Magnetite .................................... 3.2 .16Magnesium.................................. 1.74 .25Malachite..................................... .18Manganese ................................. 7.42 .11Marble ......................................... 2.6-2.86 .21Mercury ....................................... 13.6 .03Mica............................................. .21Molybdenum................................ 10.2 .06Nickel .......................................... 8.9 .11Oligloclose................................... .21Orthoclose................................... .19Plaster of Paris............................ 1.14Platinum ...................................... 21.45 .03Porcelain ..................................... .26Potassium.................................... 0.86 .13Pyrexglass................................... .20Pyrolusite .................................... .16Pyroxylin plastics......................... .34-.38Quartz, 55-212F.......................... 2.5-2.8 .19Quartz, 32F................................. .17Rock salt ..................................... .22Rubber ........................................ .48Sandstone................................... 2.0-2.6 .22Serpentine................................... 2.7-2.8 .26Silk .............................................. .33Silver ........................................... 10.4-10.6 .06Sodium........................................ 0.97 .30Steel ............................................ 7.8 .12Stone........................................... .20Stoneware ................................... .19Talc.............................................. 2.6-2.8 .21Tar ............................................... 1.2 .35Tallurium...................................... 6.0-6.24 .05Tin ............................................... 7.2-7.5 .05Tile, hollow .................................. .15Titanium ...................................... 4.5 .14Topaz........................................... .21Tungsten...................................... 19.22 .04Vanadium .................................... 5.96 .12Vulcanite...................................... .33Wood........................................... .35-.99 .32-.48Wool ............................................ 1.32 .33Zinc blend.................................... 3.9-4.2 .11Zinc ............................................. 6.9-7.2 .09

71

SYSTEMDESIGN

Specific Heats and Weights

Table 30: Specific Heats and Weights: Various LiquidsSpecific Heat,

Specific B.t.u. per Lb.Liquid Gravity per °FAcetone....................................... 0.790 .51Alcohol, ethyl 32°F ...................... 0.789 .55Alcohol, ethyl, 105°F ................... 0.789 .65Alcohol, methyl, 40-50°F............. 0.796 .59Alcohol, methyl, 60-70°F............. 0.796 .60Ammonia, 32°F ........................... 0.62 1.10Ammonia, 104°F ......................... 1.16Ammonia, 176°F ......................... 1.29Ammonia, 212°F ......................... 1.48Ammonia, 238°F ......................... 1.61Anilin ........................................... 1.02 .52Benzol ......................................... .42Calcium Chloride......................... 1.20 .73Castor Oil .................................... .43Citron Oil ..................................... .44Diphenylamine ............................ 1.16 .46Ethyl Ether................................... .53Ethylene Glycol ........................... .53Fuel Oil........................................ .96 .40Fuel Oil........................................ .91 .44

Specific Heat,Specific B.t.u. per Lb.

Liquid Gravity per °FFuel Oil........................................ .86 .45Fuel Oil........................................ .81 .50Gasoline ...................................... .53Glycerine..................................... 1.26 .58Kerosene..................................... .48Mercury ....................................... 13.6 .033Naphthalene................................ 1.14 .41Nitrobenzole ................................ .36Olive Oil....................................... .91-.94 .47Petroleum.................................... .51Potassium Hydrate..................... 1.24 .88Sea Water ................................... 1.0235 .94Sesame Oil ................................. .39Sodium Chloride ......................... 1.19 .79Sodium Hydrate .......................... 1.27 .94Soybean Oil................................. .47Toluol........................................... .866 .36Turpentine ................................... .87 .41Water........................................... 1 1.00Xylene ......................................... .861-.881 .41

Table 31: Specific Heats and Weights: Gas and VaporsSpecific Heat, Specific Heat,B.t.u. per Lb. B.t.u. per Lb.

Gas or Vapor per °F per °Fat Constant at Constant

Pressure VolumeAcetone....................................... .35 .315Air, dry, 50°F ............................... .24 .172Air, dry, 32-392°F ........................ .24 .173Air, dry, 68-824°F ........................ .25 .178Air, dry 68-1166°F....................... .25 .184Air, dry, 68-1472°F ...................... .26 .188Alcohol, C2H5OH......................... .45 .398Alcohol, CH3OH .......................... .46 .366Ammonia ..................................... .54 .422Argon........................................... .12 .072Benzene, C6H6............................ .26 .236Bromine....................................... .06 .047Carbon dioxide ............................ .20 .150Carbon monoxide........................ .24 .172Carbon disulphide ....................... .16 .132Chlorine....................................... .11 .082Chloroform .................................. .15 .131

Specific Heat, Specific Heat,B.t.u. per Lb. B.t.u. per Lb.

Gas or Vapor per °F per °Fat Constant at Constant

Pressure VolumeEther............................................ .48 .466Hydrochloric acid ........................ .19 .136Hydrogen..................................... 3.41 2.410Hydrogen sulphide ...................... .25 .189Methane ...................................... .59 .446Nitrogen....................................... .24 .170Nitric oxide .................................. .23 .166Nitrogen tetroxide........................ 1.12 1.098Nitrous oxide ............................... .21 .166Oxygen........................................ .22 .157Steam, 1 psia

120-600 °F ................................ .46 .349Steam, 14.7 psia

220-600 °F ................................ .47 .359Steam, 150 psia

360-600 °F ................................ .54 .421Sulphur dioxide ........................... .15 .119

72

SYSTEMDESIGN

Specific Heats and Weights

Table 32: Specific Heats and Weights: FoodstuffsSpecific Heat, Specific Heat,B.t.u. per Lb. B.t.u. per Lb.

Food per °F per °Fabove freezing below freezing

Apples ......................................... .87 .42Apricots, fresh ............................. .88 .43Artichokes ................................... .87 .42Asparagus ................................... .94 .45Asparagus beans ........................ .88 .43Avocados..................................... .72 .37Bananas...................................... .80 .40Barracuda.................................... .80 .40Bass ............................................ .82 .41Beef, carcass .............................. .68 .48Beef, flank ................................... .56 .32Beef, Loin .................................... .66 .35Beef, rib....................................... .67 .36Beef, round.................................. .74 .38Beef, rump .................................. .62 .34Beef, shanks ............................... .76 .39Beef, corned................................ .63 .34Beets ........................................... .90 .43Blackberries ................................ .87 .42Blueberries.................................. .87 .42Brains .......................................... .84 .41Broccoli ....................................... .92 .44Brussels sprouts ......................... .88 .43Butter........................................... .30 .24Butterfish ..................................... .77 .39Cabbage...................................... .94 .45Carp ............................................ .82 .41Carrots ........................................ .91 .44Cauliflower .................................. .93 .44Celery.......................................... .94 .45Chard .......................................... .93 .44Cherries, sour ............................. .88 .43Cherries, sweet ........................... .84 .41Chicken, squab ........................... .80 .40Chicken, broilers ......................... .77 .39Chicken, fryers ............................ .74 .38Chicken, hens ............................. .65 .35Chicken, capons.......................... .88 .44Clams, meat only ........................ .84 .41Coconut, meat and milk .............. .68 .36Coconut, milk only....................... .95 .45Codfish ........................................ .86 .42Cod Roe...................................... .76 .39Corn ............................................ .84 .423Cowpeas, fresh ........................... .73 .39Cowpeas, dry .............................. .28 .22Crabs........................................... .84 .41Crab apples................................. .85 .41Cranberries ................................. .90 .43Cream ......................................... .90 .38Cucumber.................................... .98 .45Currants ...................................... .97 .45Dandelion greens........................ .88 .43Dates........................................... .20 .007Eels ............................................. .77 .39

Specific Heat, Specific Heat,B.t.u. per Lb. B.t.u. per Lb.

Food per °F per °Fabove freezing below freezing

Eggs............................................ .76 .40Eggplant ...................................... .94 .45Endive ......................................... .95 .45Figs, fresh ................................... .82 .41Figs, dried ................................... .39 .26Figs, candied............................... .37 .26Flounders .................................... .86 .42Flour ............................................ .38 .28Frogs legs ................................... .88 .44Garlic........................................... .79 .40Gizzards ...................................... .78 .39Goose.......................................... .61 .34Gooseberry ................................. .86 .42Granadilla.................................... .84 .41Grapefruit .................................... .91 .44Grapes ........................................ .86 .42Grape juice.................................. .82 .41Guavas........................................ .86 .42Guinea hen ................................. .75 .38Haddoock .................................... .85 .42Halibut ......................................... .80 .40Herring, smokes.......................... .71 .37Horseradish, fresh....................... .79 .40Horseradish, prepared ................ .88 .43Ice Cream ................................... .74 .40Kale ............................................. .89 .43Kidneys ....................................... .81 .40Kidney beans, dried .................... .28 .23Kohlrabi ....................................... .92 .44Kumquats .................................... .85 .41Lamb, carcass............................. .73 .38Lamb, leg .................................... .71 .37Lamb, rib cut ............................... .61 .34Lamb, shoulder ........................... .67 .35Lard ............................................. .54 .31Leeks........................................... .91 .44Lemons ....................................... .91 .44Lemon joice................................. .92 .44Lettuce ........................................ .96 .45Lima beans ................................. .73 .38Limes........................................... .89 .43Lime juice.................................... .93 .44Litchi fruits, dried......................... .39 .26Lobsters ...................................... .82 .41Loganberries ............................... .86 .42Loganberry joice ......................... .91 .44Milk, cow ..................................... .90 .47Mushrooms, fresh ....................... .93 .44Mushrooms, dried ....................... .30 .23Muskmelons ................................ .94 .45Nectarines................................... .86 .42Nuts............................................. .28 .24Olives, green ............................... .80 .40Onions......................................... .90 .43Onions, Welsh ............................. .91 .44

73

SYSTEMDESIGN

Specific Heat and Weights

Table 32: Specific Heats and Weights: FoodstuffsSpecific Heat, Specific Heat,B.t.u. per Lb. B.t.u. per Lb.

Food per °F per °Fabove freezing below freezing

Oranges, fresh ............................ .90 .43Orange juice................................ .89 .43Oysters........................................ .84 .41Peaches, Georgia ....................... .87 .42Peaches, N. Carolina .................. .89 .43Peaches, Maryland ..................... .90 .43Peaches, New Jersey.................. .91 .44Peach juice, fresh........................ .89 .43Pears, Bartlett ............................. .89 .43Pears, Beurre Bosc ..................... .85 .41Pears, dried................................. .39 .26Peas, young ................................ .85 .41Peas, medium ............................. .81 .41Peas, old ..................................... .88 .43Peas, split.................................... .28 .23Peppers, ripe............................... .91 .44Perch........................................... .82 .41Persimmins.................................. .72 .37Pheasant ..................................... .75 .36Pickerel ....................................... .84 .41Pickels, sweet.............................. .82 .41Pickels, sour and dill ................... .96 .45Pickels, sweet mixed ................... .78 .29Pickels, sour mixed ..................... .95 .45Pig’s feet, pickled ........................ .50 .31Pike ............................................. .84 .41Pineapple, fresh .......................... .88 .43Pineapple, sliced or crushed....... .82 .41Pineapple joice............................ .90 .43Plums .......................................... .89 .43Pomegranate............................... .85 .41Pompano..................................... .77 .39Porgy........................................... .81 .40Pork, bacon ................................. .36 .25Pork, ham.................................... .62 .34Pork, loin ..................................... .66 .35Pork, shoulder ............................. .59 .33Pork, spareribs ............................ .62 .34Pork, smoked ham ...................... .65 .35Pork, salted ................................. .31 .24Potatoes ...................................... .82 .41Prickly pears ............................... .91 .43Prunes......................................... .81 .40Pumpkin ...................................... .92 .44Quinces ....................................... .88 .43Rabbit.......................................... .76 .39Radishes ..................................... .95 .45Raisins ........................................ .39 .26Raspberries, black ...................... .85 .41Raspberries, red ......................... .89 .43Raspberry juice, black................. .91 .44Raspberry juice, red.................... .93 .44Reindeer...................................... .73 .37Rhubarb ...................................... .96 .45

Specific Heat, Specific Heat,B.t.u. per Lb. B.t.u. per Lb.

Food per °F per °Fabove freezing below freezing

Rose Apple ................................. .89 .43Rutabagas................................... .91 .44Salmon........................................ .71 .37Sand dab, California ................... .86 .42Sapodilla ..................................... .91 .44Sapote......................................... .73 .37Sauerkraut................................... .93 .44Sausage, beef and pork.............. .56 .32Sausage, bockwurst.................... .71 .37Sausage, bologna ....................... .71 .37Sausage, frankfurt....................... .69 .36Sausage, salami ......................... .45 .28Sardines ...................................... .77 .39Shad............................................ .76 .39Shrimp......................................... .83 .41Spanish mackerel........................ .73 .39Shad............................................ .76 .39Shrimp......................................... .83 .41Spanish mackerel........................ .73 .39Strawberries ................................ .95 .45Strawberry juice .......................... .79 .39String beans................................ .91 .44Sturgeon, raw.............................. .83 .41Sturgeon, smoked....................... .71 .37Sugar apple, fresh....................... .79 .39Sweet potatoes ........................... .75 .38Swordfish .................................... .80 .40Terrapin ....................................... .80 .40Tomatoes, red ............................. .95 .45Tomatoes, green ......................... .96 .45Tomato juice................................ .95 .45Tongue, beef ............................... .74 .38Tongue, calf................................. .79 .40Tongue, lamb............................... .76 .38Tongue, pork ............................... .74 .39Tongue, sheep............................. .69 .36Tripe, beef ................................... .83 .41Tripe, pickled ............................... .89 .43Trout ............................................ .82 .41Tuna ............................................ .76 .39Turkey.......................................... .67 .35Turnips ........................................ .93 .44Turtle ........................................... .84 .41Veal, carcass............................... .74 .38Veal, flank.................................... .65 .35Veal, loin...................................... .75 .38Veal, rib ....................................... .73 .37Veal, shank.................................. .77 .39Veal, quarter................................ .74 .38Venison ....................................... .78 .39Watercress .................................. .95 .45Watermelons ............................... .94 .45Whitefish ..................................... .76 .39Yams ........................................... .78 .39

74

SYSTEMDESIGN

Conversions

Table 33: ConversionsTo Convert Into Multiply by

AAcres sq. feet 43,560.0Atmospheres cms. of mercury 76.0Atmospheres ft. of water (at 4°C) 33.90Atmospheres in. of mercury (at 0°C) 29.92Atmospheres kgs./sq. cm. 1.0333Atmospheres pounds/sq. in. 14.70

BBarrels (U.S. liquid) gallons 31.5Barrels (oil) gallons (oil) 42.0Btu foot-lbs 778.3Btu grams-calories 252.0Btu horsepower-hrs. 3.931 x 10-4

Btu kilowatt-hrs 2.928 x 10-4

Btu/hr. horsepower 3.931 x 10-4

Btu/hr. watts 0.2931C

Calories, gram (mean) B.t.u. (mean) 3.9685 x 10-3

Centigrade Fahrenheit 9/5(C° + 40) -40Centimeters feet 3.281 x 10-2

Centimeters inches 0.3937Centimeters mils 393.7Centimeters of mercury atmospheres 0.01316Centimeters of mercury feet of water 0.4461Centimeters of mercury pounds/sq. in. 0.1934Circumference radians 6.283Cubic centimeters cu. feet 3.531 x 10-5

Cubic centimeters cu. inches 0.06102Cubic centimeters gallons (U.S. liq.) 2.642 x 10-4

Cubic feet cu. cms. 28,320.0Cubic feet cu. inches 1,728.0Cubic feet gallons (U.S. liq.) 7.481Cubic feet liters 28.32Cubic feet quarts (U.S. liq.) 29.92Cubic feet/min. gallons/sec. 0.1247Cubic feet/min. pounds of water/min. 62.43Cubic inches cu. cms. 16.39Cubic inches gallons 4.329 x 10-3

Cubic inches quarts (U.S. liq.) 0.01732Cubic meters cu. feet 35.31Cubic meters gallons (U.S. liq) 264.2Cubic yards cu. feet 27.0Cubic yards cu. meters 0.7646Cubic yards gallons (U.S. liq.) 202.0

DDegrees (angle) radians 0.01745Drams (apothecaries’ or troy) ounces (avoirdupois) 0.13714Drams (apothecaries’ or troy) ounces (troy) 0.125Drams (U.S. fluid or apothecary) cubic cm. 3.6967Drams grams 1.772Drams grains 27.3437Drams ounces 0.0625

FFahrenheit centigrade 5/9(F + 40) - 40Feet centimeters 30.48Feet kilometers 3.048 x 10-4

Feet meters 0.3048Feet miles (naut.) 1.645 x 10-4

Feet miles (stat.) 1.894 x 10-4

Feet of water atmospheres 0.02950Feet of water in. of mercury 0.8826Feet of water kgs./sq. cm. 0.03045Feet of water kgs./sq. meter 304.8Feet of water pounds/sq. ft. 62.43Feet of water pounds/sq. in. 0.4335Foot-pounds Btu 1.286 x 10-3

Foot-pounds gram-calories 0.3238Foot-pounds hp.-hrs. 5.050 x 10-7

Foot-pounds kilowatt-hrs. 3.766 x 10-7

Foot-pounds/min. Btu/min. 1.286 x 10-8

Foot-pounds/min. horsepower 3.030 x 10-5

Foot-pounds/sec. Btu/hr. 4.6263Furlongs miles 0.125

To Convert Into Multiply byFurlongs feet 660.0

GGallons cu. cms. 3,785.0Gallons cu. feet 0.1337Gallons cu. inches 231.0Gallons cu. meters 3.785 x 10-3

Gallons cu. yards 4.951 x 10-3

Gallons liters 3.785Gallons (liq. Br. Imp.) gallons (U.S. liq.) 1.20095Gallons (U.S.) gallons (Imp.) 0.83267Gallons of water pounds of water 8.3453Gallons/min. cu. ft./sec. 2.228 x 10-3

Gallons/min. liters/sec. 0.06308Gallons/min. cu. ft./hr. 8.0208Grains (troy) grains (avdp.) 1.0Grains (troy) grams 0.06480Grains (troy) ounces (avdp.) 0.286 x 10-3

Grains (troy) pennyweight (troy) 0.04167Grains/U.S. gal. parts/million 17.118Grains/U.S. gal. pounds/million gal. 142.86Grains/lmp. gal. parts/million 14.286Grams grains 15.43Grams ounces (avdp.) 0.03527Grams ounces (troy) 0.03215Grams poundals 0.07093Grams pounds 2.205 x 10-3

Grams/liter parts/million 1,000.0Gram-calories Btu 3.9683 x 10-3

Gram-caloories foot-pounds 3.0880Gram-calories kilowatt-hrs. 1.1630 x 10-4

Gram-calories watt-hrs. 1.1630 x 10-3

HHorsepower Btu/min. 42.40Horsepower foot-lbs./min. 33,000.Horsepower foot-lbs./sec. 550.0Horsepower (metric) horsepower 0.9863

(542.5 ft. lb./sec.) (550 ft. lb./sec.)Horsepower horsepower (metric) 1.014

(550 ft. lb./sec.) (542.5 ft. lb./sec.)Horsepower kilowatts 0.7457Horsepower watts 745.7Horsepower (boiler) Btu/hr. 33,520.Horsepower (boiler) kilowatts 9.803Horsepower-hrs. Btu 2,547.Horsepower-hrs. foot-lbs. 1.98 x 106

Horsepower-hrs. kilowatt-hrs. 0.7457I

Inches centimeters 2.540Inches meters 2.540 x 10-2

Inches millimeters 25.40Inches yards 2.778 x 10-2

Inches of mercury atmospheres 0.03342Inches of mercury feet of water 1.133Inches of mercury kgs./sq. cm. 0.03453Inches of mercury kgs./sq.meter 345.3Inches of mercury pounds/sq. ft. 70.73Inches of mercury pounds/sq. in. 0.4912Inches of water (at 4°C) atmospheres 2.458 x 10-3

Inches of water (at 4°C) inches of mercury 0.07355Inches of water (at 4°C) kgs./sq./ cm. 2.538 x 10-3

Inches of water (at 4°C) ounces/sq. in. 0.5781Inches of water (at 4°C) pounds/sq. ft. 5.204Inches of water (at 4°C) pounds/sq. in. 0.03613

JJoules Btu 9.480 x 10-4

KKilograms grams 1,000.0Kilograms pounds 2.205Kilograms/cu. meter pounds/cu. ft. 0.06243Kilograms/cu. meter pounds/cu. in. 3.613 x 10-5

Kilograms/sq. cm. atmospheres 0.9678Kilograms/sq. cm. feet of water 32.84

75

SYSTEMDESIGN

Conversions

Table 33: ConversionsTo Convert Into Multiply by

Kilograms/sq. cm. inches of mercury 28.96Kilograms/sq. cm. pounds/sq. ft. 2,048Kilograms/sq. cm. pounds/sq. in. 14.22Kilograms/sq. meter atmospheres 9.678 x 10-5

Kilograms/sq. meter feet of water 3.281 x 10-3

Kilograms/sq. meter inches of mercury 2.896 x 10-3

Kilograms/sq. meter pounds/sq. ft. 0.2048Kilograms/sq. meter pounds/sq. in. 1.422 x 10-3

Kilograms/sq. mm. kgs./sq. meter 106

Kilogram-calories Btu 3.968Kilogram-calories foot-pounds 3,088.Kilogram-calories hp-hrs. 1.560 x 10-3

Kilogram-calories kilowatt-hrs. 1.163 x 10-3

Kilogram meters Btu 9.294 x 10-3

Kilometers centimeters 105

Kilometers feet 3,281.Kilometers miles 0.6214Kilowatts Btu/min. 56.87Kilowatts foot-lbs/min. 4.426 x 104

Kilowatts foot-lbs/sec. 737.6Kilowatts horsepower 1.341Kilowatts watts 1,000.0Kilowatt-hrs Btu 3,413.Kilowatt-hrs. foot-lbs. 2.655 x 106

Kilowatt-hrs horsepower-hrs 1.341Knots statute miles/hr. 1.151

LLiters cu. cm. 1,000.0Liters cu. feet 0.03531Liters cu. inches 61.02Liters gallons (U.S. liq.) 0.2642

MMeters centimeters 100.0Meters feet 3.281Meters inches 39.37Meters millimeters 1,000.0Meters yards 1.094Microns inches 39.37 x 10-6

Microns meters 1 x 10-6

Miles (statute) feet 5.280.Miles (statute) kilometers 1.609Miles/hr. cms./sec. 44.70Miles/hr. feet/min. 88.Mils inches 0.001Mils yards 2.778 x 10-5

NNepers decibels 8.686

OOhms megohms 10-6

Ohms microhms 106

Ounces (avoirdupois) drams 16.0Ounces (avoirdupois) grains 437.5Ounces (avoirdupois grams 28.35Ounces (avoirdupois) pounds 0.0625Ounces (avoirdupois ounces (troy) 0.9115Ounces (troy) grains 480.0Ounces (troy) grains 31.10Ounces (troy) ounces (avdp.) 1.09714Ounces (troy) pounds (troy) 0.08333

PParts/million grains/U.S. gal. 0.0584Parts/million grains/lmp. gal 0.07016Parts/million pounds/million gal. 8.33Pounds (avoirdupois) ounces (troy) 14.58Pounds (avoirdupois) drams 256.Pounds (avoirdupois) grains 7,000.Pounds (avoirdupois) grams 453.59Pounds (avoirdupois) kilograms 0.454Pounds (avoirdupois) ounces 16.0Pounds (avoirdupois) tons (short) 0.0005

To Convert Into Multiply by

Pounds (troy) ounces (avdp.) 13.1657Pounds of water cu. feet 0.01602Pounds of water cu. inches 27.68Pounds of water gallons 0.1198Pounds of water/min. cu. ft/sec. 2.670 x 10-4

Pounds/cu. ft. grams/cu. cm. 0.01602Pounds/cu. ft. kgs./cu. meter 16.02Pounds/cu. ft. pounds/cu. in. 5.787 x 10-4

Pounds/cu. in. pounds/cu. ft. 1,728.Pounds/sq. ft. atmospheres 4.725 x 10-4

Pounds/sq. ft. feet of water 0.01602Pounds/sq. ft. inches of mercury 0.01414Pounds/sq. in. atmospheres 0.06804Pounds/sq. in. feet of water 2.307Pounds/sq. in. inches of mercury 2.036Pounds/sq. in. kgs./sq. meter 703.1Pounds/sq. in. pounds/sq. ft. 144.0

RRadians degrees 57.30Revolutions/min. degrees/sec. 6.0Revolutions/min. radians/sec. 0.1047Revolutions/min. revs./sec. 0.01667

SSquare centimeters sq. feet 1.076 x 10-3

Square centimeters sq. inches 0.1550Square centimeters sq. meters 0.0001Square centimeters sq. millimeters 100.0Square feet acres 2.296 x 10-5

Square feet sq. cms. 929.0Square feet sq. inches 144.0Square feet sq. miles 3.587 x 10-6

Square inches sq. cms. 6.452Square inches sq. feet 6.944 x 10-3

Square inches sq. yards 7.716 x 10-4

Square meters sq. feet 10.76Square meters sq. inches 1,550.Square meters sq. millimeters 106

Square meters sq. yards 1.196Square millimeters sq. inches 1.550 x 10-3

Square yards sq. feet 9.0Square yards sq. inches 1,296.Square yards sq. meters 0.8361

TTemperature (°C) + 273 absolute temperature (°C) 1.0Temperature (°C) + 17.78 temperature (°F) 1.8Temperature (°F) + 460 absolute temperature (°F) 1.0Temperature (°F) - 32 temperature (°C) 5/9Tons (long) kilograms 1,016.Tons (long) pounds 2,240.Tons (long) tons (short) 1.120Tons (metric) kilograms 1,000.Tons (metric) pounds 2,205.Tons (short) kilograms 907.2Tons (short) pounds 2,000.Tons (short) tons (long) 0.89287Tons of water/24 hrs. pounds of water/hr. 83.333Tons of water/24 hrs. gallons/min. 0.16643Tons of water/24 hrs. cu. ft./hr. 1.3349

WWatts Btu/hr. 3.4129Watts Btu/min. 0.05688Watts horsepower 1.341 x 10-3

Watts horsepower (metric) 1.360 x 10-3

Watts kilowatts 0.001Watts (Abs.) B.t.u. (mean)/min. 0.056884Watt-hours Btu 3.413Watt-hours horsepower-hrs. 1.341 x 10-3

YYards centimeters 91.44Yards kilometers 9.144 x 10-4

Yards meters 0.9144

76

SYSTEMDESIGN

Flow of Water through Schedule 40 Steel Pipe

Table 34: Flow of Water through Schedule 40 Steel PipePressure Drop per 1,000 Feet of Schedule 40 Steel Pipe, in pounds per square inch

Dschg Vel. Pres- Vel. Pres- Vel. Pres- Vel. Pres- Vel. Pres- Vel. Pres- Vel. Pres- Vel. Pres- Vel. Pres-Gals. Ft. per sure Ft. per sure Ft. per sure Ft. per sure Ft. per sue Ft. per sure Ft. per sure Ft. per sure Ft. per sure

per Min. Sec. Drop Sec. Drop Sec. Drop Sec. Drop Sec. Drop Sec. Drop Sec. Drop Sec. Drop Sec. Drop

1"1 .37 0.49 1-1/4"2 .74 1.70 0.43 .045 1-1/2"3 1.12 3.53 0.64 0.94 0.47 0.444 1.49 5.94 0.86 1.55 0.63 0.74 2"5 1.86 9.02 1.07 2.36 0.79 1.126 2.24 12.25 1.28 3.30 0.95 1.53 .57 0.46 2-1/2"8 2.98 21.1 1.72 5.52 1.26 2.63 .76 .075

10 3.72 30.8 2.14 8.34 1.57 3.86 .96 1.14 .67 0.4815 5.60 64.6 3.21 17.6 2.36 8.13 1.43 2.33 1.00 0.99 3" 3-1/2"20 7.44 110.5 4.29 29.1 3.15 13.5 1.91 3.86 1.34 1.64 .87 0.5925 5.36 43.7 3.94 20.2 2.39 5.81 1.68 2.48 1.08 0.67 .81 0.42 4"30 6.43 62.9 4.72 29.1 2.87 8.04 2.01 3.43 1.30 1.21 .97 0.6035 7.51 82.5 5.51 38.2 3.35 10.95 2.35 4.49 1.52 1.58 1.14 0.79 .88 0.4240 6.30 47.8 3.82 13.7 2.68 5.88 1.74 2.06 1.30 1.00 1.01 0.5345 7.08 60.6 4.30 17.4 3.00 7.14 1.95 2.51 1.46 1.21 1.13 0.6750 7.87 74.7 4.78 20.6 3.35 8.82 2.17 3.10 1.62 1.44 1.26 0.80 5"60 5.74 29.6 4.02 12.2 2.60 4.29 1.95 2.07 1.51 1.1070 6.69 38.6 4.69 15.3 3.04 5.84 2.27 2.71 1.76 1.50 1.12 0.4880 6" 7.65 50.3 5.37 21.7 3.48 7.62 2.59 3.53 2.01 1.87 1.28 0.6390 8.60 63.6 6.04 26.1 3.91 9.22 2.92 4.46 2.26 2.37 1.44 0.80

100 1.11 0.39 9.56 75.1 6.71 32.3 4.34 11.4 3.24 5.27 2.52 2.81 1.60 0.95125 1.39 0.56 8.38 48.2 5.42 17.1 4.05 7.86 3.15 4.38 2.00 1.48150 1.67 0.78 10.06 60.4 6.51 23.5 4.86 11.3 3.78 6.02 2.41 2.04175 1.94 1.06 8" 11.73 90.0 7.59 32.0 5.67 14.7 4.41 8.20 2.81 2.78200 2.22 1.32 8.68 39.7 6.48 19.2 5.04 10.2 3.21 3.46225 2.50 1.66 1.44 0.44 9.77 50.2 7.29 23.1 5.67 12.9 3.61 4.37250 2.78 2.05 1.60 0.55 10.85 61.9 8.10 28.5 6.30 15.9 4.01 5.14275 3.06 2.36 1.76 0.63 11.94 75.0 8.91 34.4 6.93 18.3 4.41 6.22300 3.33 2.80 1.92 0.75 13.02 84.7 9.72 40.9 7.56 21.8 4.81 7.41325 3.61 3.29 2.08 0.88 10.53 45.5 8.18 25.5 5.21 8.25350 3.89 3.62 2.24 0.97 11.35 52.7 8.82 29.7 5.61 9.57375 4.16 4.16 2.40 1.11 12.17 60.7 9.45 32.3 6.01 11.0400 4.44 4.72 2.56 1.27 12.97 68.9 10.08 36.7 6.41 12.5425 4.72 5.34 2.72 1.43 10" 13.78 77.8 10.70 41.5 6.82 14.1450 5.00 5.96 2.88 1.60 14.59 87.3 11.33 46.5 7.22 15.0475 5.27 6.66 3.04 1.69 1.93 0.30 11.96 51.7 7.62 16.7500 5.55 7.39 3.20 1.87 2.04 0.63 12.59 57.3 8.02 18.5550 6.11 8.94 3.53 2.26 2.24 0.70 13.84 69.3 8.82 22.4600 6.66 10.6 3.85 2.70 2.44 0.86 12" 15.10 82.5 9.62 26.7650 7.21 11.8 4.17 3.16 2.65 1.01 10.42 31.3700 7.77 13.7 4.49 3.69 2.85 1.18 2.01 0.48 11.22 36.3750 8.32 15.7 4.81 4.21 3.05 1.35 2.15 0.55 14" 12.02 41.6800 8.88 17.8 5.13 4.79 3.26 1.54 2.29 0.62 12.82 44.7850 9.44 20.2 5.45 5.11 3.46 1.74 2.44 0.70 2.02 0.43 13.62 50.5900 10.00 22.6 5.77 5.73 3.66 1.94 2.58 0.79 2.14 0.48 14.42 56.6950 10.55 23.7 6.09 6.38 3.87 2.23 2.72 0.88 2.25 0.53 15.22 63.1

1,000 11.10 26.3 6.41 7.08 4.07 2.40 2.87 0.98 2.38 0.59 16" 16.02 70.01,100 12.22 31.8 7.05 8.56 4.48 2.74 3.16 1.18 2.61 0.68 17.63 84.61,200 13.32 37.8 7.69 10.2 4.88 3.27 3.45 1.40 2.85 0.81 2.18 0.401,300 14.43 44.4 8.33 11.3 5.29 3.86 3.73 1.56 3.09 0.95 2.36 0.471,400 15.54 51.5 8.97 13.0 5.70 4.44 4.02 1.80 3.32 1.10 2.54 0.541,500 16.65 55.5 9.62 15.0 6.10 5.11 4.30 2.07 3.55 1.19 2.73 0.62 18"1,600 17.76 63.1 10.26 17.0 6.51 5.46 4.59 2.36 3.80 1.35 2.91 0.711,800 19.98 79.8 11.54 21.6 7.32 6.91 5.16 2.98 4.27 1.71 3.27 0.85 2.58 0.482,000 22.20 98.5 12.83 25.0 8.13 8.54 5.73 3.47 4.74 2.11 3.63 1.05 2.88 0.562,500 16.03 39.0 10.18 12.5 7.17 5.41 5.92 3.09 4.54 1.63 3.59 0.88 20"3,000 19.24 52.4 12.21 18.0 8.60 7.31 7.12 4.45 5.45 2.21 4.31 1.27 3.45 0.73 24"3,500 22.43 71.4 14.25 22.9 10.03 9.95 8.32 6.18 6.35 3.00 5.03 1.52 4.03 0.944,000 25.65 93.3 16.28 29.9 11.48 13.0 9.49 7.92 7.25 3.92 5.74 2.12 4.61 1.22 3.19 0.514,500 18.31 37.8 12.90 15.4 10.67 9.36 8.17 4.97 6.47 2.50 5.19 1.55 3.59 0.605,000 20.35 46.7 14.34 18.9 11.84 11.6 9.08 5.72 7.17 3.08 5.76 1.78 3.99 0.746,000 24.42 67.2 17.21 27.3 14.32 15.4 10.88 8.24 8.62 4.45 6.92 2.57 4.80 1.007,000 28.50 85.1 20.08 37.2 16.60 21.0 12.69 12.2 10.04 6.06 8.06 3.50 5.68 1.368,000 22.95 45.1 18.98 27.4 14.52 13.6 11.48 7.34 9.23 4.57 6.38 1.789,000 25.80 57.0 21.35 34.7 16.32 17.2 12.92 9.20 10.37 5.36 7.19 2.25

10,000 28.63 70.4 23.75 42.9 18.16 21.2 14.37 11.5 11.53 6.63 7.96 2.7812,000 34.38 93.6 28.50 61.8 21.80 30.9 17.23 16.5 13.83 9.54 9.57 3.7114,000 33.20 84.0 25.42 41.6 20.10 20.7 16.14 12.0 11.18 5.0516,000 29.05 54.4 22.96 27.1 18.43 15.7 12.77 6.60

77

SYSTEMDESIGN

Friction Loss for Water in Feet per 100 ft. Schedule 40 Steel Pipe

Table 35: Friction Loss* for Water in Feet per 100 ft. Schedule 40 Steel PipeU.S. Velocity hf

Gal/Min. Ft/Sec. Friction

3/8" PIPE1.4 2.35 9.031.6 2.68 11.61.8 3.02 14.32.0 3.36 17.32.5 4.20 26.03.0 5.04 36.03.5 5.88 49.04.0 6.72 63.25.0 8.40 96.16 10.08 1367 11.8 1828 13.4 2369 15.1 297

10 16.8 364

1/2" PIPE2 2.11 5.502.5 2.64 8.243 3.17 11.53.5 3.70 15.34.0 4.22 19.75 5.28 29.76 6.34 42.07 7.39 56.08 8.45 72.19 9.50 90.1

10 10.56 110.612 12.7 15614 14.8 21116 16.9 270

3/4" PIPE4.0 2.41 4.855 3.01 7.276 3.61 10.27 4.21 13.68 4.81 17.39 5.42 21.6

10 6.02 26.512 7.22 37.514 8.42 50.016 9.63 64.818 10.8 80.920 12.0 99.022 13.2 12024 14.4 14126 15.6 16528 16.8 189

1" PIPE6 2.23 3.168 2.97 5.20

10 3.71 7.9012 4.45 11.114 5.20 14.716 5.94 19.018 6.68 23.720 7.42 28.922 8.17 34.824 8.91 41.026 9.65 47.828 10.39 55.130 11.1 62.935 13.0 84.440 14.8 10945 16.7 13750 18.6 168

* Aging Factor Included

U.S. Velocity hfGal/Min. Ft/Sec. Friction

1-1/4" PIPE12 2.57 2.8514 3.00 3.7716 3.43 4.8318 3.86 6.0020 4.29 7.3022 4.72 8.7224 5.15 10.2726 5.58 11.9428 6.01 13.730 6.44 15.635 7.51 21.940 8.58 27.145 9.65 33.850 10.7 41.455 11.8 49.760 12.9 58.665 13.9 68.670 15.0 79.275 16.1 90.6

1-1/2" PIPE16 2.52 2.2618 2.84 2.7920 3.15 3.3822 3.47 4.0524 3.78 4.7626 4.10 5.5428 4.41 6.3430 4.73 7.2035 5.51 9.6340 6.30 12.4145 7.04 15.4950 7.88 18.955 8.67 22.760 9.46 26.765 10.24 31.270 11.03 36.075 11.8 41.280 12.6 46.685 13.4 52.490 14.2 58.795 15.0 65.0

100 15.8 71.6

2" PIPE25 2.39 1.4830 2.87 2.1035 3.35 2.7940 3.82 3.5745 4.30 4.4050 4.78 5.3760 5.74 7.5870 6.69 10.280 7.65 13.190 8.60 16.3

100 9.56 20.0120 11.5 28.5140 13.4 38.2160 15.3 49.5

2-1/2" PIPE35 2.35 1.1540 2.68 1.4745 3.02 1.8450 3.35 2.2360 4.02 3.1370 4.69 4.1880 5.36 5.3690 6.03 6.69

100 6.70 8.18120 8.04 11.5140 9.38 15.5160 10.7 20.0180 12.1 25.2200 13.4 30.7220 14.7 37.1240 16.1 43.8

U.S. Velocity hfGal/Min. Ft/Sec. Friction

3" PIPE50 2.17 .76260 2.60 1.0670 3.04 1.4080 3.47 1.8190 3.91 2.26

100 4.34 2.75120 5.21 3.88140 6.08 5.19160 6.94 6.68180 7.81 8.38200 8.68 10.2220 9.55 12.3240 10.4 14.5260 11.3 16.9280 12.2 19.5300 13.0 22.1350 15.2 30

4" PIPE100 2.52 .718120 3.02 1.01140 3.53 1.35160 4.03 1.71180 4.54 2.14200 5.04 2.61220 5.54 3.13240 6.05 3.70260 6.55 4.30280 7.06 4.95300 7.56 5.63350 8.82 7.54400 10.10 9.75450 11.4 12.3500 12.6 14.4550 13.9 18.1600 15.1 21.4

5" PIPE160 2.57 .557180 2.89 .698200 3.21 .847220 3.53 1.01240 3.85 1.19260 4.17 1.38300 4.81 1.82350 5.61 2.43400 6.41 3.13450 7.22 3.92500 8.02 4.79600 9.62 6.77700 11.2 9.13800 12.8 11.8900 14.4 14.8

1000 16.0 18.2

6" PIPE220 2.44 .411240 2.66 .482260 2.89 .560300 3.33 .733350 3.89 .980400 4.44 1.25450 5.00 1.56500 5.55 1.91600 6.66 2.69700 7.77 3.60800 8.88 4.64900 9.99 5.81

1000 11.1 7.101100 12.2 8.521200 13.3 10.11300 14.4 11.71400 15.5 13.6

78

SYSTEMDESIGN

Moisture Content of Air

Figure 68: Ashrae Psychrometric Chart No. 1

79

SYSTEMDESIGN

Friction Head Loss for Water

Table 36: Equivalent Length in Feet of New Straight Pipe for Valves and Fittings for Turbulent Flow OnlyPipe Size

1/4 3/8 1/2 3/4 1 11/4 11/2 2 21/2 3 4 5 6 8 10 12 14 16 18 20 24

2.3 3.1 3.6 4.4 5.2 6.6 7.4 8.5 9.3 11 139.0 11

.92 1.2 1.6 2.1 2.4 3.1 3.6 4.4 5.9 7.3 8.9 12 14 17 18 21 23 25 303.6 4.8 7.2 9.8 12 15 17 19 22 24 28

1.5 2.0 2.2 2.3 2.7 3.2 3.4 3.6 3.6 4.0 4.63.3 3.7

1.1 1.3 1.6 2.0 2.3 2.7 2.9 3.4 4.2 5.0 5.7 7.0 8.0 9.0 9.4 10 11 12 142.8 3.4 4.7 5.7 6.8 7.8 8.6 9.6 11 11 13

.34 .52 .71 .92 1.3 1.7 2.1 2.7 3.2 4.0 5.53.3 4.5

.45 .59 .81 1.1 1.3 1.7 2.0 2.6 3.5 4.5 5.6 7.7 9.0 11 13 15 16 18 222.1 2.9 4.5 6.3 8.1 9.7 12 13 15 17 20

.79 1.2 1.7 2.4 3.2 4.6 5.6 7.7 9.3 12 179.9 14

.69 .82 1.0 1.3 1.5 1.8 1.9 2.2 2.8 3.3 3.8 4.7 5.2 6.0 6.4 7.2 7.6 8.2 9.61.9 2.2 3.1 3.9 4.6 5.2 5.9 6.5 7.2 7.7 8.8

2.4 3.5 4.2 5.3 6.6 8.7 9.9 12 13 17 2114 17

2.0 2.6 3.3 4.4 5.2 6.6 7.5 9.4 12 15 18 24 30 34 37 43 47 52 627.7 10 15 20 25 30 35 39 44 49 57

2.3 3.1 3.6 4.4 5.2 6.6 7.4 8.5 9.3 11 139.0 11

.92 1.2 1.6 2.1 2.4 3.1 3.6 4.4 5.9 7.3 8.9 12 14 17 19 21 23 25 303.6 4.8 7.2 9.8 12 15 17 19 22 24 28

1.1 1.3 1..6 2.0 2.3 2.7 2.9 3.4 4.2 5.0 5.7 7.0 8.0 9.0 9.4 10 11 12 142.8 3.4 4.7 5.7 6.8 7.8 8.6 9.6 11 11 13

21 22 22 24 29 37 42 54 62 79 11065 86

38 40 45 54 59 70 77 94 120 150 190 260 310 39077 99 150 210 270 330

.32 .45 .56 .67 .84 1.1 1.2 1.5 1.7 1.9 2.51.6 2.0

2.6 2.7 2.8 2.9 3.1 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.22.3 2.4 2.6 2.7 2.8 2.9 2.9 3.0 3.0 3.0 3.0

12.8 15 15 15 17 18 18 18 18 18 1815 15

15 15 17 18 18 21 22 28 38 50 63 90 120 140 160 190 210 240 30023 31 52 74 98 120 150 170 200 230 280

7.2 7.3 8.0 8.8 11 13 15 19 22 27 3822 31

3.8 5.3 7.2 10 12 17 21 27 38 50 63 90 120 14022 31 52 74 98 120

.14 .18 .21 .24 .29 .36 .39 .45 .47 .53 .65.44 .52

.04 .07 .10 .13 .18 .26 .31 .43 .52 .67 .95 1.3 1.6 2.3 2.9 3.5 4.0 4.7 5.3 6.1 7.6.55 .77 1.3 1.9 2.4 3.0 3.6 4.3 5.0 5.7 7.0

.44 .68 .96 1.3 1.8 2.6 3.1 4.3 5.2 6.7 9.5 13 16 23 29 35 40 47 53 61 765.5 7.7 13 19 24 30 36 43 50 57 70

.88 1.4 1.9 2.6 3.6 5.1 6.2 8.5 10 13 19 25 32 45 58 70 80 95 110 120 15011 15 26 37 49 61 73 86 100 110 140

4.6 5.0 6.6 7.7 18 20 27 29 34 42 53 61

h = (V1 - V2)2 FEET OF LIQUID; IF V2 = 0 h = V12

FEET OF LIQUID2g 2g

Reprinted from the STANDARDS OF THE HYDRAULIC INSTITUTE, Eleventh Edition.Copyright 1965 by the Hydraulic Institute, 122 East 42nd Street, New York, New York 10017.

Fittings

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

Reg. SteelFlanged C.I.

Long Rad SteelFlanged C.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

FlangedSteelC.I.

ScrewedSteelC.I.

Bell Mouth SteelInlet C.I.

Square SteelMouth Inlet C.I.

Re-entrant SteelPipe C.I.

Y-Strainer

SuddenEnlarge-

ment

Regular90° ELL

Long Radius90° ELL

Regular45° ELL

Tee- LineFlow

Tee- BranchFlow

180°ReturnBend

Globe Valve

Gate Valve

Angle Valve

Swing CheckValve

Couplingor Union

80

SYSTEMDESIGN

ANSI Flange Standards

Table 37: ANSI Flange StandardsAll Dimensions are in Inches

Pipe Size 1/2 3/4 1 11/4 11/2 2 21/2 3 31/2 4 5 6 8 10 12125 lb CAST IRON – ANSIDiameter of Flange – – 41/4 45/8 5 6 7 71/2 81/2 9 10 11 131/2 16 19Thickness of Flange (min)1 – – 7/16

1/29/16

5/811/16

3/413/16

15/1615/16 1 11/8 13/16 11/4

Diameter of Bolt Circle – – 31/8 31/2 37/8 43/4 51/2 6 7 71/2 81/2 91/2 113/4 141/4 17Number of Bolts – – 4 4 4 4 4 4 8 8 8 8 8 12 12Diameter of Bolts – – 1/2

1/21/2

5/85/8

5/85/8

5/83/4

3/43/4

7/87/8

1 125 lb flanges have plain faces.

250 lb CAST IRON – ANSIDiameter of Flange – – 47/8 51/4 61/8 61/2 71/2 81/4 9 10 11 121/2 15 171/2 201/2

Thickness of Flange (min)2 – – 11/163/4

13/167/8 1 11/8 13/16 11/4 13/8 17/16 15/8 17/8 2

Diameter of Raised Face – – 211/16 31/16 39/16 43/16 415/16 511/16 65/16 615/16 85/16 911/16 1115/16 141/16 167/16

Diameter of Bolt Circle – – 31/2 37/8 41/2 5 57/8 65/8 71/4 77/8 91/4 105/8 13 151/4 173/4

Number of Bolts – – 4 4 4 8 8 8 8 8 8 12 12 16 16Diameter of Bolts – – 5/8

5/83/4

5/83/4

3/43/4

3/43/4

3/47/8 1 11/8

2 250 lb flanges have a 1/16” raised face which is included in the flange thickness dimensions.

150 lb BRONZE – ANSIDiameter of Flange 31/2 37/8 41/4 45/8 5 6 7 71/2 81/2 9 10 11 131/2 16 19Thickness of Flange (min)3 5/16

11/323/8

13/327/16

1/29/16

5/811/16

11/163/4

13/1615/16 1 11/16

Diameter of Bolt Circle 23/8 23/4 31/8 31/2 37/8 43/4 51/2 6 7 71/2 81/2 91/2 113/4 141/4 17Number of Bolts 4 4 4 4 4 4 4 4 8 8 8 8 8 12 12Diameter of Bolts 1/2

1/21/2

1/21/2

5/85/8

5/85/8

5/83/4

3/43/4

7/87/8

3 150 lb bronze flanges have plain faces with two concentric gasket-retaining grooves between the port and the bolt holes.

300 lb BRONZE – ANSIDiameter of Flange 33/4 45/8 47/8 51/4 61/8 61/2 71/2 81/4 9 10 11 121/2 15 – –Thickness of Flange (min)4 1/2

17/3219/32

5/811/16

3/413/16

29/3231/32 11/16 11/8 13/16 13/8 – –

Diameter of Bolt Circle 25/8 31/4 31/2 37/8 41/2 5 57/8 65/8 71/4 77/8 91/4 105/8 13 – –Number of Bolts 4 4 4 4 4 8 8 8 8 8 8 12 12 – –Diameter of Bolts 1/2

5/85/8

5/83/4

5/83/4

3/43/4

3/43/4

3/47/8 – –

4 300 lb bronze flanges have plain faces with two concentric gasket-retaining grooves between the port and the bolt holes.

150 lb STEEL – ANSIDiameter of Flange 31/2 37/8 41/4 45/8 5 6 7 71/2 81/2 9 10 11 131/2 16 19Thickness of Flange (min)5 – – 7/16

1/29/16

5/811/16

3/413/16

15/1615/16 1 11/8 13/16 11/4

Diameter of Raised Face 13/8 111/16 2 21/2 27/8 35/8 41/8 5 51/2 63/16 75/16 81/2 105/8 123/4 15Diameter of Bolt Circle 23/8 23/4 31/8 31/2 37/8 43/4 51/2 6 7 71/2 81/2 91/2 113/4 141/4 17Number of Bolts 4 4 4 4 4 4 4 4 8 8 8 8 8 12 12Diameter of Bolts 1/2

1/21/2

1/21/2

5/85/8

5/85/8

5/83/4

3/43/4

7/87/8

5 150 lb steel flanges have a 1/16”raised face which is included in the flange thickness dimensions.

300 lb STEEL – ANSIDiameter of Flange 33/4 45/8 47/8 51/4 61/8 61/2 71/2 81/4 9 10 11 121/2 15 171/2 201/2

Thickness of Flange (min)6 – – 11/163/4

13/167/8 1 11/8 13/16 11/4 13/8 17/16 15/8 17/8 2

Diameter of Raised Face 13/8 111/16 2 21/2 2-7/8 35/8 41/8 5 51/2 63/16 75/16 81/2 105/8 123/4 15Diameter of Bolt Circle 25/8 31/4 31/2 37/8 41/2 5 57/8 65/8 71/4 77/8 91/4 105/8 13 151/4 173/4

Number of Bolts 4 4 4 4 4 8 8 8 8 8 8 12 12 16 16Diameter of Bolts 1/2

5/85/8

5/83/4

5/83/4

3/43/4

3/43/4

3/47/8 1 11/8

6 300 lb steel flanges have a 1/16” raised face which is included in the flange thickness dimensions.

400 lb STEEL – ANSIDiameter of Flange 33/4 45/8 47/8 51/4 61/8 61/2 71/2 81/4 9 10 11 121/2 15 171/2 201/2

Thickness of Flange (min)7 9/165/8

11/1613/16

7/8 1 11/8 11/4 13/8 13/8 11/2 15/8 17/8 21/8 21/4

Diameter of Raised Face 13/8 111/16 2 21/2 27/8 35/8 41/8 5 51/2 63/16 75/16 81/2 105/8 123/4 15Diameter of Bolt Circle 25/8 31/4 31/2 37/8 41/2 5 57/8 65/8 71/4 77/8 91/4 105/8 13 151/4 173/4

Number of Bolts 4 4 4 4 4 8 8 8 8 8 8 12 12 16 16Diameter of Bolts 1/2

5/85/8

5/83/4

5/83/4

3/47/8

7/87/8

7/8 1 11/8 11/4

7 400 lb steel flanges have a 1/4” raised face which is NOT included in the flange thickness dimensions.

600 lb STEEL – ANSIDiameter of Flange 33/4 45/8 47/8 51/4 61/8 61/2 71/2 81/4 9 103/4 13 14 161/2 20 22Thickness of Flange (min)8 9/16

5/811/16 13/16

7/8 1 11/8 11/4 13/8 11/2 13/4 17/8 23/16 21/2 25/8

Diameter of Raised Face 13/8 111/16 2 21/2 27/8 35/8 41/8 5 51/2 63/16 75/16 81/2 105/8 123/4 15Diameter ofBolt Circle 25/8 31/4 31/2 37/8 41/2 5 57/8 65/8 71/4 81/2 101/2 111/2 133/4 17 191/4

Number of Bolts 4 4 4 4 4 8 8 8 8 8 8 12 12 16 20Diameter of Bolts 1/2

5/85/8

5/83/4

5/83/4

3/47/8

7/8 1 1 11/8 11/4 11/4

8 600 lb steel flanges have a 1/4” raised face which is NOT included in the flange thickness dimensions.

81

SYSTEMDESIGN

Pipe Dimensions

Table 38: Schedule 40 Pipe DimensionsLength of Pipe

Diameters Transverse Areas per Sq. Foot of NumberNominal External Internal Cubic Feet Weight Threads

Size External Internal Thickness External Internal Metal Surface Surface per Foot per Foot per InchInches Inches Inches Inches Sq. Ins. Sq. Ins. Sq. Ins. Feet Feet of Pipe Pounds of Screw

1/8 .405 .269 .068 .129 .057 .072 9.431 14.199 .00039 .244 271/4 .540 .364 .088 .229 .104 .125 7.073 10.493 .00072 .424 183/8 .675 .493 .091 .358 .191 .167 5.658 7.747 .00133 .567 181/2 .840 .622 .109 .554 .304 .250 4.547 6.141 .00211 .850 143/4 1.050 .824 .113 .866 .533 .333 3.637 4.635 .00370 1.130 141 1.315 1.049 .133 1.358 .864 .494 2.904 3.641 .00600 1.678 111/2

11/4 1.660 1.380 .140 2.164 1.495 .669 2.301 2.767 .01039 2.272 111/2

11/2 1.900 1.610 .145 2.835 2.036 .799 2.010 2.372 .01414 2.717 111/2

2 2.375 2.067 .154 4.430 3.355 1.075 1.608 1.847 .02330 3.652 111/2

21/2 2.875 2.469 .203 6.492 4.788 1.704 1.328 1.547 .03325 5.793 83 3.500 3.068 .216 9.621 7.393 2.228 1.091 1.245 .05134 7.575 8

31/2 4.000 3.548 .226 12.56 9.886 2.680 .954 1.076 .06866 9.109 84 4.500 4.026 .237 15.90 12.73 3.174 .848 .948 .08840 10.790 85 5.563 5.047 .258 24.30 20.00 4.300 .686 .756 .1389 14.61 86 6.625 6.065 .280 34.47 28.89 5.581 .576 .629 .2006 18.97 88 8.625 7.981 .322 58.42 50.02 8.399 .442 .478 .3552 28.55 810 10.750 10.020 .365 90.76 78.85 11.90 .355 .381 .5476 40.48 812 12.750 11.938 .406 127.64 111.9 15.74 .299 .318 .7763 53.614 14.000 13.125 .437 153.94 135.3 18.64 .272 .280 .9354 63.016 16.000 15.000 .500 201.05 176.7 24.35 .238 .254 1.223 78.018 18.000 16.874 .563 254.85 224.0 30.85 .212 .226 1.555 105.020 20.000 18.814 .593 314.15 278.0 36.15 .191 .203 1.926 123.024 24.000 22.626 .687 452.40 402.1 50.30 .159 .169 2.793 171.0

Table 39: Schedule 80 Pipe DimensionsLength of Pipe

Diameters Transverse Areas per Sq. Foot of NumberNominal External Internal Cubic Feet Weight Threads

Size External Internal Thickness External Internal Metal Surface Surface per Foot per Foot per InchInches Inches Inches Inches Sq. Ins. Sq. Ins. Sq. Ins. Feet Feet of Pipe Pounds of Screw

1/8 .405 .215 .095 .129 .036 .093 9.431 17.750 .00025 .314 271/4 .540 .302 .119 .229 .072 .157 7.073 12.650 .00050 .535 183/8 .675 .423 .126 .358 .141 .217 5.658 9.030 .00098 .738 181/2 .840 .546 .147 .554 .234 .320 4.547 7.000 .00163 1.00 143/4 1.050 .742 1.54 .866 .433 .433 3.637 5.15 .00300 1.47 141 1.315 .957 .179 1.358 .719 .639 2.904 3.995 .00500 2.17 111/2

11/4 1.660 1.278 .191 2.164 1.283 .881 2.301 2.990 .00891 3.00 111/2

11/2 1.900 1.500 .200 2.835 1.767 1.068 2.010 2.542 .01227 3.65 111/2

2 2.375 1.939 .218 4.430 2.953 1.477 1.608 1.970 .02051 5.02 111/2

21/2 2.875 2.323 .276 6.492 4.238 2.254 1.328 1.645 .02943 7.66 83 3.500 2.900 .300 9.621 6.605 3.016 1.091 1.317 .04587 10.3 8

31/2 4.000 3.364 .318 12.56 8.888 3.678 .954 1.135 .06172 12.5 84 4.500 3.826 .337 15.90 11.497 4.407 .848 .995 .0798 14.9 85 5.563 4.813 .375 24.30 18.194 6.112 .686 .792 .1263 20.8 86 6.625 5.761 .432 34.47 26.067 8.300 .576 .673 .1810 28.6 88 8.625 7.625 .500 58.42 45.663 12.76 .442 .501 .3171 43.4 810 10.750 9.564 .593 90.76 71.84 18.92 .355 .400 .4989 64.4 812 12.750 11.376 .687 127.64 101.64 26.00 .299 .336 .7058 88.614 14.000 12.500 .750 153.94 122.72 31.22 .272 .306 .8522 107.016 16.000 14.314 .843 201.05 160.92 40.13 .238 .263 1.117 137.018 18.000 16.126 .937 254.85 204.24 50.61 .212 .237 1.418 171.020 20.000 17.938 1.031 314.15 252.72 61.43 .191 .208 1.755 209.024 24.000 21.564 1.218 452.40 365.22 87.18 .159 .177 2.536 297.0

82

HOOK-UPAPPLICATION

DIAGRAMS

Section 2

HOOK-UP DIAGRAMS

84

Boiler Steam Headers provide collect-ing vessels for the steam flowing fromone or more boilers, and distribute it toas many mains as are needed to sup-ply the plant. Often the flow may be ineither direction along the headerdepending on which boilers and whichsupply lines are being used. Selectingthe ideal location for the drip point isthus complicated. It is recommendedto make the header of such an

Figure II-1Boiler Steam Header

To Plant

Spira-tecLoss

Detector

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Figure II-2Draining End of Low Pressure Steam Main

FromBoiler

Spira-tecLoss

Detector

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

Strainer

CondensateReturn

In the case of low pressure mains,the use of Float and Thermostatictraps is recommended for the dripstations. The introduction of F & Ttraps with steel bodies, third gen-eration capsule type or bimetallicair vents, and operating mecha-nisms suitable for pressures up to465 psi, means that F & T trapscan also be used on properlydrained lines where waterhammerdoes not occur, even at pressureswhich would formerly have exclud-ed them. An auxiliary air vent isrecommended for the end of allmains where the system is startedup automatically.

LP Steam Main

increased diameter as to drop thesteam velocity through it to a low valueeven with maximum flow in eitherdirection.The header can then act alsoas a separator, and generously sizedsteam traps can be fitted at each end.The boiler header and the separator,which should be fitted in the steamtake off from modern high perfor-mance packaged boilers, maysometimes have to cope with carry-

over from the boiler. These two loca-tions form the exception to the generalrule that mains drip points rarely needa steam trap as large as the 1/2" sizeand can usually be fitted with 1/2" LowCapacity traps. Instead, traps in 3/4"and even 1" sizes are often used. Thepotential for steam losses when theselarger traps eventually become worn isincreased, and the use of Spira-tecsteam trap monitors is especially valid.

SupervisedStart-up

Valve

SupervisedStart-up

Valve

85

HOOK-UP DIAGRAMS

Drip points along the run of the steamlines, and at the bottom of any risers,should incorporate large diametercollecting pockets. Equal tees areuseful in sizes up through 6" and larg-er size pipes can have pockets 2 or 3sizes smaller than the main but notless than 6". The terminal points ofthe mains should have automatic airvents, and equal tees again provideconvenient collecting pockets for bothcondensate and air when installed asshown.

Figure II-3Draining and Air Venting Steam Lines

InvertedBucket

Steam Trapwith Integral

Strainer

Spira-tecLoss

Detector

BalancedPressure

ThermostaticAir Vent

Condensate Main

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Spira-tecLoss Detector

Figure II-4Draining Expansion Loops

Condensate Return

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Thermo-DynamicSteamTrap

Spira-tecLoss

Detector

Spira-tecLoss

Detector

Expansion loops are often fitted inthe vertical plane, with the loop eitherbelow or above the line. When belowthe line, condensate can collect in thebottom of the loop. Above the line, itwill collect just in front of the loop, atthe foot of the riser. Drainage pointsare necessary in each case, asshown.

SupervisedStart-up

Valve

SupervisedStart-up

Valve

Strainer

86

HOOK-UP DIAGRAMS

Both HP and LP mains often must bedrained to a condensate return line atthe same elevation as the steam line.The best location for the traps is thenbelow the steam line, with a riserafter the trap to the top of the returnline.

Figure II-5Draining Steam Mains to Return Main at Same Level

Spira-tecLoss

Detector

Thermo-DynamicSteam Trap withIntegral Strainer

Connector

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss

Detector

CondensateMainHP

MainLP

Main

For supervised startup of steammains, a manual bypass is fitted sothat condensate can be drained bygravity while the line pressure is toolow for it to be handled by the trap atan adequate rate. If a second trap isfitted in the bypass line, a similarhookup is obtained which is suitablefor automatic startup.

Figure II-6Trapping Hook-up for Start-up of Steam Main

Often the normal trap discharges to areturn line at higher elevation. Thestartup trap must always dischargeby gravity so here it is separated fromthe “normal running” trap. AThermoton is used so that it will closeautomatically when the condensatetemperature shows that warm up ofthe main is nearing completion.

Figure II-7Hook-up with Condensate Return Line at High Level

Thermo-DynamicSteam Trapwith Integral

Strainer

Spira-tecLoss

Detector

Thermo-Dynamic SteamTrap with Integral Strainer

Spira-tecLoss

Detector

Thermo-DynamicSteam Trapwith Integral

Strainer

Spira-tecLoss

Detector

Liquid ExpansionSteam Trap

Drain

CondensateReturn

CheckValve

CheckValve

SupervisedStart-up

Valve

CheckValve

SupervisedStart-up

Valve

87

HOOK-UP DIAGRAMS

In some cases, the existence of other service or processlines alongside the stream main is combined with theneed to lift the condensate from the drip point to higherlevel. Without the loop seal, clearance of condensate fromlength L and replacement with steam means that forappreciable times steam passes up length H and holdsthe trap closed, although condensate may be collecting inthe pocket. The arrangement shown minimizes this prob-lem and gives most consistent performance of the trap.

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Spira-tecLoss

Detector

Figure II-8Draining Steam Main where Trapmust be at Higher Level

SteamMain

GenerousCollecting

Pocket

Loop Seal(where “L”

exceeds “H”)

CondensateMain

L

H

Figure II-9Condensate Drainage to Reinforced Plastic Return Line, with Overheat Protection

Steam Main

CondensateReturn Pipe

CoolingChamber

Diffuser

Spira-tecLoss

Detector

Main DripSteam Trap

HighTemperature

Drain

T44 Temperature Control(set to open at temperature

limit of pipe)On some extended sites,steam distribution is under-ground and drip points areinside “steam pits”. Steammain drip traps should dis-charge into gravity returnsystems, but at times it may benecessary to connect themdirectly to a pumped conden-sate line. To avoid failure ofplastic or fiberglass pipingcaused by high temperaturefrom steam leakage wheneventually the trap becomesworn, a cooling chamber andcontrol as shown can be used.If the temperature of the con-densate leaving the chamberever reaches the safe limit, thecontrol valve opens.Condensate is dischargedabove grade, where it can beseen, until its temperature fallsagain below the limiting value.

CheckValve

CheckValve

SupervisedStart-up

Valve

Set downabout 2"

88

HOOK-UP DIAGRAMS

A. TD traps on high temperature tracingapplication where tracer line must bedrained clear of condensate.

B. TSS300 traps on low temperature tracingwhere product temperature is below 150˚Fand some of sensible heat in condensatemay be utilized to improve efficiency.

Figure II-10 Typical Steam Tracer Trapping Arrangements

Thermo-Dynamic

Steam Trapwith Integral

Strainer

BalancedPressure

ThermostaticSteam Trap

Spira-tecLoss

Detector

Spira-tecLoss

DetectorStrainer

TracerTracer

Product Line Product Line

Insulation

A B

Steam will automatically shut downas ambient temperatures rise aboveproduct solidification temperature.Select self acting temperature controlfor number of tracer lines.

Figure II-11Steam Tracing System withPreassembled Manifolds

AmbientSensing

TemperatureControl

Strainer

SteamMain

SteamDistribution

Manifold

CondensateCollectionManifold

Steam Trap Stationwith Test Valves

Steam Trap Stationwith Test Valves

Steam toTracers

Condensatefrom Tracers

To Drain

ToCondensate

Return

To drain during supervisedstartup or during shutdown

Steam is uniformly distributed to tracers by forged steel manifold with integral pis-ton valves. After supplying heat to tracer lines, condensate is collected infabricated manifold preassembled with steam trap stations. Three-way test valvesallow for startup purging, checking of lines for blockage, isolation of trap for main-tenance, and visual testing of steam trap operation. Condensate manifold has aninternal siphon pipe to reduce waterhammer and provide freeze protection.

89

HOOK-UP DIAGRAMS

Spira-tecLoss

Detector

StrainerSelect inlet piping for reasonablevelocity and expand downstreamfor equal flow rate.

Figure II-12Typical Pressure Reducing Valve Station

Float &ThermostaticSteam Trap

Strainer

SafetyValve

SteamSupply

Pilot OperatedPressure Control Valve

Figure II-13Parallel Operation of Pressure Reducing Valves

Set lead valve 2 psi above desiredset pressure and set lag valve 2 psibelow desired set pressure.

Spira-tecLoss

Detector

Strainer

SafetyValve

SteamSupply

Pilot OperatedPressure Control Valve

Pilot OperatedPressure Control Valve

Strainer

Strainer

Float &ThermostaticSteam Trap

MoistureSeparator

PressureSensing Line

PressureSensing Line

CheckValve

DripPan

Elbow

MoistureSeparator

ReducedSteam

Pressure

CheckValve

DripPan

Elbow

ReducedSteam

Pressure

90

HOOK-UP DIAGRAMS

Figure II-14Series Pressure Reducing Valve Station for High Turndown Rations

Note: Intermediate pressure takeoff requires an additional safety valve.

Spira-tecLoss

Detector

Strainer

SafetyValve

SteamSupply

Pilot OperatedPressure Control Valve

Pilot OperatedPressure Control Valve

Strainer Strainer

Float &ThermostaticSteam Trap

MoistureSeparator

PressureSensing

Line

Spira-tecLoss

Detector

Strainer

Float &ThermostaticSteam Trap

PressureSensing

Line

Figure II-15Hook-up for Remote Operation of 25 PRM Pressure Reducing Valve

Float &ThermostaticSteam Trap

Float &ThermostaticSteam Trap

Float &ThermostaticSteam Trap

Strainer

Strainer

SafetyValve

SteamSupply

MoistureSeparator

MainControl Valve

RemotePressure

Pilot

Limit pilot to 15 ft. drop below mainvalve and drain all supply tubing. Ifpilot is mounted above main valve,pilot line drip traps can be eliminated.For longer distance an air loadedpilot should be used.

CheckValve

DripPan

Elbow

ReducedSteam

Pressure

CheckValve

DripPan

Elbow

ReducedSteam

Pressure

CheckValve

CheckValve

CheckValve

Noise Diffuser(if required)

5/16" CopperTubing or 1/4" Pipe

1/2" Pipe

91

HOOK-UP DIAGRAMSFigure II-17

Low Capacity Pressure Reducing Station

Figure II-16Installation of Pressure Reducing Valve in “Tight Spaces”

PressureSensing LinePitch Down

Spira-tecLoss

Detector

Strainer

Thermo-DynamicSteam Trap

SafetyValve

Strainer

DirectOperatedPressureReducing

Valve

ReducedSteam

Pressure

10 PipeDiametersMinimum

Strainer

Strainer

Strainer

Float &ThermostaticSteam Trap

SteamSupply

MoistureSeparator

Float &ThermostaticSteam Trap

Float &ThermostaticSteam Trap

Strainer

SafetyValve

DripPan

Elbow

ReducedSteam

Pressure

CheckValve

CheckValve

CheckValve

Noise Diffuser(if required)

Pilot OperatedPressureControlValve

Ten PipeDiameters

DripPan

Elbow

92

HOOK-UP DIAGRAMS

Figure II-1825 BP Back Pressure Controls used to Restrict Supply to Low Priority Uses at Times of Overload

Steam toNon-essential

ServiceStrainer

Thermo-Dynamic

Steam Trapwith Integral

Steam Supplyfrom Boiler

Strainer

Pilot OperatedPressure Reducingand Back Pressure

Valve

Steam toPriority Use

10 Pipe DiametersMinimum fromValve Outlet

At times of peak draw off, boilers which have sufficientcapacity to meet average load conditions may become over-loaded. This can cause carryover and priming, or evenlockout of boilers on low water. The pressure in the steamlines falls and essential services may be interrupted. Theuse of back pressure controls in the supplies to non-essen-tial loads allows these to be automatically shut down, inorder of priority, at peak load times while maintaining supplyto more important loads.

Spira-tecLoss

Detector

Header

Pilot OperatedBack Pressure Valve

Figure II-19Reducing Steam Pressure Using 25PA Control Valve with Remote Air Valve

Depending on pilot selected, reducedsteam pressure will be approximately 1:1,4:1 or 6:1 times the air loading pressuresent to the pilot.

SafetyValve

Spira-tecLoss

Detector

Strainer

Strainer

Float &ThermostaticSteam Trap

Filter/Regulator

SteamSupply

MoistureSeparator

AirSupply

PressureSensing LinePitch Down

Air Loaded

Pilot

Air OperatedControl Valve

DripPan

Elbow

ReducedSteam

Pressure

CheckValve

DripPan

Elbow

SafetyValve

Reduced SteamPressure to

Non-essential Service

93

HOOK-UP DIAGRAMS

Figure II-20Typical Pneumatic Single StagePressure Reducing Valve Station

Figure II-22Hook-up for 25 TRM Temperature Control Remotely Mounted (within 15 ft. of Main Valve)

StrainerSteamSupply

MoistureSeparator Main

Control Valve

Float &ThermostaticSteam Trap

Strainer

Float &ThermostaticSteam Trap

RegulatedSteam toProcess

Sensor

1/2" Pipe

Figure II-21Pneumatic Temperature Control of Heat Exchanger

StrainerSteamSupply

MoistureSeparator

Float &ThermostaticSteam Trap

Strainer

SafetyValve

VacuumBreaker

Strainer

MoistureSeparator

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss

Detector

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss

Detector

SteamSupply

DripPan

Elbow

ReducedSteam

Pressure

Noise Diffuser(if required)

SupplyAir

ControlSignal

PneumaticControlValve

CheckValve

Controller

Controller PneumaticControl Valve

with Positioner

Supply Air

Control Signal

Supply Air

Heat Exchanger

CheckValve

CheckValve

Sensor

Liquid in/out

CheckValve

CheckValve

RemoteTemp.Pilot

5/16" Copper Tubingor 1/4" Pipe

94

HOOK-UP DIAGRAMS

Figure II-23Pressure Reducing Valve for Pressure Powered Pump Motive Steam

Figure II-24Heat-up, Pressuring and Shutdown of Steam Mainsusing On/Off Control Valves and Programmer

Thermo-Dynamic

Steam Trapwith Integral

Pilot OperatedOn/Off Control Valve

(for heatup only)

Spira-tecLoss

Detector

Strainer

SteamSupply

Strainer

Thermo-Dynamic

Steam Trapwith Integral

Spira-tecLoss

Detector

Pilot OperatedOn/Off Control Valve(for maximum flow)

SteamMain

AutomaticTime

Switch

Power

Thermo-Dynamic

Steam Trap

SteamSupply

Strainer

Strainer

SafetyValve

DripPan

Elbow

MotiveSteam

to Pump

Direct or Pilot OperatedPressure Reducing Valve

Pressure Surge Reservoir1-1/2" or 2" diameter, 6’ longwith eccentric fittings on ends

Steam toSystem

Hand Valveto adjustflow rate

AdjustablePressurestat

(with N.O. Switch)

95

HOOK-UP DIAGRAMS

Figure II-25Complete CondensateDrainage from Air HeaterCoil under “Stall” withCombination Pump/Trapin a Closed Loop System

When the steam pressure within thecoil is high enough to push conden-sate through the steam trap, againstany back pressure from a lift to high-er level or into a pressurized line, thepump is inoperative. If the action ofthe temperature control lowers thecoil pressure sufficiently, the conden-sate flow stalls. Water backing up intothe PPP body brings it into operationand the pump uses motive steam topush the condensate through the trapto the return line.At the end of each discharge stroke,the motive steam in the pump body isexhausted through a balance line tothe top of the liquid reservoir. A ther-mostatic air vent on the balance linevents air under startup conditions,even if the pump/trap is fully floodedwith condensate at this time.

Figure II-25AProcess Condensate Removal Module

A preassembled modular pumping systemprovides a sole source solution for airheater coil applications.

Float &ThermostaticSteam Trap

Direct orPilot OperatedTemperature

Control

Strainer

SteamSupply

MotiveSteamSupply

PressurePowered

Pump

MoistureSeparator

Thermo-Dynamic

Steam Trap

Reservoir

CondensateReturn

HeatedAir

Outlet

TemperatureControlSensor

Thermostatic

AirInlet

CheckValve

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss Detector

Strainer

Coil

Drain toSafePlace

See Fig. II-25A for thepreassembled

Process CondensateRemoval Module

Steam Trap Station

96

HOOK-UP DIAGRAMS

Figure II-26Controlling and Draining Preheat andReheat Coils in Vented CondensateSystem with Freeze Resistant Pipingfor Makeup Air

Each coil must be individually drainedto provide for proper and accuratecontrol. Strainers are not fitted in frontof the traps in case they become par-tially blocked. Freeze resistant coilsmust have vacuum breaker, trapssized for full load with 1/2 psi differen-tial and unobstructed piping to anatmospheric return system.

Float &ThermostaticSteam Trap

Pilot OperatedTemperatureControl Valve

Spira-tecLoss

DetectorMotiveSupply

PressurePowered

Pump

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Vented Receiver CondensateReturn

TemperatureControlSensor

Thermostatic

Pilot OperatedTemperatureControl Valve

Thermostatic

Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

Strainer

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss

Detector

TemperatureControlSensorHeated

AirOutdoor

Air

VacuumBreaker

SteamSupply

SteamSupply

Thermo-Dynamic

Steam Trapwith Integral

Strainer

VacuumBreaker

LiquidExpansionSteam Trap

LiquidExpansionSteam Trap

Drain toSafePlaceDrain to

SafePlace

97

HOOK-UP DIAGRAMS

Figure II-27Freeze Proof Piping ofLarge Vertical Air Heater Coil toAtmospheric Condensate Return System

* To preclude accidental closing, these valvesshould be chain locked in open position, orthey may be omitted.

Figure II-28High Pressure SteamCoils Trapped forFlash Recovery to LPSteam System

Float &ThermostaticSteam Trap

Pilot OperatedTemperatureControl Valve

MotiveSupply

PressurePowered

Pump

Thermo-Dynamic

Steam Trapwith Integral

Strainer

CondensateReturn

TemperatureSensor

Thermostatic

Float &ThermostaticSteam Trap

Strainer

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss

Detector

Thermo-Dynamic

Steam Trap

PackagedPressurePowered

Pump Unit

Strainer

Spira-tecLoss

Detector

VerticalAir Coil

SteamSupply

Pilot OperatedBack PressureControl Valve

Condensate ReturnPitch Down

MoistureSeparator

Float &ThermostaticSteam Trap

Strainer

FlashRecovery

Vessel

Float &ThermostaticSteam Trap

Strainer

Pilot OperatedPressure

Control Valve

SafetyValve

SafetyValve

VacuumBreaker

VacuumBreaker

**

Vent

SteamSupply

Vent

DripPan

Elbow

CheckValve

To CondensateReturn

DripPan

Elbow

AirVent

AirHeating

Coils

Low Pressure Steam

Drain toSafePlace

98

HOOK-UP DIAGRAMS

Figure II-29Storage Cylinder withHigh Limit Protection

Fail safe protection against excess temperatures is provided by a separate con-trol valve, normally latched wide open. If the 130 self-acting control systemdetects a temperature overrun, or if the control system itself is damaged, a pow-erful spring is released in the HL10 unit and the high limit valve is driven closed.A switch is available as an extra to provide electrical warning that the device hasbeen actuated.

Figure II-30Condensate Drainage from Unit Heater

TemperatureControlSensor

Spira-tecLoss

Detector

Valve

MoistureSeparator

Float &ThermostaticSteam Trap

Float &ThermostaticSteam Trap

Strainer

Self ActingTemperature

Control

Spira-tecLoss

Detector

Strainer

SteamSupply

Strainer

High Limit130 Sensor

HL10OverheatProtection

Hot Flow

Circ.Return

ColdSupply

StorageTank

Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

Strainer

SteamSupply

UnitHeater

Drain condensateby gravity where

possible—especially to vac.

return system

VacuumBreaker

CheckValve

CheckValve

ToCondensate

Return

ToOverhead

Return

Liquid ExpansionSteam Trap

To Drain

AlternateLocation

Note: The Liquid ExpansionSteam Trap will automaticallydrain unit heater during peri-ods of shutdown which willprevent damage due to cor-rosion.

Liquid ExpansionSteam Trap

99

HOOK-UP DIAGRAMS

Figure II-31Temperature Control of Warm-up and RunningLoads at Storage Tank

Figure II-32Draining Heat Exchanger under Constant “Stall”Condition with Pumping Trap in Closed Loop System

A control valve suitably sized to supply the start upload on a tank is often very much oversized for therunning load, and this oversizing can lead to erraticcontrol. In such cases, a large control valve may beused to meet the warm up load, arranged to closeat a temperature perhaps 2° below the final controltemperature. The smaller control valve meets therunning load, and the supply is supplementedthrough the start up valve, only when the capacity ofthe smaller valve is exceeded.

Draining L.P. Heat Exchanger toOverhead Return. Pressure at pumpoutlet P2 always exceeds supplypressure P1 to Heat Exchanger.Completely immerse control sensorwithout well, right at hot outflow.To prevent overheating, the sensormust not see a “dead” flow.

LowTemperature

Sensor

Spira-tecLoss

Detector

MoistureSeparator

ThermostaticSteam Trap Strainer

RunningTemperature

ControlValve

StrainerSteamSupply

CondensateReturn

StorageTank

Spira-tecLoss

Detector

StrainerFloat &ThermostaticSteam Trap

Warm UpTemperature

ControlValve

RunTemperature

Sensor

Thermo-static

Air Vent

MoistureSeparator

Pilot OperatedTemperatureControl Valve

Strainer

SteamSupply

Heat Exchanger

Spira-tecLoss

Detector

Strainer

PressurePowered

Pump

Thermo-DynamicSteamTrap

Float &ThermostaticSteam Trap

Hot

Cold

MotiveSteamSupply

Reservoir

Sensor

PressurizedReturnSystem

CheckValve

Strainer

Check Valve

P1

P2

Drain toSafePlace

100

HOOK-UP DIAGRAMS

Figure II-33Combined Pressureand TemperatureControl of HeatExchanger

When the pressure of the steam supply is higher than theheat exchanger can withstand, or is at a higher valuethan necessary to allow for fouling of the heat exchangesurfaces, a pressure reducing valve is required. This caneconomically be combined with a temperature control byusing pressure sensing and temperature sensing pilotsto operate a common main valve. Sensor bulb must befully immersed right at hot outflow and use of a separa-ble well should be avoided.

Figure II-34Draining Small Heat Exchanger andOther Loads to Pressure Powered Pump

Arrangement of Small Steam/Liquid HeatExchanger where steam space pressure may fallbelow back pressure and trap has gravity drain.Note: Head “H” must be enough to give trapcapacity needed when steam space pressurefalls to zero.

ThermostaticAir Vent

MoistureSeparator

Pilot OperatedPressure/Temperature

Control Valve

Heat Exchanger

Spira-tecLoss

Detector

StrainerFloat &

ThermostaticSteam Trap

ColdWaterSupply

Sensor

Spira-tecLoss

Detector

Float &ThermostaticSteam Trap

SafetyValve

Strainer

GravityReturn

SteamSupply

StrainerFloat &

ThermostaticSteam Trap

SteamSupply

Spira-tecLoss Detector

StrainerFloat &

ThermostaticSteam Trap

VacuumBreaker

Temp.ControlSensor

Self ActingTemperature

ControlMoistureSeparator

Heat Exchanger

PressurePowered

Pump

ReceiverStrainer

Thermo-Dynamic

Steam Trap

CondensateReturn

Multiple LoadsConnected to

Vented Receiver

Spira-tecLoss Detector

VacuumBreaker

Drip PanElbow

LiquidIn/OutFlow

Strainer

H

See Fig. II-34A forthe preassembled

CondensateRecovery Module

Drain toSafePlace

Steam Trap Station

Steam Trap Station

Note: scensor mustnot see a“dead” flow.

Note: scensor mustnot see a“dead” flow.

101

HOOK-UP DIAGRAMS

Figure II-35Draining Equipment to PressurizedReturn with Closed LoopPump/Trap Drainage System

P1 exceeds P2 except when partialloads “stall” the exchanger. With thishook up, the reservoir pipe is alwaysconnected to, and at the same pres-sure as, the heat exchanger steamspace. Condensate drains to it freely.The pump body is connected in thesame way, except during the dischargestroke when the inlet check valve andthe exhaust valve are closed. After dis-charge, the residual steam in the pumpbody is exhausted to the heater and itslatent heat can then be recovered.Steam trap functions at full load andThermoton drains at shutdown.

SteamSupply

Spira-tecLoss Detector

Strainer

Float &ThermostaticSteam Trap

PneumaticControlValve

MoistureSeparator

Heat Exchanger

PressurePowered

Pump

Reservoir Pipe

Drain

Thermo-Dynamic

Steam Trap

Elevated orPressurizedReturn

Strainer

Strainer

Spira-tecLoss Detector

Float &ThermostaticSteam Trap

HotFlow

CoolReturn

MotiveSteam Supply

Thermo-static

Air Vent

P1

P2

See Fig. II-35A forthe preassembled

Process CondensateRemoval Module

Figure II-35AProcess Condensate Removal ModuleA preassembled modular will remove condensate from the heat exchanger under all operating conditions.

Figure II-34ACondensate Recovery ModuleA preassembled modular pumping system can be usedto recover and reuse the condensate.

Sensor

Controller

SupplyAir

ControlSignal

Drain toSafePlace

Steam Trap Station

Liquid ExpansionSteam Trap

Note: To prevent overheating, the scensor must not seea “dead” flow.

102

HOOK-UP DIAGRAMS

Figure II-36Low Pressure Steam Absorption Chiller

Figure II-37High Pressure Steam Absorption Chiller

Float &ThermostaticSteam Trap

PressurePowered

Pump

Reservoir Pipe

Thermo-Dynamic

Steam Trapwith Integral

Strainer

ToCondensate

Return

MotiveSteam Supply

ThermostaticAir Vent

CheckValve

AbsorptionChiller

Steam Supply(15 psig or less)

ToCondensate

Return

MotiveSteam Supply

Absorption Chiller

Steam Supply(normally 45

psig or higher)

Vent

PackagedPressurePowered

Pump

Thermo-DynamicSteam Trapwith Integral

Strainer

Note: Depending on chiller manufacturer, a steam trapmay not be required or it may be supplied with the chiller.Other specialties needed may include a steam pressurereducing valve on the inlet, steam separator with trap,steam safety valve or inlet strainer.

Drain toSafe Place

103

HOOK-UP DIAGRAMS

Figure II-38 Automatic Control of BatchProcessor with Electrical Time SequenceProgrammer

Figure II-39Controlling Temperature of Open Tankfor Plating, Dyeing of Process Work

ThermostaticAir Vent

SteamSupply

Spira-tecLoss Detector

Float &ThermostaticSteam Trap

Pilot OperatedPressure/Temperature

Control Valvewith Solenoid

MoistureSeparator

Autoclave

SafetyValve

Strainer

Strainer

Spira-tecLoss

Detector

Float &ThermostaticSteam Trap

ElectricOperator

Spira-tecLoss

Detector

Strainer

Float & ThermostaticSteam Trap

SteamFilter

Power

StrainerFloat &

ThermostaticSteam Trap

Spira-tecLoss

DetectorStrainer

Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

MoistureSeparator

Strainer

PressureSensing LinePitch Down

Strainer

PilotOperated

TemperatureControl Valve

LoopSeal

GravityReturn

DripPan

Elbow

BalancedPressure

ThermostaticSteam Trap

SteamSupply

Drain toSafe Place

SmallBoreRiser

104

HOOK-UP DIAGRAMS

Figure II-40Controlling Platen Press Temperaturewith Pressure Regulator and ElectricProgrammer. Indicating Pilot PermitsFast Temperature Changes

Figure II-41Controlling Temperature of Pressurized Boiler Feed Water Tank

Note: When supply pressure is above 125 psi, install an additionalSpirax Sarco pressure control valve ahead of pressure/temperaturecontrol valve to reduce pressure to 125 psi.

Strainer

Thermo-DynamicSteam Traps withIntegral Strainer

Spira-tecLoss Detector

Strainer

Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

Strainer

Pressure ReducingControl Valvewith Solenoid

SteamSupply

MoistureSeparator

SafetyValve

ElectricOperatorPower

PressureSensing LinePitch Down

Float &ThermostaticSteam Trap

Condensate Return

Strainer

Spira-tecLoss

Detector

Strainer

Pilot OperatedPressure/Temperature

Control Valve

SteamSupply(125 psior less)

MoistureSeparator

SafetyValve

Float &ThermostaticSteam Trap

VacuumBreaker

Pilot OperatedBack PressureControl Valve

PerforatedHeater Tube

Pack HeatCompoundin Bulb Well

Make upWaterSupply

PumpSuction

CondensateReturn

ThermostaticAir Vent

DripPan

Elbow

Drain toSafe Place

105

HOOK-UP DIAGRAMS

Figure II-42Controlling Temperature of Vented Boiler Feed Water Tank

Figure II-43Controlling Temperature of Large Open Tank Heated by Direct Steam Injection

Strainer

Spira-tecLoss

Detector

Strainer

Pilot OperatedTemperatureControl Valve

MoistureSeparator

Float &ThermostaticSteam Trap

VacuumBreaker

SteamInjector

SteamSupply

OpenTank

Provide suitable supportand protection for

capillary tubing andtemperature bulbs

VacuumBreaker

Strainer

CondensateReturn

VentHead

SteamSupply

TemperatureControl Valve

Sensor

To B.F. PumpSuction

Perforated Heater Tube

Make upWater

CondensateReturn

106

HOOK-UP DIAGRAMS

Figure II-44Controlling Temperature of Small Open Tank, Heated by Direct Steam Injection

Figure II-45Controlling Temperature of Water Suppliedto Spray Nozzles of Egg Washing Machine

Strainer

SteamInjector/

Thermoton

VacuumBreaker

Strainer

Spira-tecLoss

Detector

Strainer

Pilot OperatedTemperatureControl Valve

SteamSupply

MoistureSeparator

ColdWaterSupply

Float &ThermostaticSteam Trap

VacuumBreaker

Pack Sensor Well withHeat Conducting

CompoundSteam Injector

CentrifugalPump

Float OperatedC.W. Valve

WarmWaterSupply

to WasherSpray

Nozzles

GravityReturnfrom

Washer

Open Tank

Vent

107

HOOK-UP DIAGRAMS

Figure II-46Controlling Temperature of Greenhouse or Other Similar Buildings

Figure II-47Steam Radiator

Strainer

Spira-tecLoss

DetectorStrainer

Fin-TubeRadiation

SteamSupply

MoistureSeparator

Float &ThermostaticSteam Trap

RoomThermostat

LiquidExpansionSteam Trap

Pilot OperatedOn/Off Control Valve

Return

ThermostaticRadiator Trap

RadiatorValve

Supply

108

HOOK-UP DIAGRAMS

Figure II-48Trapping and Air Venting HospitalSterilizer with Dry Steam Supply

Figure II-49Control and Drainage Hook-up forHospital Blanket and Bedpan Warmer

Strainer

Spira-tecLoss

Detector

Strainer

SteamSupply

MoistureSeparator

Float &ThermostaticSteam Trap

ThermostaticAir Vent

Float &ThermostaticSteam Trap

Float &ThermostaticSteam Trap

ThermostaticAir Vent

Ball Valve

Thermo-Dynamic

Steam Trap

Filter

Spira-tecLoss

Detector

Strainer

Float &ThermostaticSteam Trap

Thermo-Dynamic

Steam Trapwith Integral

Strainer

MoistureSeparator

BalancedPressure

ThermostaticSteam Trap

Spira-tecLoss

Detector

Self ActingTemperature

Control

HeatingCoil

Small size trapis required

Drain toSafe Place

SteamSupply

109

HOOK-UP DIAGRAMS

Figure II-50Trapping Small Utensil Sterilizer

Figure II-51Condensate Drainage fromHospital Mattress Disinfector

Strainer

SteamSupply

Balanced PressureThermostaticSteam Trap

Strainer

SteamSupply

Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

Spira-tecLoss

Detector

Strainer Float &ThermostaticSteam Trap

ThermostaticAir Vent

Strainer

Drain toSafe Place

110

HOOK-UP DIAGRAMS

Figure II-52Float & Thermostatic TrapFreeze Resistant Hook-up

Float &ThermostaticSteam Trap

Liquid ExpansionSteam Trap

VacuumBreaker

Figure II-53Thermoton Controlling Temperatureof Large Storage Tank

LiquidExpansionSteam Trap

SteamSupply

Strainer

Strainer

Figure II-54Equipment Drained with Permanent Connector Thermo-Dynamic Steam Trapsthat fit into both Horizontal and Vertical Pipework

Floor

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Thermo-Dynamic

Steam Trapwith Integral

StrainerThermo-Dynamic

Steam Trapwith Integral

Strainer

CondensateReturn

Steam Main

StorageTank

111

HOOK-UP DIAGRAMS

Figure II-55Draining and Air VentingFlatwork Ironer

The steam traps are often located atone end for ease of maintenance,with long pipes connecting them tothe drainage points. If steam-lockingis a problem in these long pipes,then a Float / Thermostatic steamtrap with a steam-lock release is thebest selection. The beds should beair vented at points remote from thesteam entry. Steam supply lines toironers should be drained, ideallyusing a separator.

Figure II-56System Units for Condensate Removaland Air Venting of Rotating Cylinders(for surface speeds below 800 FPM)

GravityReturn

StrainerSightGlass with

Check Valve

Steam Beds

BalancedPressure

ThermostaticAir Vent

Strainer

BalancedPressure

ThermostaticAir Vent

Float &ThermostaticSteam Trapwith SLRfeature

SightGlass

GravityCondensate

Return

AirReservoir

Steam Main

RotatingCylinder

Drain toSafe Place

Float &ThermostaticSteam Trap

Drain toSafe Place

The Spirax Sarco units (Strainers,Float & Thermostatic Steam Traps withSLR feature, Sight Glass, Air Reservoirwith Air Vent) provides for the bestdrainage of condensate and non-condensibles from rotating cylinders.

112

HOOK-UP DIAGRAMS

Figure II-57 Draining High Speed Paper Machine using Cascading or “Blow-through” Systems

Paper Machines running at higherspeeds in modern plants usually havea cascading or “blow-through” sys-tem. Condensate is swept by the flowof blowthrough steam, up the dryercan dip pipe and into a manifold lead-ing to a blowthrough separator.Control of the blowthrough steam maybe at the separator outlet or on indi-

vidual cylinders or banks of cylinders.The blow-through steam may pass onto sections of the machine operatingat lower pressures. The blowthroughseparator is drained by an FT trap,unless the return is pressurized inwhich case a closed loop combinationpressure powered pump/trap isrequired.

Figure II-58 Draining High Speed Paper Machine using “Thermal-compressor” or Reused Steam Systems

Thermo-DynamicSteam Trapwith Integral

Strainer

Spira-tecLoss Detector

Float &ThermostaticSteam Trap

Thermo-DynamicSteam Trapwith Integral

Strainer

Spira-tecLoss Detector

Safety Valvewith Drip

Pan Elbow

Float &ThermostaticSteam Trap

Safety Valvewith Drip

Pan Elbow

Separator

Blow throughSeparator

CondensateReturn

CondensateReturn

DryerCans

CheckValve

CheckValve

L.P. SteamH.P. Steam

Thermal Compressor

L.P.Steam

By-Pass

Modern paper machines also use “Thermal-compre-sor” systems. Condensate is swept by the flow ofblow-through steam up the dryer can dip pipe andinto a manifold leading to a separator.The L.P. steamfrom the separator is then reused through an H.P.steam driven thermal compressor or by-passed. Theseparator is drained like Fig. II-57 or engineered sys-tems package, Fig. II-58A.

Figure II-58A Condensate Removal ModuleHigh speed paper machines can be fitted witha preassembled module that incorporates theseparator and condensate removal equipment.

DryerCans

SteamTrap

Station

See Fig. II-58A forthe preassembled

CondensateRemoval Module

113

HOOK-UP DIAGRAMS

Figure II-59Air Venting and Condensate Drainage at Jacketed Kettle

Figure II-60Draining Tire Mold

Figure II-61Steam Trapping High Pressure Coil (up to 600 psig)

Float &ThermostaticSteam Trap

Strainer

BalancedPressure

ThermostaticAir VentSteam

Supply

Thermo-Dynamic

Steam Trapwith Integral

Strainer

Spira-tecLoss

Detector

Spira-tecLoss

Detector

CondensateReturn

Float &ThermostaticSteam Trap

Strainer

BalancedPressure

ThermostaticAir Vent

Strainer

HPHeating

Coil

Condensate Return

Air

SteamSupply

(Air supply temp. not lower than 32°F)

Strainer

Thermo-Dynamic

Steam Trap

SteamSupply

FlexibleQuick

DisconnectLines

Drain toSafePlace

Drain toSafePlace

114

HOOK-UP DIAGRAMS

Figure II-62Draining High Pressure Reboiler

Figure II-63Draining Condensate to Vented Receiver andLifting Condensate to Overhead Return Main

Reboiler

Float &ThermostaticSteam Trap

Strainer

BalancedPressure

ThermostaticAir Vent

Strainer

Condensate Return

SteamSupply

Total back pressure is the height (H)in feet x .0433 plus PSIG in returnline, plus downstream piping frictionpressure drop in PSI (Determined bythe maximum instantaneous dis-charge rate of the selected pump.)

Drain toSafePlace

Thermo-Dynamic

Steam Trap

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss Detector

Thermo-Dynamic

Steam Trap

VentedReceiver

Return LinePressure Gauge

CondensateReturn Main

MotiveSupply

Strainer

SteamSpace

PressurePowered

Pump

Vent toAtmosphere

FillingHead

TotalLift“H”

115

HOOK-UP DIAGRAMS

Figure II-64Draining Evaporator whenEvaporator Steam Pressurecan fall from Above to BelowBack Pressure

Figure II-65Draining Condensate from vacuum Space to Return Main or Atmosphere Drain

Evaporator

ReservoirStrainer

ReturnMain

BalancedPressure

ThermostaticAir Vent

Thermo-Dynamic

Steam Trap

PressurePowered

Pump

1" Equalizer Line

Float &ThermostaticSteam Trap

MotiveSteamSupply

VacuumSpace

Reservoir

Strainer

ReturnMain

Thermo-Dynamic

Steam TrapPressurePowered

Pump

SteamSupply

Pipe toDrain

Pipe toDrain30"

WaterColumn

TotalLift“H”

FillingHead

1" Equalizer Line

ElevatedDischarge

Connection

1/8"Antisyphon

Hole

Drain toSafePlace

Check Valve

BackPressure

EvaporatorPressure

Drain toAtmosphere

116

HOOK-UP DIAGRAMS

Figure II-66Lifting Fluids from Low Pressure Sourceto Higher Pressure Receiver

Figure II-67Draining Equipment with Condensate Outlet Near Floor Level using a Pump/Trap Combination in a Pit

Reservoir

Strainer

BalancedPressure

ThermostaticAir Vent

SteamSupply

Low PressureSpace

Thermo-Dynamic

Steam TrapPressurePowered

Pump

PressurizedReceiver

Tank

Reservoir Pipe

Strainer

BalancedPressure

ThermostaticAir Vent

Motive Gas orSteam Supply

Thermo-Dynamic

Steam TrapPressurePowered

Pump

Float &ThermostaticSteam Trap

Equalizer Line

1" Equalizer Line

Total back pressureis the height (H) infeet x 0.433 plusPSIG in receiver, plusdownstream pipingfriction pressure dropin PSI (Determinedby the maximuminstantaneous dis-charge rate of theselected pump.)

Drain toSafePlace

Drain toSafe Place

Check Valve

CheckValve

TotalLift“H”

CheckValve

Check Valve

Check Valve

Drain toSafePlace

ToPressurized

Storage Tank

Plug

Condensatefrom

Equipment

117

HOOK-UP DIAGRAMS

When multiple pumps in parallelare used to meet the load, Pump#1 fills first and Pump #2 operatesat full load. Supply piping isarranged to reduce simultaneousdischarge. Better staging occurswhen Pump #2 is elevated 3” to 6”above the floor.Intake pipe to Pump #3 is locatedabove the Filling Head requiredby Pump #1 & #2 so it will functionas a “Standby” and only operateon peak loads or in the event ofprimary pump failure.

Figure II-68Installation of Pump/Trap Combinationwhen Vertical Space is Limited

Figure II-69Multiple Pressure Powered Pump Hookupsfor Staged Operation and Standby Duty

PressurePoweredPump #3

PressurePoweredPump #1

PressurePoweredPump #2

Receiver

Condensate

Supplies

Vent

Return

Return

Exhaust

PPF-Top

PressurePowered

Pump

Reservoir

Strainer

BalancedPressure

ThermostaticAir Vent

Thermo-Dynamic

Steam Trap

ReturnMain

Float &ThermostaticSteam Trap

Drain toSafePlace

Check Valve

Check Valve

MotiveSupply

Drain toSafePlace

CheckValve

Condensatefrom Process

Equipment

118

HOOK-UP DIAGRAMS

Figure II-70Pressure Powered Pump Draining Water from Sump Pit

Figure II-71Pressure Powered Pump Discharging to Long Delivery Line(Air Eliminator needed above return main wherever

elevation changes form a water seal.)

Total back pressure is theheight (H) in feet x .0433 plusPSIG in return line, plusdownstream piping frictionpressure drop in PSI(Determined by the maximuminstantaneous discharge rateof the selected pump.)

ReturnMain

PressurePowered

Pump

Receiver

PressurePowered

Pump

Condensate

VacuumBreaker

Float OperatedAir Vent

ReceiverWaterSeal

Strainer

Thermo-Dynamic

Steam Trap

Pump ExhaustPiped to Safe Place

MotiveSupply

Drain

OperatingWaterLevel

15°SwingCheck

Figure II-72Pressure Powered Pump Discharging toLong Delivery Line with Lift at Remote End

See Fig. II-72 forhook-up option withLift at Remote End

Receiver

ReturnMain

Line SizeCheck Valve

Height“H”

Covering Grate

Line SizeCheck Valve

Line SizeCheck Valve

Line SizeCheckValve

Strainer

MotiveSupply

119

HOOK-UP DIAGRAMS

Figure II-73Draining Small Condensate Loads fromVacuum using Atmospheric Pressure

Figure II-74Typical Electric Pump Hook-upfor Subcooled Condensate

Figure II-75Electric Pump Lifting Condensatefrom Vented Receiver to HigherPressure or Elevation

Vent toAtmosphere

PumpDischarge

Condensate fromLow Pressure

System

Floor

PressurePowered

Pump

Inlet Open toAtmosphere

Check valve should be vacuumtight and water sealed. Largerdrop reduces emptying time.

Sub Atmospheric Line

EqualizerLine

To Drain

SwingCheckValve

MinimumDrop 3"

Receiver

ElectricCondensate

Pump

ElectricCondensate

Pump

Strainer

PumpDischarge

Vent

H. P.Condensate

Drain

Gate &Check Valves

VentHead

120

HOOK-UP DIAGRAMS

Figure II-76Typical Flash SteamRecovery Hook-up

Figure II-77Flash Steam Recovery with Live Steam Make upand Back Pressure Surplussing Valves

Condensate from high pressure loads releases steam by flash-ing as it passes to the lower pressures, downstream of the highpressure traps. The mixture of steam and condensate is readi-ly separated in Flash Vessels of appropriate dimensions andproportions. A supply of Low Pressure steam then becomesavailable for use on any application which can accept steam atthis low pressure, or the separated steam may simply be takeninto the LP steam mains, where it is supplemented throughpressure reducing valves, for general plant use.Where the supply of flash steam may at times exceed thedemand from the LP system, the surplus flash steam can bedischarged through a back pressure control valve. This is setat a few psi above the normal LP steam pressure, but belowthe setting of the LP safety valve. See Figure II-77.The condensate leaving the flash recovery vessel is at low pres-sure. Usually it is handled by a float-thermostatic steam trap andis delivered to the receiver of a condensate pump for return tothe boiler house. Any residual flash steam from the low pressurecondensate is vented from the pump receiver. (Figure II-78.)In some cases, pressures are sufficiently high that the flashcan be taken off at an intermediate pressure and the con-densate leaving the flash vessel still contains a usefulamount of sensible heat. It can then be taken to a secondflash vessel working at low pressure, so that the maximumheat recovery is effected. The use of two flash vessels inseries, or “cascade”, means that these vessels may beinstalled generally as Figure II-76 and II-77.Alternatively, it may be desirable to use the recovered flashsteam at a low pressure, below that in the condensate returnline or perhaps the de-aerator tank. The arrangement adapt-ed may then be either as Figure II-78 or as Figure II-79. Thislatter system uses a steam powered pump, with the bottomof the flash recovery vessel serving as the pump receiver.Power steam used by the pump is vented to the LP steamline, so that pumping is achieved at virtually zero cost and theuse of unsightly or wasteful vents is avoided.

Strainer

ThermostaticAir Vent

Float &ThermostaticSteam Trap

Strainer

ThermostaticAir Vent

Strainer Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

SafetyValve

Spira-tecLoss

Detector

Strainer

Float &ThermostaticSteam Trap

Spira-tecLoss Detector

SafetyValve

Strainer

FlashRecovery

Vessel

FlashRecovery

Vessel

MoistureSeparator

Pilot OperatedPressure

Control Valve

H. P. Condensate

H. P.SteamSupply

L. P.Steam

Pilot OperatedBack PressureControl Valve

Vent

L. P.Condensate

H. P. Condensate

L. P. Steam Main

L. P.Condensate

DripPan Elbow

DripPan

ElbowH. P. Condensate

CheckValve

Drain toSafe Place

Drain toSafePlace

121

HOOK-UP DIAGRAMS

Figure II-78Flash Steam Recovery at Pressure above Atmospheric with L.P.Condensate Returned by Packaged Pressure Powered Pump Unit

Figure II-78ACondensate Recovery Module

A preassembled modular pumpingsystem provides a sole sourcesolution for condensate recoveryapplications.

Strainer

Float &ThermostaticSteam Trap

Spira-tecLoss

Detector

SafetyValve

FlashRecovery

Vessel

MoistureSeparator

Strainer Float &ThermostaticSteam Trap

Spira-tec LossDetector

Strainer

Strainer

H. P. Condensate

Pilot OperatedBack PressureControl Valve

Pilot OperatedPressure

Control Valve

PressurePowered

Pump

Strainer

Vent

DripPan

Elbow

L.P.Condensate

Inlet

Thermo-Dynamic

Steam Trap

PackagedPressurePowered

Pump

CheckValve

High PressureMakeup Supply

Low PressureSteam System

CondensateReturn

Strainer

Vent toAtmosphere

Steam Trap Station

Steam Trap Station

See Fig. II-78A forthe preassembled

CondensateRecovery Module

122

HOOK-UP DIAGRAMS

Figure II-79Flash Steam Recovery at Pressure Above or Below Atmosphericin ASME Coded Receiver of Packaged Pump Unit

Figure II-79ACondensate and Flash SteamRecovery Module

A preassembled modular pumpingsystem will recover condensate anddirect flash steam to a low pressure user.

Strainer

Float &ThermostaticSteam Trap

SafetyValve

MoistureSeparator

Strainer

Float & ThermostaticSteam Trap

Strainer

Strainer

H. P.MakeupSupply

ToCondensate

ReturnMain

Motive SteamSupply

Vent toAtmosphere

Pilot OperatedPressure ReducingValve (for makeup)

PressurePowered

Pump

Pilot OperatedBack PressureControl Valve

H. P.Condensate(from traps)

DripPan

Elbow

L. P.MakeupSupply

Overflowto

Drain

Packaged ASMECode Stamped

Pressure PoweredPump Unit

Steam Trap Station

See Fig. II-79A for the preassembledCondensate and Flash Steam

Recovery Module

123

HOOK-UP DIAGRAMS

Figure II-80Heating Water using Recovered Flash Steam with PackagedPump Unit Also Handling Other Condensate

Strainer

SafetyValve

FlashRecovery

Vessel

ThermostaticAir Vent

Strainer

Float & ThermostaticSteam Trap

Thermo-Dynamic

Steam Trap

Strainer

Heated Water

MotiveSteamor Gas

Vent toAtmosphere

Heat Exchanger

PressurePowered

Pump

CondensateReturn

Float & ThermostaticSteam Trap

VacuumBreaker

Cold Water Inlet

H.P.Condensate

& Flash

PumpExhaust

Pilot OperatedBack PressureControl Valve

Condensate from high pressure steam sources iscollected in a flash steam recovery vessel. Flashsteam is separated from the condensate which drainsthrough an F & T trap set to the vented receiver of acondensate pump.The flash steam is condensed in aheat exchanger, giving up its heat content to thewater which is to be heated (or preheated).Condensate from the exchanger also drains throughan F & T trap set to the pump receiver. Non-conden-sibles are discharged at the receiver vent.

DripPan

Elbow

Pipe toSafe Place

Steam Trap Station

Steam Trap Station

See Fig. II-80Afor the

preassembledCondensate

RecoveryModule

Figure II-80ACondensate Recovery ModuleA preassembled modular pumping system can be usedto recover and reuse the condensate.

124

HOOK-UP DIAGRAMS

Figure II-81Heating Water using Flash Steam Recovered in ASME CodedReceiver of Packaged Pressure Powered Pump Unit

Strainer

SafetyValve

ThermostaticAir Vent

Thermo-DynamicSteamTrap

StrainerHeated Water

Vent toAtmosphere

Heat Exchanger

PressurePowered

Pump

CondensateReturn

Cold Water Inlet

H.P.Condensate

& Flash

PumpExhaust

Pilot OperatedBack PressureControl Valve

DripPan

ElbowPipe to

Safe Place

PackagedASME CodeStamped Unit

125

HOOK-UP DIAGRAMS

Figure II-82Recovery of Flash Steam and Pump Power Steam on Preheater (Steam in the Shell)

Condensate from the main heatexchanger flows to a flash SteamRecovery Vessel. The flash steam isseparated and led to the Preheaterwhere it is condensed as it preheatsthe incoming cool water or other liq-uid. Any incondensibles aredischarged to atmosphere throughthe thermostatic air vent.

Residual condensate from the flashvessel, with that from the preheater,falls to the inlet of the PressurePowered Pump. Pump exhaust steamis taken to the Flash Steam line andits heat content recovered in the pre-heater.

A Packaged Pump Unit with ASMEcoded receiver can be used in placeof the component flash vessels andPressure Powered Pump.

SafetyValve

FlashRecovery

Vessel

Strainer

Float &ThermostaticSteam Trap

Strainer

Heat Exchanger

PressurePowered

Pump

ToCondensate

Return

VacuumBreaker

CoolReturn

SteamSupply

PilotOperated

BackPressure

Valve

Float &ThermostaticSteam Trap

Pre-Heater

AirVent

ToVent

MoistureSeparator

Strainer

TemperatureControlValve

ToVent

AirVent

Strainer

Thermo-DynamicSteam Trap

Sensor

HeatedOutlet

Pipe toSafePlace

CheckValve

Pipe toSafePlace

Motive Steam Supply

DripPan

Elbow

CheckValve

CheckValve

126

HOOK-UP DIAGRAMS

Figure II-83Recovery of Flash Steam and Pump Power Steam in Preheater (Steam in Tubes)

Safety Valvewith Drip

Pan Elbow

FlashRecovery

Vessel

Strainer

Float &ThermostaticSteam Trap

Strainer

HeatExchanger

PressurePowered

Pump

CondensateReturn

VacuumBreaker

BackPressureControlValve

Float &ThermostaticSteam Trap

Air Vent

MoistureSeparator

Strainer

TemperatureControlValve

Float &ThermostaticSteam Trap

Strainer

Pre-Heater

ToVent

SightGlass

Spira-tecLoss

Detector

Strainer

CoolReturn

ToVent

HeatedOutlet

CheckValve

Pipe toSafePlace

127

HOOK-UP DIAGRAMS

Figure II-84Flash Steam Condensing by Spray

Residual flash steam for which nouse can found often causes a nui-sance if vented to atmosphere, and ofcourse carries its valuable heat con-tent with it. This steam may becondensed by spraying in cold water,in a light gauge but corrosion resis-tant chamber fitted to the receiver

tank vent. If boiler feed quality wateris used, the warmed water and con-densed flash steam is added to thecondensate in the receiver andreused. Condensing water which isnot of feed water quality is kept sepa-rate from the condensate in thereceiver as shown dotted.

A self-acting, normally closed tem-perature control with sensor in thevent line can control the coolant flow.This minimizes water usage, andwhere condensed flash steam isreturned, avoids overcooling of thewater in the receiver.

Overflow

CoolingWater

BoilerMakeup

TankCentrifugal

Pump

TemperatureControl Sensor

Waste

(Alternate)

Strainer

Condensate Receiver

H.P. Condensate

Vent

Self ActingTemperature

Control

FlashCondenser

128

HOOK-UP DIAGRAMS

Figure II-86Culinary/Filtered Steam Station

Figure II-85Clean Steam Drip Station

Strainer with aFine Mesh Screen

Float &ThermostaticSteam Trap

Strainer

Spira-tecLoss

Detector

MoistureSeparator

CleanSteamSupply

Stainless SteelThermo-Dynamic

Steam Trap

Stainless SteelBall Valve

Product/MediaLine

Sanitary DiaphragmValve with Inlet

Drain Boss

1:120 min.

1:120 min.

Condensate Manifoldmust be free draining

A

B

Install valve “A” close toproduct/media line.Close-couple valves “A” and “B”

Stainless SteelThermo-Dynamic

Steam Trap

Plant SteamInlet

SampleCooler

Stainless SteelBall Valve

Stainless SteelBall Valve

Steam Filterwith a 2.8 micron

absolute filterelement

AB

A All piping, fittings, valves, etc. downstreamof this point shall be of austenitic stainlesssteel and of sanitary design

B Recommended position of plant steampressure reducing valve if required

Pressure gauges, fittings, valves, etc., are notshown for clarity.

SanitaryCheck Valve

CoolingWaterOutlet

CoolingWaterInlet

CooledSample

129

HOOK-UP DIAGRAMS

Figure II-87 Tank Sterilization

Figure II-88Block and Bleed Sterile Barriers

Stainless SteelThermostaticSteam Trap

CleanSteamSupply

Product Outlet

DiaphragmValve

Stainless SteelBall Valve

Stainless SteelThermostaticSteam Trapinstalled as

Air Vent

Stainless SteelBall Valve

Stainless SteelBall Valve

Condensate

DiaphragmValve

DiaphragmValve

DiaphragmValve

Stainless SteelBall Valve

Stainless SteelThermo-Dynamic

Steam Trap

Stainless SteelThermostaticSteam Trap

AsepticProcess

Line

Sanitary DiaphragmValve with inlet Drain Boss

AsepticProcess

Line

Condenate Manifoldmust be free draining

SanitaryDiaphragm

Valve SanitaryDiaphragm

Valve

Stainless SteelBall Valve

1:120 min.

CleanSteamSupply

A

A Close-couple valves

130

HOOK-UP DIAGRAMS

Figure II-89Product/MediaProcess Line Sterilization

Figure II-90Pressure Regulating Stationfor Pure Steam Service

Figure II-91Sterilizer Utilizing High Purity Steam

Stainless SteelThermostaticSteam Trap

Product/MediaLine

Sanitary DiaphragmValve with inlet Drain Boss

CondenateManifold

must be freedraining

SanitaryDiaphragm

Valve

Stainless SteelBall Valve

1:120 min.

CleanSteamSupply

A

A Close-couple Diaphragm Valves

Stainless SteelBall Valve

Stainless SteelThermo-Dynamic

Steam Trap

Stainless SteelBall Valve

Stainless SteelBall Valve

Stainless SteelSteam Separator

SanitaryPressureRegulator

ReducedSteam

Pressure

Stainless SteelBall Valve

PureSteamSupply

See Fig. II-85for proper CleanSteam hook-up

to product/medialine

A

Stainless SteelThermo-Dynamic

Steam Trap

Stainless SteelBall Valve

Stainless SteelSteam Separator

PureSteamSupply

Stainless SteelBall Valve

SanitaryPressureRegulator

Stainless SteelThermo-Dynamic

Steam Trap

Stainless SteelBall Valves

Stainless SteelBall Valve

Stainless SteelBall Valve

StainlessSteel

Ball Valve

Stainless SteelThermostaticSteam Trapinstalled asan Air Vent

Stainless SteelThermostaticSteam Trapinstalled asan Air Vent

Stainless SteelBall Valves

Stainless SteelThermostaticSteam Traps

Stainless SteelBall Valves

Note: Provide over pressure protection forchamber and jacket with properly sizedsafety valve(s) or rupture disc(s).

Sterilizer

131

HOOK-UP DIAGRAMS

Figure II-92Spiraflo Saturated Steam (DensityCompensated) Metering System

Figure II-93Typical Superheated Steam (Density Compensated) Metering System

ThermostaticAir Vent

Float &ThermostaticSteam Trap

Strainer

SteamSeparator

IsolatingValve

CheckValve

SpirafloSteam Meter

Gilflo Meter

IsolatingValve

IsolatingValve

PressureTransmitter

FlowComputer

DifferentialPressure

Transmitter

3-ValveManifold

TemperatureTransmitter

Note: The same configuration issuitable for the Standard Range Gilflo,Gilflo ILVA and Orifice Plate Systems.

SteamSupply

Pipe toSafePlace

SteamSupply

CheckValve

SignalConditioning

Unit

FlowComputer

132

HOOK-UP DIAGRAMS

Figure II-94Typical Saturated Steamor Liquid Metering System(No Density Compensation)

Figure II-95Typical Saturated Steam(Density Compensated)Metering System

Figure II-96Typical Saturated Steam(Density Compensated)Metering System

Orifice Plate

IsolatingValve

IsolatingValve

FlowIndicator

DifferentialPressure

Transmitter

3-ValveManifold

Note: The same configuration issuitable for the Gilflo, Standard RangeGilflo, and Gilflo ILVA Systems.

Note: The same configuration issuitable for the Gilflo, Standard RangeGilflo, and Orifice Plate Systems.

For Saturated Steam, DensityCompensation is achieved by theflow computer accepting a signal fromeither a Temperature Transmitter(as shown here) or a PressureTransmitter (see Fig. II-96)

Gilflo ILVA

IsolatingValve

IsolatingValve

FlowComputer

DifferentialPressure

Transmitter

3-ValveManifold

TemperatureTransmitter

Gilflo ILVA

IsolatingValve

IsolatingValvePressure

Transmitter

FlowComputer

DifferentialPressure

Transmitter

3-ValveManifold

Note: The same configuration issuitable for the Gilflo, Standard RangeGilflo, and Orifice Plate Systems.

For Saturated Steam, DensityCompensation is achieved by the flowcomputer accepting a signal fromeither a Pressure Transmitter (asshown here) or a TemperatureTransmitter (see Fig. II-95)

SteamSupply

Steamor LiquidSupply

SteamSupply

133

HOOK-UP DIAGRAMS

Figure II-97Hand Operated Rotary Filter

Figure II-98Motorized Rotary Filter with Single Blowdown Valve

Figure II-99Control Panel Hook-up for One Valve Blowdown VRS-2 Rotary Filter System

MainPower

D.P.Switch

MotorWiring

Model VRSControl Panel

ValveWiring

InletPressure

Line Model VRS-2Rotary Filter

ReservoirPipe

RemovedSolids

RemovedSolids

DirtyMedia

Hand OperatedRotary Filter

FilteredMedia

HandOperatedBlowdown

Valve

RemovedSolids

DirtyMedia

MotorizedRotary Filter

FilteredMedia

Full PortQuarter Turn

Motorized Valve

Electric Supplyto Motor

Electric Supply toMotorized Valve

ReservoirPipe

Control of rotor and blowdownvalve is made with user sup-plied timers. The blowdownvalve should stay open forapproximately 10 seconds topurge filtered dirt and debrisfrom reservoir pipe. Intervaland duration of the rotor andblowdown valve will varydepending on the nature andquantity of the dirt and debris.

Full PortQuarter Turn

MotorizedValve

P1 P2Outlet

PressureLine

The Control Panel with useradjustable timers controls intervaland duration of the rotor and blow-down valve operation. The blowdownvalve opens for approximately 10

seconds to purge the reservoir pipeof filtered dirt and debris. The ControlPanel is shown with optional cyclecounter and differential pressureswitch which will activate rotor opera-

tion if excessive pressure dropoccurs. This hook-up illustrates anautomatic filtration system, providingcontinuous production flow with mini-mal product loss.

134

HOOK-UP DIAGRAMS

Figure II-100Control Panel Hook-up and Operation of Two Valve Blowdown VRS-2 Rotary Filter System

Figure II-101Motorized Rotary Filter withThree Valve Blowdown Systemfor Viscous FLuids

The Control Panel operates rotor andblowddown valves CV1 and CV2automatically. Fig. II-100A shows thenormal running mode with CV1 valveopen and CV2 valve closed, to allowreservoir to fill with dirt and debris. As

the reservoir pipe fills, valve CV1closes and valve CV2 opens purgingonly material held in the reservoir leg,Fig. II-100B. CV2 closes and CV1reopens returning system to normalrunning mode with no stoppage of

flow. This hook-up illustrates an auto-matic filtration system, providingcontinuous product flow with virtuallyno loss of usable fluid.

MainPower

D.P.Switch

MotorWiring

Model VRSControl Panel

ValveWiring

InletPressure

LineModel VRS-2Rotary Filter

ReservoirPipe

MainPower

D.P.Switch

MotorWiring

Model VRSControl Panel

ValveWiring

InletPressure

LineModelVRS-2

Rotary Filter

ReservoirPipe

MainPower

D.P.Switch

MotorWiring

Model VRSControl Panel

ValveWiring

InletPressure

LineModelVRS-2

Rotary Filter

ReservoirPipe

RemovedSolids

RemovesSolids

RemovedSolids

Full PortQuarter Turn

MotorizedValves

HighPressure

PurgeSee Fig. II-100A and II-100B for sequence ofoperation. In addition tothe blowdown valves onthe reservoir pipe, a thirdvalve CV3 has been addedfor a high pressure purgefluid or air should thedebris in the reservoir pipeprove to be too viscous toflow by gravity.

P1 P1P2P2

CV1

CV2

CV1

CV2

Full PortQuarter Turn

MotorizedValve

Full PortQuarter Turn

MotorizedValve

Figure II-100A Figure II-100B

OutletPressure

Line

OutletPressure

Line

P1 P2

CV1

CV2

CV3

OutletPressure

Line

135

HOOK-UP DIAGRAMS

Figure II-102Freeze Proof Safety Showerwith Antiscalding Protection

Figure II-103Automatic Contol of Smaller CompressorCooling with Overheat Protection

The T-44 control valve incorporates a bypass needle valve to keep a mini-mum flow of water past the sensor even when the main valve has closed.A float-type drainer is preferred for the separator rather than a TD drainer,to ensure immediate and complete drainage of the separated liquid.Larger compressors or low pressure cooling water supplies may call for aseparate supply of water to the aftercooler, with a solenoid valve orsimilar, to open when the compressor runs.

Fit T-44 control (withbypass closed), 85˚Fto 135˚F range, in 1-1/4” or larger pipe.Flow crosses sensorto shower, to coolingvalve inlet ending atthe #8 that openswhen ambient dropsbelow 40°F. Line flowprevents both freezeup and solar over-heating.

Drain

Strainer

LiquidDrainTrap

Air Line

MoistureSeparator

Strainer

CoolingControl

FloatOperatedAir Vent

CoolingWater

WarmedCoolant

CompressorJacket

AfterCooler

WaterSupply

#8 set@ 40°F

Strainer

CoolingControl

Spring ClosedValve To

Shower Head

OverheatDrain

136

HOOK-UP DIAGRAMS

Figure II-104Condensate Cooling System

Figure II-105Condensate Cooling and Flash Knockdown System

CoolingControlValve

Sensor

VacuumBreaker

VacuumBreaker

To Drain140°FMax.

Flash Tank

CondensateReturn

CoolingWater

ToVent

Sparge Pipe

CoolingControlValve

Sensor

To Drain140°FMax.

Flash Tank

CondensateReturn

CoolingWater

ToVent

Spray Nozzle

137

HOOK-UP DIAGRAMS

Figure II-106Continuous Boiler BlowdownCooling System

Figure II-107Controlling Coolant Flow to Vacuum StillCondenser and Draining Evaporator

Float & ThermostaticSteam Trap

Strainer

Evaporator

Self ContainedTemperature

Control

Spira-tecLoss

Detector

Thermo-DynamicSteam Trapwith Integral

Strainer

Spira-tecLoss

Detector

Condenser

ColdWaterSupply Waste Water

Sight Drain

Distillate

Strainer

Steam Main

CoolingControlValve

Sensor

VacuumBreaker

ContinuousBoiler

Blowdown

CoolingWater

BlowdownVessel

ToVent

SpargePipe

To Drain140°FMax.

GravityCondensate

Return

VentHead

138

HOOK-UP DIAGRAMS

Figure II-108ControllingTemperatureof Ball GrindingMill Jacket

Figure II-109Controlling Temperature of Oil Cooler

Figure II-110Controlling Temperature of Horizontal Solvent Condenser

Strainer

ColdWaterSupply

CoolerFilter

Drain

Hot Solvent

CoolingWaterOut Cooled

SolventCoolingWater

Discharge

Self ContainedCooling Control

SightDrain

Strainer

Cool Oil

Oil Cooler

Hot Oil

Self ContainedCooling ControlCold

WaterSupply

Strainer

Grinding Mill

CoolingControl ValveCold

WaterSupply

SightDrain

WaterJacket

TemperatureControlSensor

SightDrain

CheckValve

139

HOOK-UP DIAGRAMS

Figure II-112Cooling Water Economizerfor Multiple Rolls

Figure II-111Controlling Temperatureof Vertical Solvent Still

Strainer

Self ContainedCooling Control

CoolingWater

Discharge

Roll

Roll

Roll

FloatOperatedAir VentCold

Water

Perforated PipeHoles Pointing Down

Mixing Tank

CentrifugalPump

FlowBalancing

Valve

Strainer

ColdWaterSupply

Cooler

Solvent

Filter

Drain

Drain

Self ContainedCooling Control

Solvent toEquipment

Pipe WasteWater

To Drain

CheckValve

Drain

140

HOOK-UP DIAGRAMS

Figure II-113Alternate Methods of Draining Compressed Air Receiver

Figure II-114Draining Compressed AirDropleg to Equipment

Figure II-115Draining Riser in CompressedAir Distribution Line

Strainer

LiquidDrainTrap

LiquidDrainTrap

Strainer

Equipment Supply

Main

Drain Drain

Main Supply

BalanceLine

Branches are best takenoff the top of main lines.Condensation sweptalong the lines when airtools are used may over-load the filter of the airset at the take-off point,so a drainer is providedat the bottom of the sup-ply leg to remove asmuch as possible of thiscondensation.

Balance lines are notalways necessary onAir Drainers. Theybecome necessarywhen the trap locationis more remote fromthe line being drainedand when condensa-tion quantities aregreater. It is preferredto connect balancelines downstream ofthe point beingdrained.

LiquidDrainTrap Strainer

Balance Line

LiquidDrainTrap

Strainer

Air Receiver

Small air receivers are often“drained” through a manual valve atlow level on a once per day basis.Continuous drainage helps to main-tain better quality in the air supplied

but small receivers may be mountedso low as to preclude the use of theCA14 or FA pattern drainers. Thedrain point may be in the center of the

dished end of even on top, with aninternal dip pipe to reach the collect-ed liquid. The only possible option isthe TD drainer.

141

142

PRODUCTINFORMATION

Section 3

Product Information

144

• Pressure Powered Pumps™ • Packaged Pressure Powered Pumps™

• High Capacity Pressure Powered Pump™ • Electric PumpsSpirax Sarco offers the solutions to maintaining efficiency in all areas of

condensate recovery. For the total system solution, Spirax Sarco’s non-electricpumps drain and return condensate and other liquids from vacuum systems,condensers, turbines, or any other steam condensing equipment. The PressurePowered Pump™ can handle liquids from 0.65 to 1.0 specific gravity and capac-ities up to 39,000 lb/hr. Available in cast iron or fabricated steel (ASME codestamped) with stainless steel internals and bronze or stainless steel checkvalves, the rugged body allows a maximum pressure of 125-300 psig and a max-imum temperature of 450˚F. This system solution saves energy and providesoptimum system efficiency with low maintenance.

For easy installation, Pressure Powered Pump™ packaged units are pre-piped and combine any Pressure Powered Pump™, up to 3" x 2" with a receiver.

Spirax Sarco’s electric pumps are packaged units completely assembled,wired and tested. Electric condensate return pumps are available in simplexunits with an integral float switch or a mechanical alternator on the duplex units.

• Automatic Control Valves• Direct Operated Temperature Regulators• Direct Operated Pressure Regulators• Pilot Operated Temperature Regulators• Pilot Operated Pressure Regulators• Safety Valves

Maximum productivity requires delivering the steam at its most energyefficient pressure and temperature resulting in optimum energy usage, and asafe, comfortable environment. Spirax Sarco has a complete range of controls toefficiently provide the right heat transfer for any process or heating application.

Ranging in sizes from 1/2" to 6", operating pressures up to 600 psi, andcapacities up to 100,000 lb/hr, the complete range of controls and regulatorsprovide steam system solutions industry wide. Available in iron, steel, stainlesssteel, and bronze, Spirax Sarco controls and regulators are suitable for virtuallyall control applications.

Controls & Regulators

• Steam Trap Surveys • Model VRS Control Panel• Steam System Audits • Steam System Management• Contracted Site Management

When the question is steam the answer is Spirax Sarco. Strategic alliances with SpiraxSarco have benefited many of the world’s largest steam users through energy savings, processimprovement and out sourcing of non-core activities.

Service Capabilities

Condensate Recovery

PRODUCT INFORM

ATION

Product Information

145

• Balanced Pressure Thermostatic • Bimetallic• Float & Thermostatic • Inverted Bucket• Thermo-Dynamic® • Liquid Expansion• Steam Trap Fault Detection Systems • Steam Trap Diffuser

Spirax Sarco designs and manufactures all types of steam traps in a varietyof materials. Whether it be for steam mains, steam tracing, or heating and pro-cessing equipment, Spirax Sarco has the knowledge, service and products toimprove your steam system.

Mechanical steam traps are available in iron and steel with NPT, socketweld, or flanged connections in sizes ranging from 1/2" to 4". Thermostatic typesare available in brass, forged steel, stainless steel, cast alloy steel with stainlesssteel internals with NPT and socket weld connections and are available in sizes1/2" to 1-1/2". The kinetic energy disc types are available in stainless, alloy andforged steel and range in sizes from 1/2" to 1" with NPT, Socket Weld and ANSIconnections.

Steam Traps

Many industrial processes involve the removal of a liquid from a pressurizedgas. Spirax Sarco Liquid Drain Traps are ideally suited for this purpose as wellas removing condensate from compressed air lines. The float operated designinstantly and automatically adjusts to variations in liquid load and pressure.

The traps can handle liquids with a specific gravity as low as 0.5. LiquidDrain Traps have a maximum operating pressure to 465 psi and range in sizefrom 1/4" to 4" with capacities of up to 900,000 lb/hr. Construction is cast iron,ductile iron, carbon steel or 316L stainless steel bodies with NPT, socket weld orflanged connections.

Liquid Drain Traps

• Flash Vessels • Steam Separators• Strainers - Pipeline and Basket • Sight Glasses/Checks• Air Handling Equipment • Trap Diffusers• Radiator Valves • Vent Heads• Ball Valves • Vacuum Breakers• Steam Injectors

The Spirax Sarco line of Pipeline Auxiliaries complete the steam system and areavailable in a variety of materials and sizes to suit your needs.

Pipeline Auxiliaries

PRODUCT INFORM

ATION

Product Information

146

A comprehensive range of stainless steel products:• Steam Traps • Separators • Hygienic Ball Valves• Pressure Controls • Filters • Sample Coolers

The use of clean or pure steam to reduce the risk of product or processcontamination spans many industries and applications, including pure steam forsterilization of equipment in the biotechnology and pharmaceutical industries,culinary steam for direct cooking and heating of foods, clean steam for humidifi-cation of clean rooms, and filtered steam for hospital sterilizers. Spirax Sarco’srange of stainless steel specialty products have been designed and manufac-tured to the highest standards and specifications required to withstand the rigorsof service in clean steam and other aggressive process fluids.

Stainless Steel Specialty Products

Complete modular solutions for steam users worldwide:• Preassembled Steam Trap Stations• Steam Distribution and Condensate Collection Manifolds• Forged Steel Manifolds• Process Condensate Removal Modules• Condensate and Flash Steam Recovery Modules

From institutional condensate recovery applications to draining critical processheat transfer equipment, Spirax Sarco’s modular pumping systems are the mostcost effective and provide the lowest total installed cost. The conventional methodof individually specified and procured components with on-site assembly is laborintensive and not conducive to today’s competitive plant standards.

The Engineered Systems Advantage expedites the installation process anddelivers a quality solution to numerous types of steam users. Each modularpumping system utilizes reliable Pressure Powered Pump™ technology andsaves 25% over the conventional method. Spirax Sarco backs each unit with asole source guarantee and unequaled expertise in steam system technology.

Engineered Systems

Years of accumulated experience has enabled the development and nurtur-ing of in-depth expertise for the proper control and conditioning of steam.Experienced field personnel work closely with design, operations, andmaintenance engineers, continuously evaluating ways to improve productivity.Often, these solutions pay for themselves many times over.

The four U.S. training centers located in Chicago, Houston, Los Angeles,and Blythewood, SC, have on-site steam systems providing hands-on training.Education programs include the theory of steam, the application of steamproducts, and plant design and system efficiency, to name just a few. Programsalso can be tailored to meet individual needs. Thousands of engineers completeSpirax Sarco training programs each year and return to continue broadeningtheir knowledge of steam systems.

TrainingPRODUCT IN

FORMATION

147

148

Subject Index

PageAbsorption Chiller .............................................................................................................................................................................36, 102After Coolers ...........................................................................................................................................................................................135Air Compressor .........................................................................................................................................................................................62Air Compressor Cooling....................................................................................................................................................................62, 135Air Eliminators on Liquid Service............................................................................................................................................118, 135, 139Air Heating Coils .................................................................................................................................................30-37, 95, 96, 97, 98, 113Air Leakage from Comp. Air System.........................................................................................................................................................64Air Drainer Traps .......................................................................................................................................................................62, 135, 140Air Venting (see Vents, Air for Steam Spaces)Autoclaves...............................................................................................................................................................................................103

Back Pressure Control (see Pressure Control Valves)Back Pressure, Effect on Trap Cap.......................................................................................................................................................9, 46Balance Valves..........................................................................................................................................................................................30Baseboard Radiation ..............................................................................................................................................................................107Batch Processor, Automatic Control .......................................................................................................................................................103Blenders and Three-Port Valves ...................................................................................................................................................28, 29, 30Blowdown, Continuous............................................................................................................................................................................137Boiler Feed Water Heating......................................................................................................................................................104, 105, 127Boiler Steam Header Drainage.......................................................................................................................................................8, 84, 92Boiler Working Pressure .........................................................................................................................................................................2, 9

Clean SteamCharacteristics ..................................................................................................................................................................................51Definitions .........................................................................................................................................................................................50Distribution ........................................................................................................................................................................................51Generation ........................................................................................................................................................................................50Requirements....................................................................................................................................................................................52System Design.............................................................................................................................................................................52-53

Clean Steam ApplicationsBlock and Bleed Sterile Barriers...............................................................................................................................................53, 129Condensate Drainage.......................................................................................................................................................................54Drip Stations ...................................................................................................................................................................................128Filtered Steam Stations ............................................................................................................................................................55, 128Pressure Regulation .......................................................................................................................................................................130Process Line Sterilization ...............................................................................................................................................................130Tank Sterilization.............................................................................................................................................................................130Sterilizers ........................................................................................................................................................................................129

Hospitals ...................................................................................................................................................................................54Using Pure Steam...................................................................................................................................................................130

Closed Loop System.................................................................................................................................................................................35Co-efficients, Heat Transfer.................................................................................................................................................................33, 67Coils,

Air Heater ................................................................................................................................................................30-37, 95, 97, 113Fan Coil Unit .....................................................................................................................................................................................98High Pressure, Draining .....................................................................................................................................................35, 97, 113Pre-heat and Re-heat .................................................................................................................................................................32, 96

Combination Pump/Traps.............................................................................................................35, 49, 95, 101, 102, 112, 115, 116, 117Compressed Air Drainers .........................................................................................................................................................62, 135, 140

Pipe Sizing............................................................................................................................................................................63, 64, 66Services ......................................................................................................................................................................................62, 63

Compressor Cooling....................................................................................................................................................................64-65, 135Condensate—Calculating Loads ....................................................................................................................................................9, 10, 24

Collecting Legs .......................................................................................................................................................................8, 11, 38Coolers....................................................................................................................................................................................136, 137Discharge into Plastic or Fiberglass Line .........................................................................................................................................87Lifting to Main at Same Level ...........................................................................................................................................................86Lifting from Trap to High Level ..........................................................................................................................................................86Lifting to Trap at High Level ..............................................................................................................................................................87Loads from Steam Mains..............................................................................................................................................................9, 10Pumped Returns..........................................................................................................................................................................47-49Sizing Return Lines .....................................................................................................................................................................43-47

Condenser, Solvent Control ............................................................................................................................................................138, 139Controls

Back Pressure or Surplussing (see Pressure Control Valves)Combination, Pressure Reducing/Electric ......................................................................................................................................104Combination, Pressure Reducing/Temperature......................................................................................................................100, 104Combination, Pressure/Temperature/Electric .................................................................................................................................103Definitions ...................................................................................................................................................................................23, 28Pilot Operated Electric ..............................................................................................................................................................94, 107Pressure Reducing (see Pressure Control Valves)

149

Subject Index

Safety ................................................................................................................................................................................................98Sizing...................................................................................................................................................................................3, 4, 23-30Temperature (see Temperature Control Valves)

Convectors ..............................................................................................................................................................................................107Conversion Tables...............................................................................................................................................................................74, 75Coolers............................................................................................................................................................................................135, 138Corrosion ..................................................................................................................................................................................................32Culinary Steam (see Filtered Steam)Cv ........... .....................................................................................................................................................................................23, 25, 29Cylinders, Rotating..........................................................................................................................................................................111, 112

Direct InjectionSteam .................................................................................................................................................................27, 28, 104, 105, 106Water ..............................................................................................................................................................................136, 137, 139

Drain Traps, Air and Gases.......................................................................................................................................................62, 135, 140Dryers ........................................................................................................................................................................................111, 112Dyeing Equipment...................................................................................................................................................................................103

Elevating Condensate byElectric Pump..................................................................................................................................................................................119Non-electric Pump...........................................................................................................................114, 115, 116, 117, 118, 121-126Line Pressure........................................................................................................................................................................................

Engine—Jacket Temperature Control .....................................................................................................................................................135Evaporators.....................................................................................................................................................................................115, 137Exchanger—Heat ...............................................................................................................................93, 99, 100, 101, 123, 124, 125, 126Expansion Loops, Draining .......................................................................................................................................................................85Expansion of Pipes ...................................................................................................................................................................................66

Filtered Steam...................................................................................................................................................................................50, 103Filtration (Rotary Filters) .................................................................................................................................................................133, 134Flash Steam.....................................................................................................................................................................................3, 41-47Flash Steam, Recovery Hookups ............................................................................................97, 120, 121, 122, 123, 124, 125, 126, 127Flowmeters (see Steam Meters)Freeze Resistant Hookups........................................................................................................................................................96, 110, 135

Gilflo (see Steam Meters)Gilflo I.L.V.A. (See Steam Meters)Grinding (Ball) Mill Jacket Temperature Control .....................................................................................................................................137

Heat Exchangers (see Exchangers)Heaters, Air.......................................................................................................................................................................36, 37, 95, 97, 98Heaters, Hot Water Storage................................................................................................................................................................98, 99High Limit Overheat Protection.................................................................................................................................................................98Hospital Equipment.........................................................................................................................................................................108, 109Hot Water Blending.......................................................................................................................................................................28, 29, 30

Ironer, Flatwork .......................................................................................................................................................................................111

Kettle, Jacketed.......................................................................................................................................................................................113

Lift Fitting ................................................................................................................................................................................................103Liquid Flowmeters (see Steam Meters)Low Pressure Steam Main Drainage ........................................................................................................................................................84

MainsAir .............................................................................................................................................................................................62-66Condensate Return (see Condensate)Piping Sizing...............................................................................................................................................................................3, 4, 6Steam

Air Venting (see Vents, Air for Steam)Automatic Heatup .................................................................................................................................................................9, 94Collecting Leg Sizing ................................................................................................................................................................11Condensate Loads................................................................................................................................................................9, 10Draining ........................................................................................................................................................................11, 38, 45Draining End of HP Lines .........................................................................................................................................................85Draining End of LP Lines..........................................................................................................................................................84Draining Boiler Header .........................................................................................................................................................8, 92Draining Expansion Loops........................................................................................................................................................85Draining Mains to Return to Same Level..................................................................................................................................86Draining Main, Automatic Startup.....................................................................................................................................8, 9, 86Draining Main, Supervised Startup ......................................................................................................................................8, 86Draining Main, with Trap at Higher Level ............................................................................................................................86, 87

Subject Index

150

NPSH Calculations ...................................................................................................................................................................................48

Oil Cooler—Temperature Control............................................................................................................................................................138Orifice Plate Flowmeters (see Steam Meters)Overheat Protection of HW Storage Cylinder ...........................................................................................................................................98Overheat Protection of Reinforced Plastic Condensate Lines..................................................................................................................87

Paper Machines ......................................................................................................................................................................................112Parallel Operation of Pressure Reducing Valves ................................................................................................................................21, 89Pipe & Flange Dimensions .................................................................................................................................................................80, 81Platen Press....................................................................................................................................................................................104, 110 Plating Tanks...........................................................................................................................................................................................103Preheat and Reheat Coils.........................................................................................................................................................................96Presses, Laundry............................................................................................................................................................................110, 111Pressure Drop

in Steam Mains.......................................................................................................................................................................2, 3, 4, 5in Water Lines .............................................................................................................................................................................76, 77in Air Lines ........................................................................................................................................................................................66in Water Fittings ................................................................................................................................................................................79

Pressure Powered PumpClosed System.......................................................................................................................35, 49, 95, 99, 101, 102, 112, 116, 117Discharging to Long Delivery Line............................................................................................................................................47, 118Discharging to Long Delivery Line with Lift at Remote End ...........................................................................................................118Draining Air Heater Coil........................................................................................................................................................95, 97, 98Draining Condensed Flash Steam with Other LP Condensate ........................................................................................48, 123, 125Draining Evaporator as Pumping Trap ............................................................................................................................................115Draining Equipment Near Floor Level.....................................................................................................................................116, 117Draining Flash Steam Recovery Vessel ...........................................................................................................97, 121, 123, 125, 126Draining Large Heater ..............................................................................................................................................................97, 101Draining LP Heater to Overhead Main .............................................................................................................................................99Draining Condensate from Vacuum........................................................................................................................................115, 119Draining Water from Sump Pit ........................................................................................................................................................118Hookup for Staged & Standby Operation .......................................................................................................................................117Lifting Atmospheric Condensate to Overhead Main .......................................................................................................................114Lifting from LP Source to HP Receiver...........................................................................................................................................116Modules....................................................................................................................................................95, 101, 112, 121, 122, 123Pumping Condensate from Small Heater & Other Loads...............................................................................................................100Pumping Preheater & Reheater Condensate ...................................................................................................................................96Vented System.....................................................................................................................49, 96, 97, 100, 101, 102, 114, 117, 121

Pressure Reducing ValvesBack Pressure ...............................................................................................................................................22, 92, 97, 104, 120-126Combined Pressure/Temp. Control of Heat Exchanger..................................................................................................................100Control of Batch Processor with Electric Programmer ...................................................................................................................103Controlling Boiler Feed Water Temp. Using Pressure/Temperature Control ...................................................................................104Controlling Live Steam Makeup to Flash Steam Recovery............................................................................................120, 121, 122Controlling Platen Press. ................................................................................................................................................................104Direct Operated Valves ...............................................................................................................................................................19, 91Installation in Tight Spaces...............................................................................................................................................................91Low Capacity PRV Station................................................................................................................................................................91Noise Considerations........................................................................................................................................................................19Parallel PRV Station .......................................................................................................................................................20, 21, 22, 89Pilot Operated Valves ............................................................................................................................................19, 94, 97, 120-122Pneumatically Operated Valves ..................................................................................................................................................19, 93PRV for Motive Steam ......................................................................................................................................................................94PRV Station Components .................................................................................................................................................................20Remote Air Pilot Control of PRV.......................................................................................................................................................92Remote Operation of PRV’s........................................................................................................................................................90, 92Sizing............................................................................................................................................................................3, 4, 23, 24, 25Two-Stage PRV Station ........................................................................................................................................................20, 22, 90Typical Pressure Reducing Valve Station ...................................................................................................................................20, 89

Pressure/Temperature Control (see controls)Programmers

On Supply to Platen Press .............................................................................................................................................................104Mains Heatup, Pressurizing and Shutdown..................................................................................................................................9, 94Batch Processor Sequencing .........................................................................................................................................................103

Psychrometric Chart .................................................................................................................................................................................78Pumping Trap (see Pressure Powered Pump)Pumps, Electrical ................................................................................................................................................................47, 48, 119, 127Pumps, Packaged Units ...........................................................................................................97, 100, 101, 102, 112, 121, 122, 123, 124Pure Steam ...............................................................................................................................................................................................50Pyrometers................................................................................................................................................................................................55

Subject Index

151

Radiation—Baseboard Fin Tube, Hot Water and Steam ........................................................................................................................107Reboiler, Draining HP Condensate.........................................................................................................................................................114Receiver, Compressed Air, Drainage......................................................................................................................................................140Reducing Valves (see Pressure Reducing Valves)Reheat-Preheat Coil .................................................................................................................................................................................96Remote Opertion of Controls........................................................................................................................................................90, 92, 93Return Lines, Hot Water .....................................................................................................................................................................45, 47Rotating Cylinders...................................................................................................................................................................................111Running Load, Steam Main ..................................................................................................................................................................9, 10

Safety Factors for Steam Traps.............................................................................................................................................................9, 39Safety Relief Valve Sizing .........................................................................................................................................................................20Safety Showers .......................................................................................................................................................................................135Scrubber, Natural Gas, Drainage............................................................................................................................................................116Separators

Air ................................................................................................................................................................................................135Steam .............................................................................................8, 19, 60, 89, 90, 91, 92, 93, 95, 97, 98, 99, 100, 101, 103, 104,

105, 107, 108, 120, 121, 122, 125, 128, 130, 131Series Opertion of Reducing Valves .........................................................................................................................................................90Sight Glasses............................................................................................................................................................................................55Sizing

Air Lines................................................................................................................................................................................63, 64, 66Compressed Air Drainers .................................................................................................................................................................62Condensate Lines...........................................................................................................................................................43, 45, 46, 47Control Valves.......................................................................................................................................................................23, 24, 25Flash Steam Recovery Vessels ..................................................................................................................................................42, 43Sparge Pipes ..............................................................................................................................................................................27, 47Steam Mains.........................................................................................................................................................................2, 3, 6, 11Steam Traps................................................................................................................................................................9, 16, 38, 39, 40Vent Lines ...............................................................................................................................................................................3, 42, 43Water Lines.....................................................................................................................................................................45, 76, 77, 79

Solvent Cooler—Temperature Control ....................................................................................................................................................138Sparge Pipe Sizing ...................................................................................................................................................................................27Specific Heat of

Solids ................................................................................................................................................................................................70Liquids...............................................................................................................................................................................................71Gases................................................................................................................................................................................................71Foodstuffs ...................................................................................................................................................................................72, 73

Spiratec Leak Detector System ..........................................................................................................................................................56, 58Standard Range Gilflo (SRG) (see Steam Meters)Stall Chart ...........................................................................................................................................................................................33, 34Steam Consumption Rates.................................................................................................................................................................68, 89Steam Injection...........................................................................................................................................................27, 28, 104, 105, 106Steam Mains (see Mains)Steam Meters

Accuracy ...........................................................................................................................................................................................59Density Compensation......................................................................................................................................................................60Installation.........................................................................................................................................................................................60Liquid Metering System ..................................................................................................................................................................132Meter Location ..................................................................................................................................................................................61Repeatability .....................................................................................................................................................................................59Steam Conditioning...........................................................................................................................................................................60Spiraflo Saturated Steam Metering System ...................................................................................................................................131Saturated Steam Metering System.................................................................................................................................................132Steam Conditioning Station ..............................................................................................................................................................60Superheated Steam Metering System............................................................................................................................................131Turndown ..........................................................................................................................................................................................59

Steam Lines, Draining...............................................................................................................................................................................85Steam Needs Analysis Program (SNAP)..................................................................................................................................................39Steam Purity .............................................................................................................................................................................................51Steam Quality ...........................................................................................................................................................................................51Steam Tables ..............................................................................................................................................................................................7Steam Tracing ................................................................................................................................................................................12-18, 88Steam Traps (see Traps, Steam)Sterilizer Hookup.............................................................................................................................................................................108, 109Sterilizer, Trapping and Air Venting .........................................................................................................................................................108Still Condensers, Cooling Control ...........................................................................................................................................................137Storage Tank Heating .................................................................................................................................................................98, 99, 110Sump Pit Drainage..................................................................................................................................................................................118Superheated Steam ....................................................................................................................................................................................6Surplussing Valve (see Back Pressure Control)System Stall..................................................................................................................................................................................33, 34, 35

Subject Index

152

TanksBoiler Feed Water ...........................................................................................................................................................104, 105, 127Flash (sizing) .........................................................................................................................................................................42-44, 49Flash Steam Recovery (see Flash Steam, Recovery Hookups)Hot Water Storage ......................................................................................................................................................................98, 99Open .......................................................................................................................................................................................103, 105Plating, Dyeing & Process ..............................................................................................................................................................103Product Storage..............................................................................................................................................................................110

Temperature Control ValvesCooling Service .........................................................................................................................................................87, 127, 135-139Direct Operated ......................................................................................................26-29, 87, 88, 105, 127, 135, 136, 137, 138, 139Heating Service (liquid).....................................................................................................................................................................26Heating Service (steam)......................................................26, 27, 28, 88, 97, 98, 99, 100, 101, 103, 104, 105, 106, 108, 125, 126Installation.........................................................................................................................................................................................27Pilot Operated ..........................................................................................................................26, 95, 96, 97, 99, 100, 103, 105, 106Pneumatically Operated ...............................................................................................................................................27, 28, 93, 101Remote Setting .................................................................................................................................................................................93Sizing ...........................................................................................................................................................................................23-30Three-Port (blending, diverting)............................................................................................................................................28, 29, 30Two-Port Direct Acting (heating) .....................................................................................................................26-29, 88, 98, 105, 108Two-Port Reverse Acting (cooling) .............................................................................................28, 87, 127, 135, 136, 137, 138, 139

Testing Steam Traps ............................................................................................................................................................................55-58Thermostatic Air Vents (see Vents, Air, for Steam Spaces)Three Port Valves .........................................................................................................................................................................28, 29, 30Tire Mold Hookup....................................................................................................................................................................................113Tracer Lines,

Control ............................................................................................................................................................................16, 17, 18, 88Trapping....................................................................................................................................................................15, 17, 18, 38, 88

Tracer Systems........................................................................................................................................................................12-18, 38, 88Trap Diffuser..............................................................................................................................................................................................47Traps, Drain...............................................................................................................................................................................47, 135, 140Traps, Steam

Discharge Modes..............................................................................................................................................................................56Location ..........................................................................................................................................................................11, 17, 32, 38Sanitary Clean Steam Systems .........................................................................................................................52, 53, 128, 129, 130Selection and Sizing...................................................................................................................................................9, 16, 38, 39, 40Steam Loss Estimates ......................................................................................................................................................................57Testing of .....................................................................................................................................................................................55-58

Unit Heater Drainage ................................................................................................................................................................................98

Vacuum Breakers ............................................................................31, 93, 96, 97, 98, 100, 104, 105, 110, 118, 123, 125, 126, 136, 137Vacuum—Draining Condensate from .............................................................................................................................................115, 119Valves

Accuracy (droop)...............................................................................................................................................................................23Balancing ..........................................................................................................................................................................................30Cv 23, 25, 29Definitions ...................................................................................................................................................................................23, 28Pressure (see Pressure Control Valves)Proportional Band.......................................................................................................................................................................23, 26Sizing...................................................................................................................................................................................3, 4, 23-30Temperature (see Temperature Control Valves)

Velocity,Steam Mains...........................................................................................................................................................................3, 4, 6, 8Water Mains................................................................................................................................................................................76, 77Air Lines......................................................................................................................................................................................63, 64

Vents, Air, for Steam Spaces ................................................11, 31, 60, 85, 95, 96, 97, 99, 100, 101, 102, 103, 104, 108, 109, 111, 113114, 115, 116, 117, 120, 123, 124, 125, 126, 129, 130, 131

Vortex Flowmeters (see Steam Meters)

Warmup Loads, Steam Main ................................................................................................................................................................9, 10Warmers, Blanket and Bedpan, Hospital ................................................................................................................................................108Washers, Egg..........................................................................................................................................................................................106Water For Injection (WFI)..........................................................................................................................................................................50Water Hammer......................................................................................................................................................................................8, 32Water Logging.....................................................................................................................................................................................31, 35

153

Group Companies and Sales Offices

ArgentinaSpirax Sarco S.A.Ruta Panamericana Km. 24,9001611 Don TorcuatoBuenos Aires, ArgentinaAustraliaSpirax Sarco Pty. LimitedP.O. Box 6308Delivery CentreBlacktownN.S.W. 2148, AustraliaAustriaSpirax Sarco Ges.m.b.H.Eisgrubengasse 2/PF 41A-2334 Vosendorf-Sud.AustriaBelgiumSpirax Sarco N. V.Industriepark Zwijnaarde 59052 Gent - ZwijnaardeBelgiumBrazilSpirax Sarco Ind. E Com LtdaRodovia Raposo Tavares Km. 31Caixa Postal 14306700-000. Cotia S.P.Brazil

CanadaSpirax Sarco Canada Limited383 Applewood CrescentConcordOntario L4K 4J3, Canada

ChinaSpirax Sarco Engineering (China) Ltd.No. 107 Gui Qing RoadCaohejing Hi Tech ParkShanghai, ChinaPostcode 200233

ColombiaSpirax Sarco Internacional LtdaApartado Aereo 32484Cali (Valle)Colombia, South America

Czech RepublicSpirax Sarco Spol. s. r. o.V korytech (areal nakladoveho nadrazi CD)100 00 Praha 10 StrasniceCzech Republic

DenmarkSpirax Sarco LimitedBirkedommervej - 312400-Copenhagen N.V., Denmark

East AfricaSpirax Sarco Limited3rd Floor (above Gilani’s)ABC Place, Waryaki WayWestlands, NairobiKenya

FinlandSpirax OySorvaajankatu 900810 Helsinki, Finland

FranceSpirax Sarco S.A.B P 61F 78193 TrappesCedex, FranceGermanySpirax Sarco GmbHPostfach 10 20 42D-78420 Konstanz, Germany

Hygromatik Lufttechnischer Apparatebau GmbHLise-Meitner-StraBe 3D-24558 Henstedt-UlzburgGermanyGreat BritainSpirax Sarco LimitedHead OfficeCharlton House, CheltenhamGloucestershire, GL53 8ERGreat BritainHong KongSee SingaporeHungarySpirax Sarco Ltd.11-1143 BudapestZászlós u. 18.HungaryIndiaSpirax Marshall LimitedP.B. No. 29Bombay Poona RoadKasarwadiPune 411 034, IndiaIndonesiaSee SingaporeItalySpirax Sarco SrlVia Per Cinisello, 1820054 Nova MilaneseMilano, ItalyJapanSpirax Sarco (Japan) Limited2-37, Hamada, MihamakuChiba 261-0025JapanKoreaSpirax Sarco Korea Limited3rd-5th Floor, Jungwoo Building1552-8 Seocho-dongSeocho-kuSeoul 137-070, KoreaLebanonSpirax Sarco Resident EngineerP.O. Box 11-3052Beirut, LebanonMalaysiaSpirax Sarco Sdn Bhd25, Jalan PJS 11/1Bandar Sunway46150 Petaling JayaSelangor Darul EhsanWest MalaysiaMexicoSpirax Sarco Mexicana S.A. de CVApartado Postal 5287-KMonterrey NL64000 - MexicoNew ZealandSpirax Sarco LimitedP.O. Box 76-160Manukau CityAuckland, New ZealandNigeriaSpirax Sarco Sales RepresentativeCakasa Company Ltd.96 Palm Ave.P.O. Box 871Mushin, Lagos, NigeriaNorwaySpirax Sarco Limited (Norge)P.O. Box 471483 Skytta, Norway

PakistanSpirax Sarco Sales Representative2-C Gulistan-E-Zafar P.R.E.C.H.S.Near SMCHS Block BPostal Code 74400Karachi, PakistanPolandSpirax Sarco Sp. z o.o.Fosa 2502-768 Warszawa, PolandPortugalSpirax Sarco-Equipamentos

Industrias Lda.Rua da Quinta do Pinheiro, 8Portela de Carnaxide2795-653 Carnaxide, PortugalRussiaSpirax Sarco Ltd.(Room 1401)4 Vozrozhdenija Str.198097 St. Petersburg, RussiaSingaporeSpirax Sarco Pvt. Limited464 Tagore AvenueUpper Thomson RoadSingapore 787833South AfricaSpirax Sarco (Pty) Ltd.P.O. Box 925Kempton Park 1620Transvaal, South Africa

SpainSpirax Sarco S.A.Sant Josep, 130Poligon El Pla08980 Sant Feliu de LlobregatSpain

SwedenSpirax Sarco ABVästberga Allé 60S-126 30 Haegersten, Sweden

SwitzerlandSpirax Sarco A. G.Gustav-Maurer-Str.98702 Zollikon, Switzerland

TaiwanSpirax Longbridge Limited6th FloorNo. 8, Lane 94, Tsao Ti WeiShen Keng HsiangTaipei CountyTaiwan, Republic of ChinaThailandSpirax Boonyium Limited9th Floor, Benjaporn Building222 Krungtep-kreetha RoadBangkapiBangkok 10240, Thailand

U.S.A.Spirax Sarco, Inc.Northpoint Park1150 Northpoint Blvd.Blythewood, SC 29016

Watson-Marlow Bredel Inc.220 Balladvale StreetWilmington, MA 01887

VenezuelaSpirax Sarco S.A.Apartado 81088Caracas 1080A, Venezuela

154

Regional Offices

NORTHEASTNigel SewellColumbus, Ohio, Hub Office7760 Olentangy River RoadSuite 120Columbus, OH 43235Phone: (614) 436-8055Fax: (614) 436-8479

MID-ATLANTICEd Beedle4647 Saucon Creek RoadSuite 102Center City, PA 18034Phone: (610) 807-3500Fax: (610) 317-3279

SOUTHEASTBruce Moninghoff200 Centre Port DriveSuite 170Greensboro, NC 27409Phone: (336) 605-0221Fax: (336) 605-1719

MIDWESTPierre Schmidt2806 Centre Circle DriveDowners Grove, IL 60515Phone: (630) 268-0330Fax: (630) 268-0336

SOUTHWESTJon Lye203 Georgia Ave.Deer Park, TX 77536Phone: (281) 478-4002Fax: (281) 478-4615

WESTMike Gillick1930 East Carson Street, Suite 102Long Beach, CA 90810Phone: (310) 549-9962Fax: (310) 549-7909