ANDERSON The Safety Selector Valve is designed ... · PDF fileAnderson Greenwood Safety Selector Valve ... SSV 1.50% 0.86% 1.42% 1.37% 1.31% ... Anderson Greenwood Series 400 pilot
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Features• Provides a safe, efficient method of
switching from an active pressure reliefdevice to a standby, maintaining systemoverpressure protection regardless ofSafety Selector Valve position.
• Provides high Cv values, resulting in lessthan 3% pressure drop to the active PRVinlet, when used with the largest APIorifice available in a given valve size, inaccordance with the recommendations ofAPI RP520 Part II and ASME Section VIII,Division 1, Appendix M, thereby greatlyreducing the possibility of destructivechatter of the PRV.
• Requires only one minimally sizedpenetration into the vessel or pipe, reducing costs.
• Greatly reduces field installation costsand space requirements throughpreassembled and compact design.
• Provides process isolation of standbypressure relief device.
• Allows pressure relief device maintenancewithout process shutdown.
• A bleed valve is provided under eachsafety relief device as an effective andsafe means of venting entrapped processunder an isolated pressure relief valveprior to removal for maintenance.
• Bright red indicator for positive indicationof active pressure relief device.
• Foolproof provisions for dual padlocking ineither pressure relief valve position, inaccordance with the recommendations ofASME Section VIII.
• Packing design has been tested to ASTME427, Method A halogen leak test,reducing probability of fugitive emissions.
• No seat lapping required for maintenance.Only recommended spare parts are softgoods which reduces cost of ownership.
• Meets standard temperature applicationsfrom cryogenic to +800°F [427°C].
• Offers materials of constructioncompatible with pressure relief devices.Duplex and 6MO material available.
• Provides reduced number of leak points toatmosphere, reducing probability offugitive emissions.
• Isolates a standby pressure relief valve inaccordance with joint recommendation ofAPI Subcommittee on Pressure RelievingSystems and Subcommittee on RefineryInspection.
• Type approval by Det Norske Veritas(DNV).
• Manufactured by an ISO 9001 certifiedfacility.
• Simplicity of operation with built-in seatequalization and no special toolsminimizes total time to operate valve.
Recommended SpecificationsChangeover device inlet connection is to bethe same size and rating as the pressurerelief valve inlets.
• Pressure drop through the changeoverdevice’s active side cannot exceed 3%with pressure relief valve fully open.
• Changeover device is to have externalindicator, showing which side is active.
• Provisions for double padlocking in either position are required.
• A valve bleed port must be located under each pressure relief valveconnection for pressure venting under the inactive pressure relief valve.
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
The Safety Selector Valve is designed specifically tofunction as an effective ‘switchover’ device.ANDERSON
GREENWOOD
Anderson Greenwood is either a trademark or registered trademark of Tyco International Services AGor its affiliates in the United States and/or other countries. All other brand names, product names, ortrademarks belong to their respective holders.
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
Section I Steam ServiceSafety Selector Valves can be utilized forcertain Section I Boiler applications.
Per ASME Section I Boiler and PressureVessel Code Case 2254, a switchover valvesuch as the Safety Selector Valve can beinstalled to provide a back-up safety valve forboilers with a maximum allowable workingpressure (MAWP) of 800 psig or less.
The code case requires that the followingcriteria be met by the switchover device:
The Safety Selector Valve will provide thehighest flow efficiency (Cv) of any otherswitchover device in the same nominal pipesize. These Cv values allow the SafetySelector Valve to be used with mostmanufacturers’ flanged Section I Boiler valvesand meet the code case requirements. Pleaseprovide us with the model number and setpressure of the safety valves to be used toinsure complete compliance with the codecase.
Operation
Dual Pressure Relief DeviceSystemsAnderson Greenwood developed the SafetySelector Valve in response to the growingdemand for cost-effective, dual pressure reliefvalve and/or rupture disc installations intoday’s process industries. The SafetySelector Valve is designed specifically tofunction as an effective ‘switchover’ devicethat permits routine or emergency servicingof redundant pressure relief devices with noprocess interruption, thus providingcontinuous system overpressure protection.Until recently, bulky and expensive pipingfabrications or total shutdown were the onlymethods for safely servicing the pressurerelief devices. These systems required eithertwo separate vessel penetrations withmechanically linked block valves or a 3-wayblock valve that commonly resulted in highinlet pressure loss, excessive turbulence tothe active pressure relief device and multipleleak points. The Anderson Greenwood SafetySelector Valve solves these problems. It iseasy to install, requiring only one vesselpenetration in the same size as the pressurerelief valve inlet. The unique design providesless than 3% pressure drop to the activepressure relief valve inlet when used with thelargest API orifice available in a given valvesize, in accordance with API RP520, Part IIand ASME Section VIII guidelines.
Interlocking BlockValve with Two Vessel
Penetrations
3-Way Block Valve with Pipe Elbows
(see Pressure Drop Comparison Below)
Interlocking BlockValve with Pipe Tee
and Elbows
Traditional Dual Pressure Relief Device Systems
Using API Standard 526 direct acting spring loaded valves, the comparative pressure dropthrough the Safety Selector Valve versus the same size 3-way ball valve is as follows:
2” 3” 4” 6” 8”2J3 3L4 4P6 6R8 8T10
SSV 1.50% 0.86% 1.42% 1.37% 1.31%
3-Way Ball 6.36% 5.65% 9.30% 10.6% 8.69%
Liquid/Two Phase ServiceSafety selector valves can be used inGas/Vapor, Steam, or Liquid service. Safetyselector valves can also be used in two phaseservice. The picture on the left is of anAnderson Greenwood Series 400 pilot valverelieving on liquid only. The picture on theright shows the same valve transitioning totwo phase flow as gas is becoming entrainedin the relief stream.
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
Notes1. Teflon® is a registered trademark of the E.I.
duPont de Nemours Company.
2. GRAFOIL® is a registered trademark ofUCAR Carbon.
The Anderson Greenwood Safety SelectorValve body houses a uniquely designedswitching mechanism. The internal rotorsmoothly diverts flow to either pressurerelief device. Either direct spring operatedvalves, pilot operated valves or rupturediscs may be used. The inactive device istotally isolated by external adjustment(Figures 1 and 5). To begin switchover, thepadlocks or seals are removed, the lock
hasp is opened, and the retractionbushing is rotated to its stop (Figure 2).This lowers the isolation disc from nozzleunder the standby valve and temporarily‘floats’ it in the main valve cavity. The indexshaft is then rotated 180 degrees to thealternate channel (Figures 3 and 4). Theretraction bushing is then raised, securelyseating the isolation disc beneath thevalve to be taken out of service (Figure 5).
A red pointer indicates which device is inservice and double padlocking provisionsallow the Safety Selector Valve to belocked in either position. The padlocks orcar seals can only be installed with theinternals in the proper position. No specialtools are necessary for switching.
Retreaction Bushing Red Pointer Nozzle
Isolation Disc Lock Hasp Index Shaft
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
possibility of inadvertently closing ablock valve either upstream ordownstream of the intended activepressure relief valve.
• Overpressure protection of processmaintained at all times duringswitchover.
• Compact and low weight.
• Lower installation costs than withconventional methods. No fieldfabrication or multiple crane liftsrequired.
• Single, minimally sized penetrationinto vessel, single discharge headerconnection.
• Anderson Greenwood offers acompletely coordinated, tested, andassembled package consisting of thepressure relief devices and inlet andoutlet Safety Selector Valves. The installed interconnecting linkageensures that both inlet and outletSafety Selector Valves switchsimultaneously.
• Ease of Engineering: No need to useoversized piping and valves toprevent excessive pressure loss.Safety Selector Valves in tandem areof the same line size as the pressurerelief valve flanges.
• Assurance of less than 3% pressuredrop to the pressure relief valve inletwhen used with the largest APIorifice available in a given valve size.
Tandem Safety Selector Valve
The Anderson Greenwood TandemSafety Selector Valve System allows forsimultaneous selection of pressure reliefvalve and corresponding dischargeoutlet piping of dual pressure reliefdevices discharging into a closed headersystem.
These redundant pressure relief device systems can be heavy and bulky, requiresignificant field fabrication, installationtime and expense, and can be difficultand confusing to operating personnel.
The Anderson Greenwood TandemSafety Selector Valve System providesa better, safer alternative.
Redundant pressure relief valvesdischarging into a closed header systemutilize all of the inherent advantages ofthe Anderson Greenwood SafetySelector Valves. The two pressure reliefvalves, two safety selector valves, and asimple linkage are pre-assembled at thefactory. Only one flanged inlet and oneflanged outlet connection are required tobe made up in the field. The linkagebetween the inlet and outlet pressurerelief valves is simple, foolproof, andprovides positive and simultaneousswitching of the Selector Valves.
End your concern about closing off thewrong outlet block valve. Overpressure protection is available 100% of the time.
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
Inlet Flange Outlet Flange Tandem SSV Envelope API Inlet by ANSI Pressure Face ANSI Pressure Face Dimensions, inches [mm]Orifice Outlet Size Class Type Class Type A B
Note1. Calculated using 1/16-inch thick gaskets for
RF connections and the spacing listed inTable 5 of ANSI B16.5 for RJ connections.
Tandem SSVwith PRV’sA
B
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
Inlet Flange Outlet Flange Tandem SSV Envelope API Inlet by ANSI Pressure Face ANSI Pressure Face Dimensions, inches [mm]Orifice Outlet Size Class Type Class Type A B
Note1. Calculated using 1/16-inch thick gaskets for
RF connections and the spacing listed inTable 5 of ANSI B16.5 for RJ connections.
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
Inlet Flange Outlet Flange Tandem SSV Envelope API Inlet by ANSI Pressure Face ANSI Pressure Face Dimensions, inches [mm]Orifice Outlet Size Class Type Class Type A B
Tandem SSVwith PRV’sA
B
Anderson Greenwood Safety Selector ValveDual Pressure Relief Device System
Dimensions and Weights – Tandem Safety Selector Valve With Direct Spring Valves
Tandem Safety Selector Valve With API 526 Direct Spring Operated PRV’s
Notes1. Calculated using 1/16-inch thick gaskets for RF connections and the spacing listed in Table 5 of ANSI
B16.5 for RJ connections.
2. Contact factory for dimensions using Crosby JOS-E/JBS-E/JLT-E pressure relief valves.
Inlet Flange Outlet Flange Tandem SSV Envelope API Inlet by ANSI Pressure Face ANSI Pressure Face Dimensions, inches [mm]Orifice Outlet Size Class Type Class Type A B
Tyco Flow Control (TFC) provides the information herein in good faith but makes no representation as to its comprehensiveness or accuracy. This data sheet is intended only as a guide to TFC products and services.Individuals using this data sheet must exercise their independent judgment in evaluating product selection and determining product appropriateness for their particular purpose and system requirements. TFCMAKES NO REPRESENTATIONS OR WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSEWITH RESPECT TO THE INFORMATION SET FORTH HEREIN OR THE PRODUCT(S) TO WHICH THE INFORMATION REFERS. ACCORDINGLY, TFC WILL NOT BE RESPONSIBLE FOR DAMAGES (OF ANY KIND ORNATURE, INCLUDING INCIDENTAL, INDIRECT, OR CONSEQUENTIAL DAMAGES) RESULTING FROM THE USE OF OR RELIANCE UPON THIS INFORMATION. Patents and Patents Pending in the U.S. and foreign countries. Tyco reserves the right to change product designs and specifications without notice.
OptionsO – Standard (Inlet Valve)T – Tandem (Outlet Valve)B – Built per ASME Boiler and Pressure Vessel Code Section I, Code Case 2254 (see page 3)X – Special - note on order required options
Ordering Information
Notes1. Hastelloy® is a registered trademark of
Haynes International.2. Inconel® and Monel® are registered