ANSI泄漏等级

PERFORMANCEENGINEEREDSVFFlowControls,Inc.13560LarwinCircleSantaFeSprings,CA90670562-802-2255SVFLeakageClassificationsofControlValvesClassificationofseatleakagethroughcontrolvalvesControlvalvesaredesignedtothrottleandnotnecessarytoclose100%.Acontrolvalve'sabilitytoshutoffhastodowithmanyfactorsasthetypeofvalvesforinstance.Adoubleseatedcontrolvalvehaveverypoorshutoffcapability.Theguiding,seatmaterial,actuatorthrust,pressuredrop,andthetypeoffluidcanallplayapartinhowwellaparticularcontrolvalveshutsoff.SeatLeakageClassificationsThereareactuallysixdifferentseatleakageclassificationsasdefinedbyANSI/FCI70-21976(R1982).Themostcommonusedare•CLASSIV•CLASSVICLASSIVisalsoknownasmetaltometal.Itisthekindofleakagerateyoucanexpectfromavalvewithametalplugandmetalseat.CLASSVIisknownasasoftseatclassification.SoftSeatValvesarethosewhereeithertheplugorseatorbotharemadefromsomekindofcompositionmaterialsuchasTeflonorsimilar.ValveLeakageClassificationsClassI-ValveLeakageClassificationsIdenticaltoClassII,III,andIVinconstructionanddesignintent,butnoactualshoptestismade.ClassIisalsoknownasdusttightandcanrefertometalorresilientseatedvalves.ClassII-ValveLeakageClassificationsIntendedfordoubleportorbalancedsingeportvalveswithametalpistonringsealandmetaltometalseats.•0.5%leakageoffullopenvalvecapacity.•ServicedPor50psid(3.4bardifferential),whicheverislowerat50to125oF.•Testmediumairat45to60psigisthetestfluid.PERFORMANCEENGINEEREDSVFFlowControls,Inc.13560LarwinCircleSantaFeSprings,CA90670562-802-2255SVFTypicalconstructions:•Balanced,singleport,singlegraphitepistonring,metalseat,lowseatload•Balanced,doubleport,metalseats,highseatloadClassIII-ValveLeakageClassificationsIntendedforthesametypesofvalvesasinClassII.•0.1%leakageoffullopenvalvecapacity.•ServicedPor50psid(3.4bardifferential),whicheverislowerat50to125oF.•Testmediumairat45to60psigisthetestfluid.Typicalconstructions:•Balanced,doubleport,softseats,lowseatload•Balanced,singleport,singlegraphitepistonring,lappedmetalseats,mediumseatloadClassIV-ValveLeakageClassificationsIntendedforsingleportandbalancedsingleportvalveswithextratightpistonsealsandmetalto-metalseats.•0.01%leakageoffullopenvalvecapacity.•ServicedPor50psid(3.4bardifferential),whicheverislowerat50to125oF.•Testmediumairat45to60psigisthetestfluid.Typicalconstructions:•Balanced,singleport,Teflonpistonring,lappedmetalseats,mediumseatload•Balanced,singleport,multiplegraphitepistonrings,lappedmetalseats•Unbalanced,singleport,lappedmetalseats,mediumseatload•ClassIVisalsoknownasmetaltometalPERFORMANCEENGINEEREDSVFFlowControls,Inc.13560LarwinCircleSantaFeSprings,CA90670562-802-2255SVFClassV-ValveLeakageClassificationsIntendedforthesametypesofvalvesasClassIV.•Thetestfluidiswaterat100psigoroperatingpressure.•Leakageallowedislimitedto5x10mlperminuteperinchoforificediameterperpsidifferential.•ServicedPat50to125oF.Typicalconstructions:•Unbalanced,singleport,lappedmetalseats,highseatload•Balanced,singleport,Teflonpistonrings,softseats,lowseatload•Unbalanced,singleport,softmetalseats,highseatloadClassVI-ValveLeakageClassificationsClassVIisknownasasoftseatclassification.SoftSeatValvesarethosewheretheseatorshut-offdiscorbotharemadefromsomekindofresilientmaterialsuchasTeflon.Intendedforresilientseatingvalves.•Thetestfluidisairornitrogen.•Pressureisthelesserof50psigoroperatingpressure.•Theleakagelimitdependsonvalvesizeandrangesfrom0.15to6.75mlperminuteforvalvesizes1through8inches.PortDiameterinchesMillimetersBubblesperminutemlperminute12510.1511/23820.3025130.4521/26440.6037660.904102111.706152274.008203456.7510254639123058111.5Typicalconstructions:•Unbalanced,singleport,softseats,lowloadPERFORMANCEENGINEEREDSVFFlowControls,Inc.13560LarwinCircleSantaFeSprings,CA90670562-802-2255SVFControlValveLeakageClassification-OverviewLeakageClassDesignationMaximumLeakageAllowableTestMediumTestPressureTestingProceduresRequiredforEstablishingRatingIxxxNotestrequiredII0.5%ofratedcapacityAirorwaterat50-125oF(10-52oC)45-60psigormaximumoperatingdifferentialwhicheverislower45-60psigormaximumoperatingdifferentialwhicheverislowerIII0.1%ofratedcapacityAsaboveAsaboveAsaboveIV0.01%ofratedcapacityAsaboveAsaboveAsaboveV0.0005mlperminuteofwaterperinchofportdiameterperpsidifferentialWaterat50to125oF(10to52oC)MaximumservicepressuredropacrossvalveplugnottoexceedANSIbodyratingMaximumservicepressuredropacrossvalveplugnottoexceedANSIbodyratingVINottoexceedamountsshowninthetableaboveAirornitrogenat50to125oF(10to52oC)50psigormaxrateddifferentialpressureacrossvalveplugwhicheverislowerActuatorshouldbeadjustedtooperatingconditionsspecifiedwithfullnormalclosingthrustappliedtovalveplugseat