ANDERSON GREENWOOD - Mramco

1 ANDERSON GREENWOOD Low pressure POPRV CatalogSeries 90 and 9000 Pilot operated pressure relief ValvesTotal Flow Control Solutions Copyright 2008 Tyco Flow Control. All rights ControlFeatures and Benefits Tight Up to Set pressure :Pilot control keeps high seat forces allthe way to set point, eliminatingproduct losses. Full Open at Set Point:Snap action opening permits fullopening at set pressure , allowing forhigher settings and overcomingfreezing or sticking problems. Pop or Modulating Action:Pilot selection allows a choicebetween rapid snap opening actionand proportional modulating action tobest suit the process. Resilient Seats and Diaphragms:Extensive selection of seat anddiaphragm materials to meet mostconditions and provide longmaintenance-free operation. Balanced Against Back pressure : valves can be connected to closedheader systems without loss of valvelift or set pressure fluctuations. Remote Sensing:This option permits the pressure inthe protected system to be accuratelysensed at the PRV regardless of theinlet piping pressure losses to thePRV.

2 Field Test Connection:Valve function can be verified in placewithout removing the valve to a testbench or raising process pressures. Manual Blowdown:The valve can be actuated manuallyor remotely to depressurize a 90 and 9000 valves offer a high performancealternative to spring and weight-loaded relief devicesfor low pressure GREENWOOD is either a trademark or registered trademark of Tyco International Services AG or itsaffiliates in the United States and/or other countries. All other brand names, product names, or trademarksbelong to their respective GREENWOOD Low pressure POPRV CatalogSeries 90 and 9000 Pilot operated pressure relief ValvesProduct Overview2 FunctionLow pressure POPRV2, 3 OperationSeries 904, 5 Series 90006, 7 Type 96A Vacuum Breaker 8 General Technical Data9 Model Selection10 - 16 Product DetailType 93 17 Types 91 and 94 18 Type 95 19 Type 9200 20 Type 9300 21 Series 90 Pilot 22, 23 Series 400 Pilot 24 Type 96A 25 Accessories and Options26 - 29 Dimensions and WeightsTypes 93, 91 and 94, 95 30 Types 9200, 9300 31, 32 Type 96A 32 Sizing33 - 38 Capacity Tables 39 - 50 Ordering Information51 - 52 Product OverviewThe Series 90 and 9000 group of productsis a very wide range of both pressure andvacuum relief valves , primarily designedfor protecting low pressure storage vesselsand tanks, as well as low pressure pipingsystems.

3 They are designed to meet therequirements of ASME VIII and API 2000;many models also satisfy IMO and othermarine 93:The Type 93 is the originalworkhorse of the product range, providingexcellent service since 1968. This pilotoperated pressure relief valve is designedwith elastomer seats and seals, withconstruction materials in aluminum,carbonsteel (CS) and stainless steel (SS)to satisfy the majority of gas piping andchemical tank 91 and 94:The Types 91 and 94were designed for specific applicationswhere FEP diaphragms alone were notruggedenough and premium sealing wasrequired for super cryogenic Types 91 and 94 employ a bellowscoupled with a Teflon film seat to provideextraordinary performance for hard-to-holdcryogenic fluids such as hydrogen andhelium. They also satisfy specific 95:The Type 95 is a unique higherpressure protection valve that utilizes apiston in the main valve for ruggedness, andhigh performance elastomers, making thisvalve ideal for special applications up to 150 psig [ barg] in marine LPG 96A:All of the above valves are pilotoperated pressure relief valves .

4 The Type96A is a weight-loaded vacuum breakerdesigned to compliment the pressure 9200 and 9300:The Types 9200and 9300 were designed in 1986 to expandupon the capabilities of the Series 90product range. The Types 9200 and 9300employ the highly successful pressurizedTeflon film seat, as well as protected FEPdiaphragms. The designs allow thesevalves to be used in the pilot operatedpressure relief mode and simultaneouslyprovide vacuum relief , either via weightloads of the internals, or with a specificpilot control of the vacuum opening. TheTypes 9200 and 9300 were designed witha special studded inlet connection toreduce the inlet profile, and coupled withlarger orifice areas, these valves provideflow capacities as much as 45 percentgreater than the Series 90 valves . The Type 9300 is a full body valve to pipe awaythe discharge if required. The 9200 ventsdirectly to atmosphere and has noprovision to pipe away the Low PressurePOPRVLow pressure systems can be protectedfrom overpressure by spring-operatedvalves, weight-loaded valves or pilot- operated Open at Set PressureWeight-loaded and spring- operated valvesbegin to open when forces are inequilibrium.

5 As process pressuresapproach set pressures, there can besignificant simmer or leakage and loss periods of simmer can leadto valve freeze-up with cryogenic small differential forces don t easilyovercome sticky fluids and prevent properopening. Typical weight-loaded valvesrequire significant overpressure to achieverated capacities (see Figure 1).Note1. Teflon is a registered trademark of de Nemours : The application of the 90 and 9000 Series flowing style pilot operatedpressure relief valves in condensable gasservice (ie: n-Butane, Isobutane orButadiene) with operating fluid saturationtemperatures that fall within the expectedambient temperature extremes requirespecial consideration to assure the valvetemperature remains above the operatingfluid saturation temperature. Pleasecontact the factory to review all applica-tions which fall within this LoadedSeries 90/9000102030405060708090100010 20 30 40 50 60 70 80 90 100 SetPressure100%%Overpressure%RelievingCa pacityCopyright 2008 Tyco Flow Control.

6 All rights 1 Pilot operated valves use a pilot to controlpressure over a large unbalanced memberin the main valve, such as a diaphragm or piston (see Figure 2). The largeoverbalance means a much larger force on top of the seat compared to processforces pushing up on the seat. At setpressure, the pilot relieves the pressurequickly, permitting the main valve seat toopen rapidly. The ANDERSON GreenwoodSeries 90 and 9000 designs can provide fullopening without any overpressure, acapability unavailable in spring-operatedand weight-loaded valves in low same feature can be applied to theAnderson GREENWOOD Series 9000 forvacuum, allowing tight sealing operation inavacuum mode until such point where thevalve must rapidly open to prevent Action or Modulating ActionOpeningWeight-loaded and spring- operated valvesopen as process forces overcomedownward forces, with little flexibility toovercome problem applications. AndersonGreenwood pilot operated valves can beadjusted to open with a rapid snap actionor modulating action.

7 Most applications arewell served by the snap action mode, withfull opening at set pressure and fullreseating after a short blowdown. However,some systems might best be served by aproportional opening, whereby the valveopens just enough to satisfy small upsetsand maintain constant system pressure ,yet still have the capability to reach fullcapacity within 10 percent ANDERSON GREENWOOD Series 90 and9000 can be set for a snap acting ormodulating mode with a simple adjustmentof the external blowdown screw. No partchanges are necessary to change theoperating Selection of ModelsThe Series 90 and 9000 valves are offeredin a wide variety of sizes, materials andconfigurations to meet most applicationsfor positive pressure and vacuumprotection. ANDERSON GREENWOOD hasdecades of experience in cryogenic,industrial, and chemical applications. Eachapplication benefits from the samefeatures of leak-free operation, balancedagainst back pressure , as well as preciseand repeatable OperationWeight-loaded and spring- operated valveshave decreasing seating forces as setpressure is approached.

8 This leads tosignificant leakage of valuable productprior to set point. With the AndersonGreenwood pilot operated valves , thegreater the system pressure , the higherthe seating force, until set point is reachedand the valve provides superior leak-free operation,minimizing product loss. Figure 3illustrates the relative seating forces of thevalve Against Back PressureLow- pressure weight-loaded and spring- operated valves are directly affected by anyback pressures, built-up or , any vent piping or closed headersystem can adversely affect the openingand capacities of these valves . Such valvesshould not be used when discharging intoclosed header systems. Figure 4 illustratesa typical weight-loaded design, where anyback pressures will directly increase theopening pressure of such designs, or addto premature closing and GREENWOOD pilot operated valveswill not increase in set pressure or lose liftdue to back pressure , as they are inherentlybalanced against back GREENWOOD Low pressure POPRV CatalogSeries 90 and 9000 Pilot operated pressure relief ValvesCopyright 2008 Tyco Flow Control.

9 All rights Low pressure POPRV (continued)BackPressureFigure 40%%of Set pressure %AvailableSeating Force50%90%100%Set Pressure0%10%50%90%100%High Seating ForceLow Seating ForceLow PressurePilot OperatedPressure ReliefValveWeight-loadedSafety ValveFigure 3 DomeMain ValveNozzlePilotDiaphragmFFigure 2 ANDERSON GREENWOOD Low pressure POPRV CatalogSeries 90 and 9000 Pilot operated pressure relief ValvesCopyright 2008 Tyco Flow Control. All rights Series 90 Figure 5(Closed)Positive pressure ReliefUnder normal operating conditions, systempressure acts on the bottom of the mainvalve seat, on top of the main valvediaphragm, and on the pilot main valve seat is held tightly closedby a large force equal to the systempressure times the unbalanced area of themain valve pressure is also applied to theboost cavity and the sense cavitydownstream of the variable soft pilot seat is held closed as thepilot spring load is greater than the upwardforces acting on the sense Seal DiaphragmSense DiaphragmPilot SpringBoost DiaphragmSense CavityBoost CavityPilot SeatBlowdown AdjustmentOrifice (variable)Main Valve DiaphragmFixed OrificeDomeMain Valve SeatPilot Pickup(total pressure )System PressureExhaust PressureAnderson GREENWOOD Low pressure POPRV CatalogSeries 90 and 9000 Pilot operated pressure relief ValvesCopyright 2008 Tyco Flow Control.

10 All rights 6(Pilot Open)Positive pressure ReliefWhen process pressure increases to thepoint where the upward force on the sensediaphragm exceeds the spring load, thepilot seat lifts slightly, setting up a smallflow in the pilot sense small flow across the blowdown adjustmentorifice causes a reduction in pressuredownstream of the orifice and in the sensecavity. Even though this is only a smallreduction in pressure , it creates a large netupward force which snaps the pilot fullopen as shown in Figure 7(Open and Flowing)Positive pressure ReliefWith the pilot fully open, a large reductionin pressure on top of the main valvediaphragm occurs, resulting in full lift of themain valve seat. Set pressure is where themain valve through the main valve continues untilsystem pressure has been reduced to thepoint where the pilot spring is again able toovercome the lifting forces on the boostdiaphragm. As the pilot begins to close, the flow and pressure drop across theblowdown adjustment and orificedecreases.