SASO 1585 STEAM BOILERS - PART 16: REQUIREMENTS FOR ...zb.guaihou.com/stdpool/SASO 1585-1999 Steam Boliers... · 4.1.9.1 The maintenance of boiler shall be controlled by a planned

SASO 1585

STEAM BOILERS - PART 16: REQUIREMENTS

FOR MAINTENANCE

First Edition 1419(H)-__-__ (1999-11-10)

STEAM BOILERS - PART 16: REQUIREMENTS FOR MAINTENANCE

ICS:

Date of SASO Board of Directors Approval : 09/06/1420-19/09/1999 Date of Publication in the Official Gazette : 04/08/1420-13/11/1999 Date of Enforcement of this Standard : 04/02/1421-08/05/2000

SAUDI STANDARD SASO 1585/1999

TABLE OF CONTENTS

Page 1. Scope and Field of Application ....................................................... 4 2. Complementary References ............................................................ 4 3. Definitions ..................................................................................... 4 4. Requirements ................................................................................. 7 4.1 General .......................................................................................... 7 4.2 Safety During Maintenance ............................................................ 12 4.3 Maintenance Checks ...................................................................... 13 4.3.1 Drums, Headers and Tubes (Water Side) ........................................ 14 4.3.2 Drums, Headers and Tubes (Gas Side) ........................................... 14 4.3.3 Superheater ................................................................................... 15 4.3.4 Economizer ................................................................................... 15 4.3.5 Refractories, Casing and Baffles ..................................................... 16 4.3.6 Water Columns .............................................................................. 17 4.3.7 Feedwater Regulator ...................................................................... 17 4.3.8 Soot Blowers ................................................................................. 17 4.3.9 Valves ........................................................................................... 18 4.3.10 Safety Valves ................................................................................. 18 4.3.11 Windbox ........................................................................................ 19 4.3.12 Oil Firing ....................................................................................... 19 4.3.13 Gas Firing ...................................................................................... 21 4.3.14 Ash Removal System ..................................................................... 21 4.3.15 Air Preheater ................................................................................. 21 4.3.16 Fans ............................................................................................... 22 4.3.17 Dampers ........................................................................................ 23 4.3.18 Operating Checks .......................................................................... 23 4.4 Maintenance Checks (Fire Tube Boilers) ........................................ 25 4.4.1 Combustion Chamber ..................................................................... 25 4.4.2 Tubes (Gas Side) ........................................................................... 25 4.4.3 Tubes and Shell (Water Side) ......................................................... 26 4.4.4 Operating Checks .......................................................................... 26 4.5 Periodic Maintenance Schedule ...................................................... 27 4.5.1 Daily Maintenance ......................................................................... 27 4.5.2 Weekly Maintenance ...................................................................... 29


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Page 4.5.3 Monthly Maintenance .................................................................... 30 4.5.4 Annual Maintenance ...................................................................... 31 4.6 Maintenance Guide ........................................................................ 32 4.6.1 Water Tube Boilers ........................................................................ 33 4.6.2 Fire Tube Boilers ........................................................................... 33 5. Special Boilers ............................................................................... 33


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STEAM BOILERS - PART 16: REQUIREMENTS FOR MAINTENANCE

1- SCOPE AND FIELD OF APPLICATION

This standard is concerned with the maintenance of steam boilers.

2- COMPLEMENTARY REFERENCES

2.1 SASO 1338/1997 “Steam Boilers - Part 8: General Safety Requirements”.

2.2 SASO 1339/1997 “Steam Boilers - Part 9: Approval of Inspection Body”.

2.3 SASO 1340/1997 “Steam Boilers - Part 10: Approval of Operators”.

2.4 SASO 1341/1997 “Steam Boilers - Part 15: Requirements for the Operation”.

2.5 SASO 694 to 700/1992 “Code of Practice for the Inspection and Testing of Steam and Hot Water Boilers - Part 1 to Part 7”.

2.6 SASO ...../..... “Steam Boilers - Part 14: Requirements for the Installation”.

3- DEFINITIONS

3.1 Boiler: An arrangement of vessels and interconnecting parts, wherein water is heated and steam is generated by the application of heat.

3.2 Approved Inspector: A person trained and qualified in accordance with the requirements of Saudi standards, employed by the inspection body and obtained approval by the authority (SASO) to carry out inspection of boilers.

3.3 Owner: The individual or organization which makes use of the boiler for its own benefit.

3.4 Maintenance organization: The organization or person carrying out and responsible for the maintenance.

3.5 Boiler Operator: A person who operates and controls a boiler or a section of the boiler with the authority of the owner. This person shall possess a boiler operator’s certificate issued by the boiler inspector.

3.6 Hydrostatic test: A strength and tightness test of a closed pressure vessel by water pressure.

3.7 Header: The piping which connects two or more boilers together. It may be either supply or return piping.


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3.8 Inspection opening: The opening in a pressure vessel of sufficient diameter to permit a vessel inspection.

3.9 Damper: A device for introducing a variable resistance for regulating the volumetric flow of gas or air.

3.10 Safety valve: An automatic pressure relieving device actuated by the static pressure upstream of the valve and characterized by full opening pop action.

3.11 Cock: A plug- or ball-type valve in which a 90o turn of the handle will move the valve to full open or closed position. Such cocks are designed so that they are open when the handle is parallel with the line of flow.

3.12 Drain valve: A valve connection at the lowest point of the pressure vessel body for the removal of all water.

3.13 Gauge glass: The transparent part of a water gauge assembly connected directly or through a water column to the boiler, below and above the water line, to indicate the water level in the boiler.

3.14 Fire tube: A tube in a boiler having water on the outside and carrying the products of combustion on the inside.

3.15 Competent person: A person who has through a combination of training, education and experience acquired knowledge and skills enabling that person to perform correctly a specified task.

3.16 Interlock: A device that makes the operation of an item of the boiler dependent on the fulfillment of predetermined conditions by another item of the boiler.

3.17 Management system: The manual, semi-automatic or fully automatic electric, pneumatic, hydraulic or computer control system used for surveillance, control, sequential operation and protection of pressure equipment or a specific section of the equipment.

3.18 Watertube boiler: A boiler in which the tubes contain water and steam, the heat being applied to the outside surface.

3.19 Firetube boiler: A boiler in which the tubes contain fire and products of combustion, surrounded by water and steam, the heat being applied to the inside surface.

3.20 Smoke box: An external compartment on a boiler to catch unburned products of combustion.

3.21 Steam trap: A device installed in steam piping which is designed to prohibit the passage of steam but it allows the passage of condensate and air.

3.22 Forced draft boiler: A boiler which operates with the furnace pressure higher than the atmospheric pressure.

3.23 Induced draft boiler: A boiler which operates with the furnace pressure less than the atmospheric pressure due to action of an induced draft fan.


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3.24 Induced draft fan: A fan exhausting hot gases from the heat absorbing equipment.

3.25 Forced draft fan: A fan supplying air under pressure to the fuel burning equipment.

4- REQUIREMENTS

4.1 General

4.1.1 It is the owner’s responsibility to ensure that the boiler and its settings, management system interlock, and energy and environmental equipment are maintained in a safe condition and not likely to present a hazard to workers and public. Poor maintenance can also result in unscheduled stoppages of boiler which will end up in production loss and an increase in the costs of the unit produced. This standard will assist in identifying the trouble spots and conditions that should be checked during regular maintenance stoppages and operations.

4.1.2 During maintenance, individual manufacturer’s instruction books shall be referred to for more details on the design, construction, controls and maintenance of that particular boiler.

4.1.3 The owner shall ensure that a maintenance program is established in accordance with this standard and adhered to for the boiler and all its auxiliaries.

4.1.4 Maintenance shall be carried out by an experienced and qualified boiler maintenance organization or personnel.

4.1.5 The maintenance organization shall obtain approval from approved inspecting body to operate as an approved maintenance organization.

4.1.6 The maintenance organization shall have the following as a minimum requirement for approval as a boiler maintenance and testing organization:

4.1.6.1 It shall have experienced staff and procedures to ensure that the appropriate maintenance will be carried out competently.

4.1.6.2 Have staff with at least 2 years experience in the field of maintenance and operation of steam boilers and boiler auxiliaries.

4.1.6.3 Maintenance personnel:

Maintenance personnel shall have the following qualification and experience:

4.1.6.3.1 Two (2) years maintenance experience and training with the type of pressure equipment systems to be maintained.

4.1.6.3.2 Be a graduate engineer in an appropriate discipline or be an appropriately qualified technician.


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4.1.6.3.3 Be able to read and interpret technical drawings.

4.1.6.3.4 Have other equivalent qualifications acceptable to authorized inspector.

4.1.7 Welding

4.1.7.1 No welding repairs to a boiler pressure part shall be initiated without the approval of the authorized inspector who should satisfy himself that the welding procedures and welders are qualified and approved by an authorized inspector. Any modification/alteration in the boiler designs shall be approved by the boiler manufacturer.

4.1.7.2 The welding repairs and alterations shall be made by an approved welder or authorized organization approved by the authorized inspector, provided that the alterations are within the scope of such authorization.

4.1.7.3 All welding repairs and alterations shall be documented and kept with the General Register maintained for each boiler as specified in the Saudi standard mentioned in item 2.1.

4.1.8 Information to assist maintenance

The ability to recognize symptoms of impending equipment failure and to identify the faulty part is an important task in preventing complete equipment failure without previous warning. The procedures mentioned below shall assist the operator in recognizing and identifying faulty equipment parts so that he can take necessary action to shutdown the boiler in advance and arrange for repair and maintenance.

4.1.8.1 Monitoring

4.1.8.1.1 The owner shall be responsible and ensure that programmed monitoring is carried out as appropriate to the design parameters and operating conditions.

4.1.8.1.2 Monitoring shall cover all operational parameters which provide necessary information for the assessment of current and long term safety and life of the boiler.

4.1.8.1.3 The signs of deterioration shall be noted when the equipment is in service and repairs shall be arranged with other pertinent data which will help in scheduling the next overhaul and estimating the required downtime.

4.1.8.1.4 The monitoring may include the following actions:

- Observation, recording and processing of operational data such as pressures, temperatures, temperature gradients, and cycles which can also be used for the calculation of assumed remaining life where the boiler is affected by creep fatigue.


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- Vibration monitoring.

- Visual observation and survey to detect progressive changes in configuration, changes in support, corrosion on external surfaces and general damage.

- Use of specialized measuring equipment such as corrosometers.

- Use of specialized metallurgical or non-destructive examination procedures.

4.1.8.2 Maintenance checks

The maintenance checks shall be designed to give a listing of those parts which are subject to wear, corrosion, erosion, etc., and are most likely to be the cause of equipment failure.

4.1.8.3 The operators shall look for any abnormal conditions of boiler during the normal performance of their duties to determine the physical condition of the boiler and to carry out the maintenance.

4.1.9 Maintenance programs

4.1.9.1 The maintenance of boiler shall be controlled by a planned program, and the components parts of any program will directly vary according to the quantity and complexity of the equipment.

4.1.9.2 The program shall consist of the following basic parts:

4.1.9.2.1 Inspection and overhaul procedures.

The information in this section can provide the base to prepare a set of inspection and overhaul procedures for a particular part.

A procedure can be designed for the following operation during partial or complete overhaul:

- Equipment in service prior to overhaul.

- Equipment out of service.

- Equipment in service following an overhaul.

- Partial overhauls are carried out for rotating or reciprocating equipment and shall consist of an inspection of parts which are subject to wear.

- A complete overhaul may be carried out to examine every possible cause of future equipment failure or to verify the capability of the equipment to perform its function.

- An inspection may also be made during normal operation to check performance.


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4.1.9.2.2 Overhaul scheduling:

- Every maintenance program shall include a comprehensive equipment overhaul schedule.

- The schedule shall be based upon such considerations as production requirements, equipment capacities, number of boiler available as standby, operating experience and equipment performance.

4.1.9.2.3 Equipment history:

- Equipment history can be used to spot those maintenance items requiring frequent attention and to assist in preparing or modifying the equipment overhaul schedule.

- The equipment history shall list the major parts repaired or replaced during an overhaul so that spare parts inventories can be reviewed.

4.1.9.2.4 Training

- Personnel training to recognize, identify and report the danger signals of impending equipment failure are very important in averting unscheduled shutdowns and failures.

- Any signals or indications of abnormal operations shall be recorded in the general register maintained with each boiler.

4.1.9.2.5 Equipment improvement

After a failure of equipment and during overhaul every effort shall be made to improve any inherent equipment defects by a change of material, lubrication, environment, temperature, pressure or any other means, in the interest of safety. Any modification or alteration shall be fully documented and approved by the authorized inspector.

4.1.10 Housekeeping of boiler area

The owner shall ensure that the boiler and its surrounding area are kept in a clean, safe and tidy condition including the following:

4.1.10.1 Removal of all excess equipment and materials from the area.

4.1.10.2 Removal of all substances and obstacles from stairways, platforms and access areas.

4.1.10.3 Removal or isolation of spillages of liquid and gaseous fuels, ash and dust.

4.1.10.4 Sufficient illumination to allow safe maintenance.


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4.2 Safety during maintenance

4.2.1 The owner shall be responsible for providing a clear set of safe working procedures for the prevention of hazardous incidents that could occur during maintenance.

4.2.2 The responsible person shall ensure that no person enters a boiler without an entry permit.

4.2.3 The entry permit shall not be issued until the following conditions are met:

4.2.3.1 The boiler space contains a safe oxygen level.

4.2.3.2 The boiler space is free from high temperature and it is acceptable for entry.

4.2.3.3 The boiler is depressurized, drained and decontaminated.

4.2.3.4 Have ventilation that provides an acceptable atmosphere for entry, which shall be maintained during maintenance.

4.2.3.5 Be isolated from all sources of pressure, dangerous materials, and from mechanical or electrical power.

4.2.3.6 Lockout and tag all equipment items with movable parts connected to the boiler and fuel system and place a sign at the operating controls indicating that a workman is inside the boiler.

4.2.3.7 A standby person is posted at the entry of the boiler watching from outside the boiler.

4.2.4 The entry permit shall include all precautions and instructions necessary for safe entry and execution of work.

4.2.5 All hot work, such as oxy-cutting, welding and grinding, shall be carried out in a safe manner to avoid risk of fire, explosion, collapse or other damage to equipment or persons. Suitable precautions such as fire extinguishers shall be provided near the place of hot work. Hot work permit shall be obtained before undertaking any of the above operations.

4.2.6 Suitable precautions shall be taken to discharge any static electricity generated during maintenance.

4.3 Maintenance checks

The maintenance checks indicated in this section are general in nature and these checks shall be used as a broad base from which to prepare thorough maintenance programme for each boiler. It is applicable to all types of boilers. All the information and observations made during these checks shall be noted and action shall be taken in accordance with the manufacturers recommendations and with the experienced and competent person’s observations. Wherever necessary maintenance or adjustment shall be carried out as soon as possible after the check or during the check.


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4.3.1 Drums, headers and tubes - (water side).

4.3.1.1 Check steam drums(s) for corrosion, scale, pitting, or other causes for metal reduction.

4.3.1.2 Clean inspection hole seats, resurface if necessary, and replace gaskets.

4.3.1.3 Check steam scrubber and dryer in steam drum (if applicable) for corrosion, deposits, erosion, cracks and to ensure security and tightness of joints.

4.3.1.4 Check condition of all chemical feed and blow-down lines inside pressure parts for plugging, security, leaks, and orientation.

4.3.1.5 Check for freedom of expansion for drums and headers.

4.3.1.6 Inspect tubes for corrosion, excessive deposits, flare cracking, and pitting.

4.3.1.7 Replace all handhole gaskets on headers. Inspect the surface of the handhole plates and stud threads.

4.3.1.8 Make a complete water side examination and check for scale buildup as necessary. Measure scale thickness by using commercially available gauges.

4.3.2 Drums, headers, and tubes - (gas side)

4.3.2.1 Check exterior of drums for signs of tube roll leakage, corrosion, fly ash erosion, or overheating.

4.3.2.2 Check condition of outside drum insulation and replace or repair as necessary.

4.3.2.3 Check drum seals for signs of air leakage.

4.3.2.4 Inspect drum supports for conditions and check expansion clearance.

4.3.2.5 Check all blowdown connections for expansion and flexibility of support. Inspect all piping and valves for leaks.

4.3.2.6 Visually check water wall tubes and fins (if applicable) for cracks.

4.3.2.7 Check exterior of all tubes for corrosion, deflected surfaces, erosion, blisters, swelling, and sagging.

4.3.2.8 Inspect boiler tubes at soot blower for signs of steam impingement.

4.3.2.9 Check header seals for signs of air leakage.

4.3.2.10 Examine exterior of headers for corrosion, erosion, thermal cracking, and condition of insulation.

4.3.3 Superheater

4.3.3.1 Inspect superheater header and tubes for corrosion, erosion, external deposit, and overheating.


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4.3.3.2 Check for steam impingement on tubes at soot blower location.

4.3.3.3 Check superheater header and tubes for complete freedom of expansion.

4.3.3.4 Check for cleanliness of superheater and ensure its venting and drainage.

4.3.3.5 Examine superheater header and tube supports for security.

4.3.4 Economizer

4.3.4.1 Check interior of tubes and headers where possible for corrosion, oxygen pitting, and scale.

4.3.4.2 Check exterior of tubes and headers for corrosion, erosion, and deposits. Check particularly at soot blower locations for impingement and leakage.

4.3.4.3 Check for cleanliness and security of vent and drain connections and valves.

4.3.4.4 Check exterior of economizer casing for leaks and tightness of access doors.

4.3.4.5 Check condition of casing insulation.

4.3.4.6 Overhaul all water valves. Check for leaks.

4.3.4.7 Check condition of supporting steel.

4.3.5 Refractories, casing, and baffles

4.3.5.1 Check furnace tile, brick, and castable refractories for loose, spalled, or missing pieces.

4.3.5.2 Examine soot and ash hoppers for eroded refractories and condition of seals.

4.3.5.3 Check particularly for deterioration of burner tile and signs of flame impingement.

4.3.5.4 Inspect condition of supporting steelwork where visible.

4.3.5.5 Visually check exterior of burner casing for bent, broken, or bowed sheets. Patch or repair as necessary.

4.3.5.6 Check all access doors, lancing doors, etc., for tightness. Renew gaskets as required.

4.3.5.7 Test unit for air leaks with a suitable method consistent with design. This could be done by pressurizing and using a sonic detector or a smoke detector, or by feeling for air leaks.

4.3.5.8 Check condition of all baffle gasket and caulking with particular attention to signs of leakage and check for security of supports.

4.3.6 Water columns

4.3.6.1 Check gauge glasses for leaks, cleanliness, and visibility.


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4.3.6.2 Check illuminators, reflectors, and mirrors for cleanliness and breakage.

4.3.6.3 Check operation and condition of gauge cocks and valves. Inspect chains and pulleys if used. Repair or replace as necessary.

4.3.6.4 Ensure that water column is free to expand with boiler.

4.3.6.5 Check water column piping to drums for leaks, internal deposits, and missing insulation.

4.3.6.6 Check condition of high and low water alarms and any other problems.

4.3.7 Feedwater regulator

4.3.7.1 Examine valve externally for leaks, operability, and cleanliness. Do not dismantle if operation has been satisfactory. Check connecting lines and mechanisms for proper function.

4.3.7.2 If overhaul is necessary, consult inspector before proceeding.

4.3.8 Soot blowers

4.3.8.1 Check alignment of all soot blower hangers and check tightness of hanger bolts.

4.3.8.2 Check soot blower elements for distortion, worn hanger bearings, tube rubbing, condition of element nozzles, element breakage or cracking, freedom of movement, effective lubrication, and correct adjustment.

4.3.8.3 Check condition of wall boxes. They should be sealed and secure.

4.3.8.4 Check condition of moving parts, valves, and packing in soot blower head. Replace packing.

4.3.8.5 Check position of elements for signs of steam impingement on tubes.

4.3.8.6 Check each soot blower for correct blowing arc and direction of rotation.

4.3.8.7 Pack the swivel tube gland and check swivel tubes for erosion and corrosion.

4.3.8.8 Check gooseneck fittings for erosion and corrosion.

4.3.8.9 Check steam supply piping and valves for evidence of leaks.

4.3.8.10 Check condition of drain piping and valves. Ensure that supply piping slopes away from soot blower head.

4.3.8.11 Check for evidence of overheating.

4.3.9 Valves

Check condition and operation of all feedwater, blowdown, drain, and other miscellaneous valves. Replace parts as necessary and repack.


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4.3.10 Safety valves

If a safety valve was found to malfunction during the pre-shutdown test, the following operations shall be conducted by qualified and experienced maintenance personnel.

4.3.10.1 Check condition of valve nozzle and disk seats. Lap seats, if required, in accordance with manufacturer’s instructions.

4.3.10.2 Check condition of valve internal parts for corrosion, galling, seizing and wear. Recondition or replace, if necessary.

4.3.10.3 Check for pitting, cracking, resiliency, and squareness of the coil ends of the valve spring.

4.3.10.4 Check spindle for straightness and adjusting ring threads for freedom of movement.

4.3.10.5 Check discharge and drain piping for security, clear of all obstructions inside, and allowance for boiler expansion.

4.3.10.6 Test operation of valves by steam pressure (on the boiler if necessary) and adjust them to open and close at the proper pressures. Record set pressures and blowdown.

4.3.11 Windbox

4.3.11.1 Check air dampers and vanes in windbox for corrosion and erosion. Check damper and vane operating mechanism.

4.3.11.2 Check windbox insulation and repair as necessary.

4.3.11.3 Check condition and operation of all windbox access doors, peep holes and cover plates. Check for air leaks. Look for cracked sight glass in furnaces and burners and replace them.

4.3.12 Oil firing

4.3.12.1 Fuel oil pumps

4.3.12.1.1 Check condition of gear-type pumps. Check for:

- excessive clearances

- excessive backlash

- worn bearings

- leakage

4.3.12.1.2 Check condition of steam driven reciprocating pumps.

Check for:


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- wear in steam cylinder and piston.

- wear in oil cylinder and piston.

- condition of oil and steam cylinder piston rings.

- setting, operating, and wear of steam valves.

- condition and seating of oil valves.

- leaks from bearing and check the surfaces of piston rods for any defects.

- condition of steam strainers.

- leaks at all connections.

4.3.12.2 Fuel oil heaters

4.3.12.2.1 Check tube bundle and clean off deposits on oil side.

4.3.12.2.2 Inspect steam and oil side for corrosion and erosion.

4.3.12.2.3 Check freedom of vents and drains.

4.3.12.2.4 Check condition of insulation and repair as necessary.

4.3.12.2.5 Check for tubesheet and tube leaks.

4.3.12.2.6 Check condition, operation, and setting of relief valves.

4.3.12.3 Burners, valves and piping

4.3.12.3.1 Check setting and operation of pump discharge pressure regulators.

4.3.12.3.2 Check setting and operation of pressure relief valves on pump discharge.

4.3.12.3.3 Check setting and operation of steam pressure reducing valve on oil heater.

4.3.12.3.4 Clean and check oil suction strainer.

4.3.12.3.5 Check and calibrate pressure gauges and thermometers.

4.3.12.3.6 Clean and check steam strainer.

4.3.12.3.7 Check operation of oil heater condensate steam trap.

4.3.12.3.8 Recondition all shutoff and adjusting valves as necessary. Perform leak check on shutoff valves after reconditioning.

4.3.12.3.9 Clean and inspect oil burners. Check for leaks, erosion, and carbonization of burner nozzle, especially at the joint between gun and permanent piping.

4.3.12.3.10 Check for leaks at all connections.

4.3.13 Gas firing

4.3.13.1 Check condition of gas nozzles for erosion, burning, or plugging.

4.3.13.2 Check operation of air control damper mechanism.

4.3.13.3 Check setting and operation of pressure regulating valve.


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4.3.13.4 Check all piping and valves for leaks.

4.3.13.5 Check safety shutoff valves for leakage; repair as necessary.

4.3.13.6 Check condition, operations, setting of relief valve on the gas line.

4.3.14 Ash removal system

During an overhaul, all parts of any particular system shall be thoroughly inspected for the following conditions:

4.3.14.1 wear, erosion, corrosion, and leaks

4.3.14.2 effective operation of sluicing mechanisms

4.3.14.3 condition of ash pits and sumps including refractory

4.3.14.4 operation of vacuum systems and centrifugal collectors

4.3.14.5 wear in transport piping, particularly at bends and elbows

4.3.14.6 condition of ash pumps

4.3.15 Air preheater

4.3.15.1 Tubular or plate type

4.3.15.1.1 Check gas side for plugging and buildup at inlet and for corrosion and erosion at outlet.

4.3.15.1.2 Check air side for corrosion and leaks.

4.3.15.1.3 Use water washing to clean the deposits and subsequently dry the air heater. If deposits are hard, then resort to alkali rinse. Dispose wash water after suitable neutralization.

4.3.15.2 Regenerative type

4.3.15.2.1 Check cold end section of heater surface for wear, plugging, and corrosion,

4.3.15.2.2 Check condition of radial and circumferential seals on both hot and cold ends.

4.3.15.2.3 Check condition of gear drive.

4.3.15.2.4 Check operation and condition of soot blower (if fitted).

4.3.15.2.5 Check effectiveness of bearing and lubricating system (if provided) cooling.

4.3.15.2.6 Use water washing to clean the deposits and subsequently dry the air heater. If deposits are hard, then resort to alkali rinse. Dispose wash water after suitable neutralization.

4.3.15.2.7 Check condition and operation of air supply motor.


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4.3.16 Fans

4.3.16.1 Forced draft and primary air fans

4.3.16.1.1 Check fan housing and rotor for corrosion, erosion, and signs of housing leaks. Check impeller for proper fixing, strong welds or cracks and deformations. Check casing for loose bolting, rivetting or welding.

4.3.16.1.2 Check clearance between rotor and fan housing.

4.3.16.1.3 Check bearings for wear, clearance, lubrication, and cooling.

4.3.16.1.4 Check coupling alignment at operating temperature.

4.3.16.1.5 Check lubrication system (if provided).

4.3.16.1.6 Check balancing of fan motor.

4.3.16.2 Induced draft fans

4.3.16.2.1 Check fan housing and housing liners for erosion, corrosion, fly-ash deposit, and housing leakage.

4.3.16.2.2 Check fan rotor and liners for erosion, corrosion, fly-ash deposit, and weak of rivets and welds.

4.3.16.2.3 Check clearance between rotor and fan housing.

4.3.16.2.4 Check condition of shaft seals.

4.3.16.2.5 Check bearings for wear, lubrication, and cooling.

4.3.16.2.6 Check coupling alignment at operating temperature.

4.3.16.2.7 Check lubrication system (if provided).

4.3.16.2.8 Check balancing of fan motor.

4.3.17 Dampers

4.3.17.1 Check to ensure that linkage arms are secure on the blade shafts.

4.3.17.2 Check to see that the blade(s) follow through the open to closed position as indicated on the linkage arm sector plate, or other external indicator.

4.3.17.3 Check for indications of inservice binding, and ensure that clearances are adequate for expansion.

4.3.17.4 Check to see that minimum stops, where required, are in place.

4.3.17.5 Check to see that sealing strips on tight closure dampers are not deteriorated or worn.

4.3.17.6 Check to see that damper blades are clean, and the metal is not corroded or eroded.

4.3.17.7 Check to see that bearings are lubricated.

4.3.17.8 Check for wear of internal bearings or link joints.

4.3.17.9 Check to see that flues and ducts are free of debris.


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4.3.17.10 With remote controlled dampers, check to see that the drive strokes through the full range without binding.

4.3.17.11 As applicable, during purging at startup and at shutdown of a unit, check to see that the strokes of the induced and forced draft dampers are operating properly.

4.3.18 Operating checks

4.3.18.1 Leakage

4.3.18.1.1 Check for any flue gas, steam, or water leaks.

4.3.18.1.2 Check for steam leaks at superheater headers and tube joints.

4.3.18.1.3 Check for air leaks around doors, seals, and furnace.

4.3.18.2 Refractories

4.3.18.2.1 Check condition of burner throat refractories.

4.3.18.2.2 Check condition of ash pit refractories (if applicable).

4.3.18.2.3 Check for slag buildup on refractories.

4.3.18.2.4 Check for missing insulation on headers and drum.

4.3.18.3 Burners

4.3.18.3.1 Check for burner wear by noting flame shape and completeness of combustion.

4.3.18.3.2 Check ease of operation of burner vanes. This will indicate burner operating condition.

4.3.18.4 Drums

4.3.18.4.1 Check the steam quality for impurities to indicate the condition of steam scrubbers and separators.

4.3.18.4.2 Check for noises in drums. This may be caused by loose connections of drum internal piping.

4.3.18.5 Soot blowers

4.3.18.5.1 Check steam pressure to soot blowers and blowing pressure.

4.3.18.5.2 Check for a decrease in steam pressure at soot blower inlet during operation. This will indicate a breakage of the element or missing nozzles.

4.3.18.5.3 Check pressure in supply piping with main supply valve out. This will indicate leaking of shutoff valve.

4.3.18.6 Economizer and air preheater

4.3.18.6.1 Check for a variation in temperature differences over both units at constant load. This will indicate deposits or bypassing air preheater.


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4.3.18.7 Pressure variations

4.3.18.7.1 Check for an increase in pressure difference over any part of the system at constant load, which indicate deposits or buildup.

4.3.18.7.2 Check for a decrease in pressure difference over any part of the system at constant load, indicating a misplaced or bypassed baffle.

4.3.18.8 Furnace and casing

4.3.18.8.1 Check the extent expansion and contraction of pressure parts during startup and shutdown.

4.3.18.8.2 Check the hangers on top of boiler, on headers, ducts and lines and ensure that they are always in tension. Looseness will indicate an obstruction to free expansion and contraction.

4.4 Maintenance checks (fire tube boilers)

These maintenance checks are applicable to fire tube boilers in addition to the checks mentioned in item 4.3.

4.4.1 Combustion chamber

4.4.1.1 Check the refractory and brickwork for burning, spalling of the edges, erosion, and deterioration. Repair or replace as necessary.

4.4.1.2 Check for bending and sagging of metal parts of furnace.

4.4.1.3 Check for leaks around the seal between the combustion chamber and front and rear tubesheets.

4.4.2 Tubes (Gas side)

4.4.2.1 Clean and inspect tubes on gas side. Note the amount of soot deposit as a check of burner operation.

4.4.2.2 Check for signs of overheating in initial tube passes.

4.4.2.3 Check for signs of tube leaks.

4.4.2.4 Check gas distribution partitions and connections and gaskets on front and rear heads for signs of gas bypassing or leakage.

4.4.2.5 Clean out and inspect refractories in gas side. Check for burnt and spalled refractory materials which could block tube passes and also cause hot spots on water side.

4.4.2.6 Check for signs of water leaks around staybolt and braces.

4.4.2.7 Check for cracks and signs of water leakage at tube ends.


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4.4.3 Tubes and Shell (Water Side)

4.4.3.1 Check for scale and corrosion on tubes, tubesheets, staybolts, and braces.

4.4.3.2 Clean water side and take samples of excessive scaling for analysis and determination of further treatment required.

4.4.3.3 Check for bent, or warped tubes or tubesheets due to overheating or hot spots.

4.4.4 Operating Checks

4.4.4.1 Check pressure difference over gas passes and compare with previous readings at similar loads to determine cleanliness.

4.4.4.2 Check for sagging or “bagging” of tubes on horizontal return tubular (H.R.T.) boilers.

4.4.4.3 Check exit gas temperature and compare with steam temperature at normal loading to determine the extent of any fouling of heat exchange surface.

4.4.4.4 Check for hot spots in refractories, flame conditons, and general conditions as visible through front and rear peep holes.

4.4.4.5 Check for any visible water leaks from boiler drum.

4.4.4.6 Whenever possible, check the operation of safety features on combustion controls and water level.

4.5 Periodic maintenance schedule

The owner shall be responsible for the periodic checking and maintenance of the boiler to ensure its safe and reliable operation. The maintenance check schedule shall be in accordance with this standard as a minimum and also in accordance with the service manual of each boiler type.

4.5.1 Daily maintenance

The following shall be carried out:

4.5.1.1 Observe operating pressures, water level, and general conditions. Determine cause of any unusual noise or conditions and correct.

4.5.1.2 Blowdown the water gauge glass.

4.5.1.3 Check operation of water level equipment (low water device).

4.5.1.4 Check start-up and shutdown for correct sequence (automatic boilers).

4.5.1.5 Check the operation of flame detection system for automatic shutdown.

4.5.1.6 Examine all glands, flanges, and connections to ensure that there is no substantial leak.

4.5.1.7 Examine all locks and seals to ensure that no tampering has occured.


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4.5.1.8 Blowing down of water level controls

4.5.1.8.1 Steam and water columns and control chambers should be blowdown at least once every eight hours and check that safety cut outs are working properly. Isolation of the control chambers caused by boiler operatives closing and leaving closed, either steam or water isolating valves or both after closing the drain valve, has been the cause of many boiler explosions resulting from overheating caused by low water. When using the main blowdown valve (drain) the operator must not under any circumstances leave the valve unattended.

4.5.1.8.2 Operation and maintenance of blowdown (drain) valve

Before operating blowdown valve, check that the pipework and pit cover are secure and that no one is working in the adjacent pit or boiler plant.

Always open the valve slowly to allow gradually warming through of the pipework and pit. After a few seconds open valve fully. As soon as low water and extra low water controls have been activated the valve shall be closed and the key removed. All valves shall be closed firmly by hand. A leaking valve will not make a better seal if it is forced. Excessive force will only damage the valve.

4.5.1.9 Burners

Carry out maintenance on burners as follows:

4.5.1.9.1 Inspect atomizer and keep clean. Do not use metal scrapers and do not damage the edge of atomizer. If edge of atomizer is damaged replace it. Use a paraffin rag for cleaning.

4.5.1.9.2 Keep furnace and burner equipment clean, repair any leaky joints without delay and clean up any pools of oil.

4.5.1.9.3 Check CO2 and gas exit temperature to ensure that burner setting have not altered.

4.5.1.10 Keep all flanged connections tight. Do not operate a leaky burner or piping system.

4.5.2 Weekly maintenance

In addition to the daily maintenance the following shall be carried out weekly:

4.5.2.1 Test low water fuel cut-off and/or water feeder.

4.5.2.2 Blowdown boiler to maintain chemical concentrate at the required level.

4.5.2.3 Test water column or gauge glass.

4.5.2.4 Observe condition of flame; correct if flame is smoky or if burner starts with a puff.

4.5.2.5 Check fuel supply.

4.5.2.6 Observe operation of condensate or vacuum pump.


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4.5.2.7 Water level controls

With burner firing test water level controls as follows:

4.5.2.7.1 With boiler attendant standing by, switch feed pump off and allow water level to fall by evaporation.

4.5.2.7.2 At a level indicated by the manufacturer when modulating water level controls are fitted, the lockout light will become illuminated and the alarm will operate.

4.5.2.7.3 Check that all alarm signals operate and that boiler stops.

4.5.2.7.4 Put pump switch to “auto” and when pump stops, operate spring-loaded switch to reset position and the burner will restart.

4.5.2.7.5 Check feed pump filter.

4.5.2.8 Burner maintenance

4.5.2.8.1 Keep the burner and its associated equipment in clean condition.

4.5.2.8.2 Keep the air casing passage clean and free from obstruction.

4.5.3 Monthly maintenance

In addition to the weekly maintenance a monthly maintenance shall be carried out as follows:

4.5.3.1 Check the operation of safety valves (lever test).

4.5.3.2 Check the flame detection devices.

4.5.3.3 Check the operation of limit controls.

4.5.3.4 Operate sludge blowdown where required.

4.5.3.5 Check boiler room floor drains for proper functioning.

4.5.3.6 Follow a regular schedule for cleaning flues, furnace, and boiler tubes, chimneys, etc. as necessary for the particular installation.

4.5.3.7 Inspect fuel supply systems in boiler room area.

4.5.3.8 Check the condition of heating surfaces.

4.5.3.9 Check combustion air supply opening to ensure that it is not closed or stopped up.

4.5.3.10 Check water level devices, disassemble, check chambers and valves and check operation.

4.5.3.11 Check the operation of fan and airflow interlocks.

4.5.3.12 Check fuel safety shut-off valves for leakage.


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4.5.3.13 Check the operation of fire interlock.

4.5.3.14 Check the operation of steam pressure interlock.

4.5.3.15 Check fuel pressure and temperature interlocks of oil fired boilers.

4.5.3.16 Check main gas filter and high and low fuel pressure interlocks of gas fired boilers.

4.5.3.17 Clean and check fuel filters.

4.5.3.18 Clean and check water filters.

4.5.3.19 Check the quality of feedwater and boiler water.

4.5.3.20 Check the feedwater pump for operation pressure and wear.

4.5.3.21 Keep strainers clean following a regular schedule. Shut-off valves shall be installed at strainers so that lines will not drain when strainers are opened.

4.5.3.22 Clean strainer baskets with kerosene for best results. Replace strainer baskets which are damaged in any way.

4.5.4 Annual maintenance

In addition to the monthly maintenance the following annual maintenance shall be carried out:

4.5.4.1 Internal and external inspection for scale, corrosion, and defects after thorough cleaning. The cleaning shall encompass the following:

4.5.4.1.1 Water side cleaning

The removal of heavy, loose or abnormal scale.

4.5.4.1.2 Fire side cleaning

The removal of dust, clinker or other coatings or deposits.

4.5.4.1.3 Drum

The insulation shall be removed from selected representative areas at planned intervals to enable the external surfaces to be inspected for defects. Internal parts shall be removed where necessary to permit cleaning and access.

4.5.4.1.4 Auxiliaries

The pressure parts such as water outlets, feedwater heaters, and blowdown vessels shall be cleaned as necessary.

4.5.4.2 Carry out burner maintenance.

4.5.4.3 Remove fan case cover and fan on oil burner at least once a year and clean out dust from all parts.

4.5.4.4 Carry out maintenance of condensate or vacuum return equipment.

4.5.4.5 Carry out maintenance of all combustion control equipment.


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4.5.4.6 Carry out combustion and draft tests.

4.5.4.7 Carry out safety valve maintenance and its operation test.

4.5.4.8 Inspect gas piping for proper support and tightness.

4.5.4.9 Inspect boiler room ventilation louvers and intake.

4.5.4.10 Check electric equipment and wiring.

4.5.4.11 Check all measuring instruments for proper functioning.

4.5.4.12 Clean and flush out pump reservoir at least once a year. This is done by removing thermometer and bottom drain plug and squirting in kerosene or flushing oil with a pressure gun or pump.

4.5.4.13 After performing the annual maintenance, each boiler shall be inspected and tested by an authorized inspector.

4.6 Maintenance guide

4.6.1 Water tube boilers

The minimum operating checks relating to maintenance for water tube boilers is given in appendix (A).

4.6.2 Fire tube boilers

4.6.2.1 The minimum maintenance checks for fire tube boilers is given in appendix (B).

4.6.2.2 The minimum operating checks relating to maintenance for fire tube boilers is given in appendix (C).

5. SPECIAL BOILERS

For boilers with capacity more than 3 tons or special purpose boilers shall follow the manufacturers recommendations in addition to the requirements mentioned above.


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APPENDIX (A)

WATER TUBE BOILERS OPERATING CHECKLIST RELATING TO MAINTENANCE

____________________________________________________________

Checked _________________

A-1 Leakage

Flue gas, steam, or water leaks ......................................................... ___________

Steam leaks at superheater headers and tube joints ........................... ___________

Air leaks around doors, seals, furnace, etc......................................... ___________

A-2 Refractories

Condition of burner throat refractories............................................... ___________

Condition of ash pit refractories (if applicable).................................. ___________

Slag buildup on refractories............................................................... ___________

Missing insulation on headers and drum............................................ ___________

A-3 Burners

Burner wear; note flame shape and completeness of combustion.................................................................................... ___________

Ease of operation of burner vanes indicating burner mechanism condition..................................................................... ___________

Cleanliness and no damage to sight glass in burner observation ports and peep holes in furance...................................................... ____________

A-4 Superheater Tubes

Change in pressure difference through the superheater, indicating internal condition of the tubes....................................................... ____________

A-5 Drums

Steam quality indicating the condition of steam scrubbers and

separators...................................................................................... ____________

Noise in drums which may be caused by loose connections

of drum internal piping................................................................. ____________


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Checked _________________

A-6 Soot Blowers

Steam pressure to soot blowers and blowing pressure......................... ____________ Decrease in steam pressure at soot blower inlet during operation indicating a breakage of the element or missing nozzles............................................................................. ____________

Pressure in supply piping with main supply valve out indicating leaking of shut-off valve................................................ ____________

A-7 Economizer and Air Preheater

Variation in temperature differences over both units at constant load indicating deposits or bypassing............................... ____________

A-8 Pressure Variations

Increase in pressure difference over any part of the system at constant load indicating deposits or build-up................................. ____________

Decrease in pressure difference over any part of the system at constant load indicating a misplaced or bypassed components....... ____________

A-9 Furnace and Casing

Extent of expansion and contraction of pressure parts during start-up and shut-down....................................................... ____________

Header support hangers are always in tension; looseness indicates an obstruction to free expansion and contraction.................................................................................... ____________

A-10 Fans

Forced draft and induced draft fans: Bearing temperatures of fan and motor...................................................................................... ____________

Vibration and abnormal sound........................................................... ____________ Oil leak, colour, flow......................................................................... ____________


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APPENDIX (B)

FIRE TUBE BOILERS MAINTENANCE CHECKLIST

____________________________________________________________ Checked _________________

B-1 Combustion Chamber

Refractories and brickwork for burning, spalling, erosion, and deterioration; repair or replace as necessary.............................. ___________

Bending and sagging of metal parts of chamber or grate.................... ___________

Leaks around the seal between the combustion chamber and front and rear tube sheets........................................................ ____________

B-2 Tubes Gas Side

Clean and inspect tubes on gas side; note the amount of soot deposit as an indication of burner operation............................ ___________

Signs of overheating in initial tube passes.......................................... ___________

Signs of tube leaks............................................................................. ___________

Flanges and gaskets on front and rear heads, and gas distribution partitions, for signs of gas leakage.............................. ___________

Clean out and inspect refractories in gas side of boiler heads; check for burnt and spalled refractories in tube passes which could cause hot spots on water side ............................................... ____________

Signs of water leaks around staybolt and braces ................................ ____________

Cracks and signs of water leakage at belled or rolled tube ends............................................................................................... ____________

B-3 Tubes and Shell Water Side

Scale and corrosion on tubes.............................................................. ____________

Scale and corrosion on tube sheets..................................................... ____________

Scale and corrosion on staybolts and braces....................................... ____________

Clean water side and take samples of excessive scaling for analysis and further treatment................................................. ____________

Bent, sagging, or warped tubes or tube sheets due to overheating or hot spots................................................................ ____________

________________________________________________________________________


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APPENDIX (C)

FIRE TUBE BOILERS OPERATING CHECKLIST RELATING TO MAINTENANCE

____________________________________________________________

Checked _________________

Maintenance...................................................................................... ___________

Pressure difference over gas passes; compare with previous readings at similar loads to determine cleanliness.......................... ___________

Sagging or “bagging” of tubes above combustion chamber of H.R.T. boilers................................................................................ ___________

Exit gas temperature; compare with steam temperature at normal loading to determine the extent of any fouling of heat exchange surface................................................................ ___________

Conditions of hot spots and the effect of flame on refractories and general conditions as visible through front and rear peep holes.............................................................................................. ___________

Any visible water leaks from boiler drum.......................................... ____________

Whenever possible, check the safety features on combustion controls and water level................................................................. ____________


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REFERENCES: Main Reference: - ASME - Boiler and Pressure Vessel Code - 1995. Section VII - “Recommended Guidelines for the Care of Power Boilers”. Other References: - Australian Standard AS 3873 - 1991 “Boilers and Pressure Vessels - Operation and Maintenance”. - ASME - Boiler and Pressure Vessel Code - 1995 Section VI - “Recommended Rules for the Care and Operation of Heating Boilers”.


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The preliminary draft of this standard has been developed by the work team composed of: Name Agency 1. Abdul-Hamid Ibrahim Jomaa College of Engineering - King Saud

University 2. Abdul-Aziz M. Al Goblon Al-Saghyir Steam Boilers Factor The draft standard was studied and the comments received thereon from concerned bodies discussed. It has been adopted, in its present form, by the following members of Technical Committee No. (2) “Pressure Vessels and Steam Boilers”. Name Agency 1. Abdullah Abdul Rahman Al-Azzaz Saline Water Conversion Corporation 2. Abdul-Hamid Ibrahim Jomaa College of Engineering - King Saud

University 3. Ali Abdul-Aziz Al-Azizi Saudi Consulting House 4. Salama Salem Al-Enazi Saudi Aramco 5. Abdul-Aziz M. Al Goblon Al-Saghyir Steam Boilers Factor 6. Khaled Rafiq Asfar College of Engineering - King Saud

University 7. Saleh Buwtey Rashed Al Buwtey Al Babtain Steam Boilers Factory 8. Farid Ahmed Younis Saudi Arabian Standards Organization 9. Mohamed Maha Thevan Saudi Arabian Standards Organization

SASO 1585 STEAM BOILERS - PART 16: REQUIREMENTS FOR ...zb.guaihou.com/stdpool/SASO 1585-1999 Steam Boliers... · 4.1.9.1 The maintenance of boiler shall be controlled by a planned

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