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A/DV2"-18780PistonCheckValves1.FP&LJPN-SPSL-96-0372,August16,1996Letter2.NDVS.O.'sET401andRZ8143.NDVTestReportNo.'sRZ814,TestReportofFlowTestona2"-18780GlobePistonCheckValve,October2,1996Gentlemen:NDVapologizesforthedelayinrespondingtothereferencedFP&Lletter.Wehadhopedtoreceiveapplicationresponsestoournotificationlettersbutasofthiswritingwehavenotreceivedanycompleteinformation.NDVhasperformedadesignreviewofthepistoncheckvalvewiththeintenttoaddressthefunctionalandre-assemblyproblemsexperiencedatSt.Lucie.Thefollowingareaswereaddressedasnoted: | A/DV2"-18780PistonCheckValves1.FP&LJPN-SPSL-96-0372,August16,1996Letter2.NDVS.O.'sET401andRZ8143.NDVTestReportNo.'sRZ814,TestReportofFlowTestona2"-18780GlobePistonCheckValve,October2,1996Gentlemen:NDVapologizesforthedelayinrespondingtothereferencedFP&Lletter.Wehadhopedtoreceiveapplicationresponsestoournotificationlettersbutasofthiswritingwehavenotreceivedanycompleteinformation.NDVhasperformedadesignreviewofthepistoncheckvalvewiththeintenttoaddressthefunctionalandre-assemblyproblemsexperiencedatSt.Lucie.Thefollowingareaswereaddressedasnoted: | ||
A.PrreeI/BonnAreImBonnetRetainerCapscrewsFP8LreportedhavingdifficultyinsealingtheADVansealusingthecapscrewwithoutpressure.Thecurrentcapscrewisa5/16"diametercapscrew.A1/2"diametercapscrewwillbeusedinthefuture.Thiswillprovideapproximatelythree(3)timesthegasketload.2.GallingoftheBonnetRetainerThreadsFPBLhasexperiencedgallingofthebonnetretainerthreads.The.currentretainerismadeof316stainlesssteelwithchromeplated12seriesthreads.NDVisevaluatingreplacingthisdesignwitha17-4PHbonnetretainer(nochromeplating)with8seriesthreads.Assumingsuccessfulcompletionofthenewbonnetretainerevaluation,thisdesignwillbeputinplace.A/DVplanstoincludethephilosophyofbothenhancementwiththesmallerpistoncheckvalves.Thesetwo(2)enhancementswillaffectinventoryandpartinterchangeability.B.CIninDinfVlvsPriorhimenNDVhasevaluatedseveralmethodstoassurecompletedryingofthepistoncheckvalvespriortoshipment,i.e.disassembly,baking,etc.Wehaveconcludedthatthemosteffectivemethodistodisassemblethevalvesafterhydrostatictesting,drythepartsandreassemblewithoutthegasketandanti-rotationpin(PartNo.258)installed.Thegasketandanti-rotationpinwillbepackagedwiththevalveandatagplacedonthevalverequiringinstallationofthesetwo(2)partsaftervalveinstallation.VIvPerfrmnceFnionalImDiscGuideAreaofBodyNeckBoreWeevaluatedthisareatodetermineifthebodyguidescouldbeimproved.Severalmethodswereevaluated,i.e.,steevingthebodyborewithhardenedmaterial,reshapingtheexhaustport,etc.Allmethodsarecostly.Theconclusionwasreachedthattheabovechangeswerecostprohibitiveandthebetterresolutionistouseasmallervalveforoscillatingflowapplicationinordertoplacethediscinamoreopenpositionwhereitisbetterguidedbythebody. | A.PrreeI/BonnAreImBonnetRetainerCapscrewsFP8LreportedhavingdifficultyinsealingtheADVansealusingthecapscrewwithoutpressure.Thecurrentcapscrewisa5/16"diametercapscrew.A1/2"diametercapscrewwillbeusedinthefuture.Thiswillprovideapproximatelythree(3)timesthegasketload.2.GallingoftheBonnetRetainerThreadsFPBLhasexperiencedgallingofthebonnetretainerthreads.The.currentretainerismadeof316stainlesssteelwithchromeplated12seriesthreads.NDVisevaluatingreplacingthisdesignwitha17-4PHbonnetretainer(nochromeplating)with8seriesthreads.Assumingsuccessfulcompletionofthenewbonnetretainerevaluation,thisdesignwillbeputinplace.A/DVplanstoincludethephilosophyofbothenhancementwiththesmallerpistoncheckvalves.Thesetwo(2)enhancementswillaffectinventoryandpartinterchangeability.B.CIninDinfVlvsPriorhimenNDVhasevaluatedseveralmethodstoassurecompletedryingofthepistoncheckvalvespriortoshipment,i.e.disassembly,baking,etc.Wehaveconcludedthatthemosteffectivemethodistodisassemblethevalvesafterhydrostatictesting,drythepartsandreassemblewithoutthegasketandanti-rotationpin(PartNo.258)installed.Thegasketandanti-rotationpinwillbepackagedwiththevalveandatagplacedonthevalverequiringinstallationofthesetwo(2)partsaftervalveinstallation.VIvPerfrmnceFnionalImDiscGuideAreaofBodyNeckBoreWeevaluatedthisareatodetermineifthebodyguidescouldbeimproved.Severalmethodswereevaluated,i.e.,steevingthebodyborewithhardenedmaterial,reshapingtheexhaustport,etc.Allmethodsarecostly.Theconclusionwasreachedthattheabovechangeswerecostprohibitiveandthebetterresolutionistouseasmallervalveforoscillatingflowapplicationinordertoplacethediscinamoreopenpositionwhereitisbetterguidedbythebody. | ||
C.ValvePertrmanOFuncIonIItems(Conttnued)2.Disc-BodyMaterialCouplettwasstatedbyFP8Lthatfrettingismoreapttooccurwherealargedifferenceinmaterialhardnessexists.A/DVselectedthebody-discmaterialcoupleforwearresistance,gallingresistanceandcastability,weldabilityofthebodies.Amoreimportantfactortoreducethepotentialforfrettingisreducedstresslevels.NDVdoesnotplantochangethebodyordiscmaterials.AsdiscussedinA.1.aboveandinthelaterrootcauseanalysis,useofasmallervalvewouldresolvethissituation.RoughMachiningleftintheBodyNeckBoreInMay,1993,NDVhadchangeditsroughmachiningprocesstosetupandroughcuttheneckboreandseatpocketusingthesamesetupmethodandsinglepointtooling-boringasthefinishmachiningprocess.Priortothistimetheneckborewasroughmachinedonaradialdrill.Thisdrillingprocesswasnotalwaysperformedonthesamecenterlineasthefinalmachiningandthedrillhadatendencytotailoffcenter.ThisareahasbeenresolvedasdescribedaboveinMay,1993.RatioGuideLength-DiscDiameterNDV'sdesigncriterialimitsthepotentialdisctilttolessthan1/2'ndrequiresaratioofone(1)orgreaterforthedisc,guidelengthtodiameter.The2"-1878¹PistonCheckdischasaratioof1.12:1.BothNDV'sdesigncriteriaandthe2"-1878¹designarerepresentativeofNDVandcompetitivevalvedesignswhichhavebeenproventobesuccessfulinmostservices.RooCsNDVevaluatedtheasfoundconditionofthepistoncheckvalvethatstuckopen.Toassistinourrootcauseanalysis,weperformedflowtestsontwo(2)2"-1878¹PistonCheckvalves(one(1)valvereturnedfromFP&L,S/NET401 6).ReferenceNo.3Report,enclosed,documentsthetaskandresults.Thetestingwasperformedtoevaluatevalveperformanceatvariousforwardflowrates.Thetestconclusionwasthevalvealwaysclosedwhenforwardflowended. | C.ValvePertrmanOFuncIonIItems(Conttnued)2.Disc-BodyMaterialCouplettwasstatedbyFP8Lthatfrettingismoreapttooccurwherealargedifferenceinmaterialhardnessexists.A/DVselectedthebody-discmaterialcoupleforwearresistance,gallingresistanceandcastability,weldabilityofthebodies.Amoreimportantfactortoreducethepotentialforfrettingisreducedstresslevels.NDVdoesnotplantochangethebodyordiscmaterials.AsdiscussedinA.1.aboveandinthelaterrootcauseanalysis,useofasmallervalvewouldresolvethissituation.RoughMachiningleftintheBodyNeckBoreInMay,1993,NDVhadchangeditsroughmachiningprocesstosetupandroughcuttheneckboreandseatpocketusingthesamesetupmethodandsinglepointtooling-boringasthefinishmachiningprocess.Priortothistimetheneckborewasroughmachinedonaradialdrill.Thisdrillingprocesswasnotalwaysperformedonthesamecenterlineasthefinalmachiningandthedrillhadatendencytotailoffcenter.ThisareahasbeenresolvedasdescribedaboveinMay,1993.RatioGuideLength-DiscDiameterNDV'sdesigncriterialimitsthepotentialdisctilttolessthan1/2'ndrequiresaratioofone(1)orgreaterforthedisc,guidelengthtodiameter.The2"-1878¹PistonCheckdischasaratioof1.12:1.BothNDV'sdesigncriteriaandthe2"-1878¹designarerepresentativeofNDVandcompetitivevalvedesignswhichhavebeenproventobesuccessfulinmostservices.RooCsNDVevaluatedtheasfoundconditionofthepistoncheckvalvethatstuckopen.Toassistinourrootcauseanalysis,weperformedflowtestsontwo(2)2"-1878¹PistonCheckvalves(one(1)valvereturnedfromFP&L,S/NET401-9-6).ReferenceNo.3Report,enclosed,documentsthetaskandresults.Thetestingwasperformedtoevaluatevalveperformanceatvariousforwardflowrates.Thetestconclusionwasthevalvealwaysclosedwhenforwardflowended. | ||
EgAsaresultofourevaluationoftheFPBLfailedvalveandourtesting,wehaveconcludedthattherootcauseisthediscoscillation,causedbythereciprocatingpump,causingfrettingtotakeplaceinthevalvebodydiscguidearea.Thefrettingareaprovidesaconfigurationinthebodyguidethatallowsthedisctostickopenwithoutforwardflowandwithreverseflow.A/DV'srecommendationstoeliminatethevalveoperationalproblemare(preferredlistedfirst):A.Useofin-linecheckvalvesinreciprocatingpumpapplications.Thisvalvedesignprovidesbetterwearresistantmaterialsasdiscguidesthroughouttheentirevalvestroke.~~Useofsmallerpistoncheckvalve(valvesizeorreducedport)inreciprocatingpumpapplicationstomorefullyopenthediscwherebetterbody-discguidingisavailable.AttachedaregraphsofflowrateversusdiscpositionandCvversusdiscpositiontobeusedtoevaluateT-patternpistoncheckvalvesizeselection.WhereasmallerT-patternpistoncheckvalve~producestoohighapressuredrop,useofaY-patternpistoncheckvalvemayresolvethisconcern.T-patternandY-patternpistoncheckvalvesandin-linecheckvalvesarewithinA/DY'sproductlines.AvailabilityofY-patternpistoncheckvalvesissclleduledforthesecondquarterof1997.lffurtherdiscussionisrequiredontheabove,pleasefeelfreetocontactus.ANCHOR/DARLINGVALVECOMPANYFloydA.Bensinger,P.E.Manager-Engineeringbcc:J.ChappellT.JohnsonW.Knecht'G;KneiserR.MaiettaG.ParksJ.TarbuttonH.WescottF.Velez 502"8cSmallerT-PistonCheckValvesFlowCoefficient(Cv)vs.DiscPosition~~FAB01-Nov-9640CEJ030201000%20%40%60%80%100%1/2"PCsO1-1/2"PCsDisc%Open+3/4"Bc1"PCs2"PCs 3502"8cSmaIIetT-PistonCheckVaIvesAirFlowRote(cfm)vs.DiscPosition~~FAB01-Nov-963002502001501005000%20%40%60%80%100%1/2",3/4"8c1"P.CsDisc%Open+1-1/2"PCs<>2"PCs 2602"BcSmallerT-PistonCheckValvesWaterFlowRote(gpm)vs.DiscPosition~~FAB01-Nov-96240220200180160140120.100.8060402000%20%40%60%80%100%1/2",3/4"Bc1"PCsDisc%Open+1-1/2"PCs<>2"PCs PARTCTYNO001IBOOTDESCRIPTION002I004I015IBONNETDISCSEATRINC050IPRESSURESEALCASKET052ISPACERRING054IBOMNETRETAINERSASSI~5MSA47~16SA65IP560TYPEIA276.S21600AGRAPHITEA47~16SA479-516MATERIALREVISIONSDELETEDMOTE5:OYSN,ADDEDMofdseTHRUlo.CUSTOMERNOTEADOEOUNITSAANOVALVEDATASHEETNO.DELETEDCUST.P.o.No.dcMOVEDA/OVS.o.No.TALEBLOCK:DELETED"CLOSEACWIHI2215I256I260I545IBONNETCAPSCREWANTHIOTATIONPINWIRENAMEPLATEA574AISI502(SPRINCTTPEER516AISI504545IIDENTIFICATIONPLATEAISI504429ISPRINGINCONELXI.VALVEISASMECLASSIPER1965ASMKSKCTIOMR2.APPROXVALVEWEIGHT24LBS5.APPROXCV564.PISTONCHECKVALVEDESIGNEDFORMOUMTINCINAHORIZONTALRUNOFPIPEWITHVALVEENDSHORIZONTALANDBONNETONTOP5.VALVEDESICNPRESSUREIS2755PSIAT6doFNOTES7.4-ASMKPRESSUREBOUNDARYPARTd.CRACKIMCPRESSURE5PSI9.ANSI1676STANDARDINTERPOLATEDPRESSURECLASSlo.HYDROSTATICTESTINFORMATION:SHELLSEATPRESSURE(PSI)57754956ALLOWABLKLEAKAGE(CC/HR)03d.MINIMUMFLOWDIAMDER1.500SEATRINGINSIDEDWlETER~1.500DURATION(MIN)10525d~ooo5~FO0)COO!0COCIILOWElO.Vl>COI:IL054215052050002429004001015FLORIDAPOWERRLIGHTCOMPANYST.LUCIEUNITSIR'2SPECIFICATIONNo.:MN5.06VALVEDATASHEKflYDSPSL&IO'Y.~.52MIMFLOWZeo545546df.520MINSECTIONAAET401%ANCHORDARLINGVALVECOMPANY2"-1878FULLPORTSOCKETENDSSTAINLESSSTEELPISTONCHECKVALVENONWOBALTTRIMHIP9AIO00302IT'~l'T~ONBY.'AlQ10I92QI9ll212PS71OAPPO6IIRFBegaIO-IIHI2I2545~76 | EgAsaresultofourevaluationoftheFPBLfailedvalveandourtesting,wehaveconcludedthattherootcauseisthediscoscillation,causedbythereciprocatingpump,causingfrettingtotakeplaceinthevalvebodydiscguidearea.Thefrettingareaprovidesaconfigurationinthebodyguidethatallowsthedisctostickopenwithoutforwardflowandwithreverseflow.A/DV'srecommendationstoeliminatethevalveoperationalproblemare(preferredlistedfirst):A.Useofin-linecheckvalvesinreciprocatingpumpapplications.Thisvalvedesignprovidesbetterwearresistantmaterialsasdiscguidesthroughouttheentirevalvestroke.~~Useofsmallerpistoncheckvalve(valvesizeorreducedport)inreciprocatingpumpapplicationstomorefullyopenthediscwherebetterbody-discguidingisavailable.AttachedaregraphsofflowrateversusdiscpositionandCvversusdiscpositiontobeusedtoevaluateT-patternpistoncheckvalvesizeselection.WhereasmallerT-patternpistoncheckvalve~producestoohighapressuredrop,useofaY-patternpistoncheckvalvemayresolvethisconcern.T-patternandY-patternpistoncheckvalvesandin-linecheckvalvesarewithinA/DY'sproductlines.AvailabilityofY-patternpistoncheckvalvesissclleduledforthesecondquarterof1997.lffurtherdiscussionisrequiredontheabove,pleasefeelfreetocontactus.ANCHOR/DARLINGVALVECOMPANYFloydA.Bensinger,P.E.Manager-Engineeringbcc:J.ChappellT.JohnsonW.Knecht'G;KneiserR.MaiettaG.ParksJ.TarbuttonH.WescottF.Velez 502"8cSmallerT-PistonCheckValvesFlowCoefficient(Cv)vs.DiscPosition~~FAB01-Nov-9640CEJ030201000%20%40%60%80%100%1/2"PCsO1-1/2"PCsDisc%Open+3/4"Bc1"PCs2"PCs 3502"8cSmaIIetT-PistonCheckVaIvesAirFlowRote(cfm)vs.DiscPosition~~FAB01-Nov-963002502001501005000%20%40%60%80%100%1/2",3/4"8c1"P.CsDisc%Open+1-1/2"PCs<>2"PCs 2602"BcSmallerT-PistonCheckValvesWaterFlowRote(gpm)vs.DiscPosition~~FAB01-Nov-96240220200180160140120.100.8060402000%20%40%60%80%100%1/2",3/4"Bc1"PCsDisc%Open+1-1/2"PCs<>2"PCs PARTCTYNO001IBOOTDESCRIPTION002I004I015IBONNETDISCSEATRINC050IPRESSURESEALCASKET052ISPACERRING054IBOMNETRETAINERSASSI~5MSA47~16SA65IP560TYPEIA276.S21600AGRAPHITEA47~16SA479-516MATERIALREVISIONSDELETEDMOTE5:OYSN,ADDEDMofdseTHRUlo.CUSTOMERNOTEADOEOUNITSAANOVALVEDATASHEETNO.DELETEDCUST.P.o.No.dcMOVEDA/OVS.o.No.TALEBLOCK:DELETED"CLOSEACWIHI2215I256I260I545IBONNETCAPSCREWANTHIOTATIONPINWIRENAMEPLATEA574AISI502(SPRINCTTPEER516AISI504545IIDENTIFICATIONPLATEAISI504429ISPRINGINCONELXI.VALVEISASMECLASSIPER1965ASMKSKCTIOMR2.APPROXVALVEWEIGHT24LBS5.APPROXCV564.PISTONCHECKVALVEDESIGNEDFORMOUMTINCINAHORIZONTALRUNOFPIPEWITHVALVEENDSHORIZONTALANDBONNETONTOP5.VALVEDESICNPRESSUREIS2755PSIAT6doFNOTES7.4-ASMKPRESSUREBOUNDARYPARTd.CRACKIMCPRESSURE5PSI9.ANSI1676STANDARDINTERPOLATEDPRESSURECLASSlo.HYDROSTATICTESTINFORMATION:SHELLSEATPRESSURE(PSI)57754956ALLOWABLKLEAKAGE(CC/HR)03d.MINIMUMFLOWDIAMDER1.500SEATRINGINSIDEDWlETER~1.500DURATION(MIN)10525d~ooo5~FO0)COO!0COCIILOWElO.Vl>COI:IL054215052050002429004001015FLORIDAPOWERRLIGHTCOMPANYST.LUCIEUNITSIR'2SPECIFICATIONNo.:MN5.06VALVEDATASHEKflYDSPSL&IO'Y.~.52MIMFLOWZeo545546df.520MINSECTIONAAET401%ANCHORDARLINGVALVECOMPANY2"-1878FULLPORTSOCKETENDSSTAINLESSSTEELPISTONCHECKVALVENONWOBALTTRIMHIP9AIO00302IT'~l'T~ONBY.'AlQ10I92QI9ll212PS71OAPPO6IIRFBegaIO-IIHI2I2545~76 | ||
}} | }} | ||
Revision as of 01:51, 2 May 2018
| ML17229A163 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 11/27/1996 |
| From: | KNECHT W G ANCHOR/DARLING VALVE CO. |
| To: | CARTER J NRC |
| References | |
| REF-PT21-96 NUDOCS 9612160224 | |
| Download: ML17229A163 (11) | |
Text
g1ACCESSIONNBR:SCIL:50-33550-389AUTH.NAMEKNECHTFW.G.RECIP.NAMECARTER,J.CATEGORYj.REGULATINFORMATIONDISTRIBUTIONSTEM(RIDE)9612160224DOC.DATE:96/11/27NOTARIZED:NOSt.LuciePlant,Unit1,FloridaPower6LightCo.St.LuciePlant,Unit2,FloridaPower6LightCo.AUTHORAFFILIATIONAnchor/DarlingValveCo.RECIPIENTAFFILIATIONNRC-NoDetailedAffiliationGivenDOCKET'00500033505000389
SUBJECT:
Part21reptre2"-1878globepistoncheckvalves.A/DVplanstoincludephilosophyofbothenhancementw/smallerpistoncheckvalves.A/DVevaluatedfoundconditionofpistoncheckvalve,stuckopen.DISTRIBUTIONCODE:IE19TCOPIESRECEIVED:LTRENCLSIZE:TITLE:Part21Rept(50DKT)NOTES:RECIPIENTIDCODE/NAMEPD2-3PDINTERN.ILCENTER0NRR/DRPM/PECBRES/DET/EIBRGN2RGN4EXTERNAL:INPORECORDCTRNRCPDRCOPIESLTTRENCL1111111111111111RECIPIENT1DCODE/NAMEWIENS,L.NRR/DISP/PSXB/BPDRWARD,M.RGNlRGN3NOACSILVERFENUDOCSFULLTXTCOPIESLTTRENCL1111111111111'1DUEOCULPg~~SCAggpoNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFN5D-5(EXT.415-2083)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!FULLTEXTCONVERSIONREQUXREDTOTALNUMBEROFCOPIESREQUIRED:LTTR15ENCL15 Anchor/DarlingValveCompany~Williamsport,PA17701W.G.KNECHTTechnicalDirectorNovember27,1996Mr.JerryCarterUSNRCEventsAssessmentBranchWashingtonDC20555
Subject:
A/DVl878ClassPistonCheckValves
DearMr.Carter:
PerourdiscussionthisdatetheenclosureisthelatestcopyofourreporttoFPSLregardingthepistoncheckvalveproblem.ShouldyouhaveanyquestionspleasedonothesitatetocallFloydBensinger,ourEngineeringManager,orthewriter.Sincerely,ANCHOR/DARLINGVALVECOMPMYu,rlW4f-WilliamG.KnechtTechnicalDirectorWGKjscc:F.A.BensingerEnclosure96i2i6022496ii27~iPDRADOCK050003358PDR Anchor/DarlingValveCompany701FIRSTSTREETP.O.SOX3428WILUAMSPORT,PA177014428(717)3274800FAX:(71TJ3274805Page1of4FloridaPowerandLightCompanySt.LuciePlantP.O.Box128FortPierce,FL24954November20,1996Attention:D.J.DenverSt.LucieEngineeringManager
Subject:
Reference:
A/DV2"-18780PistonCheckValves1.FP&LJPN-SPSL-96-0372,August16,1996Letter2.NDVS.O.'sET401andRZ8143.NDVTestReportNo.'sRZ814,TestReportofFlowTestona2"-18780GlobePistonCheckValve,October2,1996Gentlemen:NDVapologizesforthedelayinrespondingtothereferencedFP&Lletter.Wehadhopedtoreceiveapplicationresponsestoournotificationlettersbutasofthiswritingwehavenotreceivedanycompleteinformation.NDVhasperformedadesignreviewofthepistoncheckvalvewiththeintenttoaddressthefunctionalandre-assemblyproblemsexperiencedatSt.Lucie.Thefollowingareaswereaddressedasnoted:
A.PrreeI/BonnAreImBonnetRetainerCapscrewsFP8LreportedhavingdifficultyinsealingtheADVansealusingthecapscrewwithoutpressure.Thecurrentcapscrewisa5/16"diametercapscrew.A1/2"diametercapscrewwillbeusedinthefuture.Thiswillprovideapproximatelythree(3)timesthegasketload.2.GallingoftheBonnetRetainerThreadsFPBLhasexperiencedgallingofthebonnetretainerthreads.The.currentretainerismadeof316stainlesssteelwithchromeplated12seriesthreads.NDVisevaluatingreplacingthisdesignwitha17-4PHbonnetretainer(nochromeplating)with8seriesthreads.Assumingsuccessfulcompletionofthenewbonnetretainerevaluation,thisdesignwillbeputinplace.A/DVplanstoincludethephilosophyofbothenhancementwiththesmallerpistoncheckvalves.Thesetwo(2)enhancementswillaffectinventoryandpartinterchangeability.B.CIninDinfVlvsPriorhimenNDVhasevaluatedseveralmethodstoassurecompletedryingofthepistoncheckvalvespriortoshipment,i.e.disassembly,baking,etc.Wehaveconcludedthatthemosteffectivemethodistodisassemblethevalvesafterhydrostatictesting,drythepartsandreassemblewithoutthegasketandanti-rotationpin(PartNo.258)installed.Thegasketandanti-rotationpinwillbepackagedwiththevalveandatagplacedonthevalverequiringinstallationofthesetwo(2)partsaftervalveinstallation.VIvPerfrmnceFnionalImDiscGuideAreaofBodyNeckBoreWeevaluatedthisareatodetermineifthebodyguidescouldbeimproved.Severalmethodswereevaluated,i.e.,steevingthebodyborewithhardenedmaterial,reshapingtheexhaustport,etc.Allmethodsarecostly.Theconclusionwasreachedthattheabovechangeswerecostprohibitiveandthebetterresolutionistouseasmallervalveforoscillatingflowapplicationinordertoplacethediscinamoreopenpositionwhereitisbetterguidedbythebody.
C.ValvePertrmanOFuncIonIItems(Conttnued)2.Disc-BodyMaterialCouplettwasstatedbyFP8Lthatfrettingismoreapttooccurwherealargedifferenceinmaterialhardnessexists.A/DVselectedthebody-discmaterialcoupleforwearresistance,gallingresistanceandcastability,weldabilityofthebodies.Amoreimportantfactortoreducethepotentialforfrettingisreducedstresslevels.NDVdoesnotplantochangethebodyordiscmaterials.AsdiscussedinA.1.aboveandinthelaterrootcauseanalysis,useofasmallervalvewouldresolvethissituation.RoughMachiningleftintheBodyNeckBoreInMay,1993,NDVhadchangeditsroughmachiningprocesstosetupandroughcuttheneckboreandseatpocketusingthesamesetupmethodandsinglepointtooling-boringasthefinishmachiningprocess.Priortothistimetheneckborewasroughmachinedonaradialdrill.Thisdrillingprocesswasnotalwaysperformedonthesamecenterlineasthefinalmachiningandthedrillhadatendencytotailoffcenter.ThisareahasbeenresolvedasdescribedaboveinMay,1993.RatioGuideLength-DiscDiameterNDV'sdesigncriterialimitsthepotentialdisctilttolessthan1/2'ndrequiresaratioofone(1)orgreaterforthedisc,guidelengthtodiameter.The2"-1878¹PistonCheckdischasaratioof1.12:1.BothNDV'sdesigncriteriaandthe2"-1878¹designarerepresentativeofNDVandcompetitivevalvedesignswhichhavebeenproventobesuccessfulinmostservices.RooCsNDVevaluatedtheasfoundconditionofthepistoncheckvalvethatstuckopen.Toassistinourrootcauseanalysis,weperformedflowtestsontwo(2)2"-1878¹PistonCheckvalves(one(1)valvereturnedfromFP&L,S/NET401-9-6).ReferenceNo.3Report,enclosed,documentsthetaskandresults.Thetestingwasperformedtoevaluatevalveperformanceatvariousforwardflowrates.Thetestconclusionwasthevalvealwaysclosedwhenforwardflowended.
EgAsaresultofourevaluationoftheFPBLfailedvalveandourtesting,wehaveconcludedthattherootcauseisthediscoscillation,causedbythereciprocatingpump,causingfrettingtotakeplaceinthevalvebodydiscguidearea.Thefrettingareaprovidesaconfigurationinthebodyguidethatallowsthedisctostickopenwithoutforwardflowandwithreverseflow.A/DV'srecommendationstoeliminatethevalveoperationalproblemare(preferredlistedfirst):A.Useofin-linecheckvalvesinreciprocatingpumpapplications.Thisvalvedesignprovidesbetterwearresistantmaterialsasdiscguidesthroughouttheentirevalvestroke.~~Useofsmallerpistoncheckvalve(valvesizeorreducedport)inreciprocatingpumpapplicationstomorefullyopenthediscwherebetterbody-discguidingisavailable.AttachedaregraphsofflowrateversusdiscpositionandCvversusdiscpositiontobeusedtoevaluateT-patternpistoncheckvalvesizeselection.WhereasmallerT-patternpistoncheckvalve~producestoohighapressuredrop,useofaY-patternpistoncheckvalvemayresolvethisconcern.T-patternandY-patternpistoncheckvalvesandin-linecheckvalvesarewithinA/DY'sproductlines.AvailabilityofY-patternpistoncheckvalvesissclleduledforthesecondquarterof1997.lffurtherdiscussionisrequiredontheabove,pleasefeelfreetocontactus.ANCHOR/DARLINGVALVECOMPANYFloydA.Bensinger,P.E.Manager-Engineeringbcc:J.ChappellT.JohnsonW.Knecht'G;KneiserR.MaiettaG.ParksJ.TarbuttonH.WescottF.Velez 502"8cSmallerT-PistonCheckValvesFlowCoefficient(Cv)vs.DiscPosition~~FAB01-Nov-9640CEJ030201000%20%40%60%80%100%1/2"PCsO1-1/2"PCsDisc%Open+3/4"Bc1"PCs2"PCs 3502"8cSmaIIetT-PistonCheckVaIvesAirFlowRote(cfm)vs.DiscPosition~~FAB01-Nov-963002502001501005000%20%40%60%80%100%1/2",3/4"8c1"P.CsDisc%Open+1-1/2"PCs<>2"PCs 2602"BcSmallerT-PistonCheckValvesWaterFlowRote(gpm)vs.DiscPosition~~FAB01-Nov-96240220200180160140120.100.8060402000%20%40%60%80%100%1/2",3/4"Bc1"PCsDisc%Open+1-1/2"PCs<>2"PCs PARTCTYNO001IBOOTDESCRIPTION002I004I015IBONNETDISCSEATRINC050IPRESSURESEALCASKET052ISPACERRING054IBOMNETRETAINERSASSI~5MSA47~16SA65IP560TYPEIA276.S21600AGRAPHITEA47~16SA479-516MATERIALREVISIONSDELETEDMOTE5:OYSN,ADDEDMofdseTHRUlo.CUSTOMERNOTEADOEOUNITSAANOVALVEDATASHEETNO.DELETEDCUST.P.o.No.dcMOVEDA/OVS.o.No.TALEBLOCK:DELETED"CLOSEACWIHI2215I256I260I545IBONNETCAPSCREWANTHIOTATIONPINWIRENAMEPLATEA574AISI502(SPRINCTTPEER516AISI504545IIDENTIFICATIONPLATEAISI504429ISPRINGINCONELXI.VALVEISASMECLASSIPER1965ASMKSKCTIOMR2.APPROXVALVEWEIGHT24LBS5.APPROXCV564.PISTONCHECKVALVEDESIGNEDFORMOUMTINCINAHORIZONTALRUNOFPIPEWITHVALVEENDSHORIZONTALANDBONNETONTOP5.VALVEDESICNPRESSUREIS2755PSIAT6doFNOTES7.4-ASMKPRESSUREBOUNDARYPARTd.CRACKIMCPRESSURE5PSI9.ANSI1676STANDARDINTERPOLATEDPRESSURECLASSlo.HYDROSTATICTESTINFORMATION:SHELLSEATPRESSURE(PSI)57754956ALLOWABLKLEAKAGE(CC/HR)03d.MINIMUMFLOWDIAMDER1.500SEATRINGINSIDEDWlETER~1.500DURATION(MIN)10525d~ooo5~FO0)COO!0COCIILOWElO.Vl>COI:IL054215052050002429004001015FLORIDAPOWERRLIGHTCOMPANYST.LUCIEUNITSIR'2SPECIFICATIONNo.:MN5.06VALVEDATASHEKflYDSPSL&IO'Y.~.52MIMFLOWZeo545546df.520MINSECTIONAAET401%ANCHORDARLINGVALVECOMPANY2"-1878FULLPORTSOCKETENDSSTAINLESSSTEELPISTONCHECKVALVENONWOBALTTRIMHIP9AIO00302IT'~l'T~ONBY.'AlQ10I92QI9ll212PS71OAPPO6IIRFBegaIO-IIHI2I2545~76