管道施工规范(asmi) 18页

'CONTENTSPAGE1.GENERAL1.1Scope31.2SpecificJobRequirements31.3CodesandStandards31.4RelatedEngineeringSpecifications31.5Units32.GENERALREQUIREMENT2.1Qualification42.2Material43.FABRICATION3.1General53.2Cutting53.3EndPreparation63.4AlignmentandTrimming73.5GeneralRequirementforWelding113.6WeldingRods113.7Welding123.8Marking203.9Storing204.ASSEMBLINGANDERECTION4.1General214.2FlangedJoint224.3ThreadedJoint224.4MechanicalJoint226.INSPECTION,EXAMINATIONANDTESTING6.1ExtentofInspection,ExaminationandTesting6.2Non-DestructiveExamination287.PRESSURETESTING-PROCESS8.COATONGANDWRAPPINGOFPIPING9.CLEANINGAFTERPIPINGASSEMBLINGANDERECTION31 1.GENERAL1.1ScopeThisprocedurecoversthegeneralrequirementsforthepipingconstructionwork,includingtestandinspectionofplanttobecarriedoutbyChinaNationalChemicalEngineerNO.7ConstructionCompanyLtd(hereinafterreferredtoasCC-7).1.2SpecificJobRequirementsSpecificjobrequirementswhichareattachedtothisprocedurecovermodificationstothisspecification,Customer’sspecialorlocalrequirementsaswellasspecificjobdatapertinenttothisspecification.WhereSpecificJobRequirementsareincontradictiontothisspecification,SpecificJobRequirementsshallgovern.1.3CodesandStandardsInternationalcodesandstandardssupplementaryinrelatedtothisspecificationshallbeasfollows:(1)ASMEB31.3ProcessPiping(2)ANSI/ASMEB1.20.1PipeThreads,GeneralPurpose(Inch)(3)ASME/ANSIB16.5PipeFlangesandFlangedFittings(4)ASMEBoilerandPressureVesselCode,SectionV(5)SectionIIpartCMaterialSpecifications-WeldingRods,ElectrodesandFillerMetals(6)SectionIXQualificationStandardforWeldingandBrazingProcedures,Welders,Brazers,andWeldingandBrazingoperators1.4RelatedEngineeringSpecificationsTherelatedBASF-YPCCompanyLtd.Specificationtosupplementthisspecificationareasfollows:(1)RPI94/1GeneralRequirementsforBASFTechnologyProjects(2)40-010-00-0-0-00-003PositiveMaterialIdentification(3)50-010-00-0-0-00-003PipingMaterialSpecification(4)50-010-00-0-0-00-004SteamTracing&Winterization(5)50-010-00-0-0-00-006PipingIdentificationSystem(6)50-010-00-0-0-00-009PressureTesting-Process&UtilityPiping(7)50-010-00-0-0-00-024WeldingandNon-DestructiveExaminationsofPipingSystems(8)50-010-00-0-0-00-025ShopandFieldFabrication,InstallationandHandling-ProcessandutilityPiping(9)50-010-00-0-0-00-034PipeSupport1.5UnitsTheAA/AEUnitshallbeappliedasthemeasurementsystemfordocumentsanddrawings.NominalsizeofpipingcomponentsshallbemeasuredinInches,forwhichtheabbreviationisNPS.Nominalflangeratingshallbeaspertheappliedcodesandstandards.2.GENERALREQUIREMENT2.1Qualification(1)PersonswhoareengagedforweldingincludingtackweldingandsupportweldingworkshallhavepassedtheweldingperformancequalificationtestbeforecommencementofweldingworksandshallbeperformedinaccordancewithASMEB31.3para.328. (2)WeldingProcedureSpecificationandtheProcedureQualificationRecordshallbeapprovedbyTECandownerbeforecommencementofweldingwork.Productionweldingshallnotcommencebeforereceiptofwrittenapprovalandauthorizationtostartwelding.(3)Personswhoareengagedforpipe-fitting,assembling,erectionwork,shallbefullytrainedandshallhavethequalificationofEmployer.License,certificate,passorqualificationissuedfromAuthorities,ifavailable,shallbeeffective.(4)TheinspectornominatedforthejobmustbeaspecialistoranexpertinrespectiveexaminationsandlicensedorqualifiedbyaninternationallyrecognizedAssociationand/orbyanystatutoryrequirementapplicable.2.2Material2.2.1PipingMaterialsshallbeinaccordancewithDOC.No.50.010.AA.0.0.00.5012.2.2ItisapplicabletouseotheralternatematerialswhichshallbeapprovedbyTECandowner.2.2.3SelectionofweldingrodshallbeinaccordancewithWeldingProcedureQualificationtestRecord(PQR)unlessotherwiseapprovedbyTECandowner.2.2.4Qualitycertificateoftechnicalgastobeusedfortheworksuchasargongas,propanegas,etc.shallbeprovidedwithapprovalofTECbeforeworkstarts.3.FABRICATION3.1General3.1.1FabricationrequirementshallbeinaccordancewithASMEB31.3unlessotherwisespecified.3.1.2FabricationshallbeexecutedinaccordancewiththerelatedEngineeringSpecificationandthedrawings,documentstatedinPar.1.4and2.3ofthisspecification.3.1.3Theboltholesofflangesshallbelocatedsymmetricallyfromaverticalcenterlineinahorizontalpipeline,andfromplantnorthinaverticalpipelineunlessotherwiseindicatedinthedrawing.3.1.4MarkingofpipingmaterialsshallbeinaccordancewithPara.10,0inDoc.No.50.010.00.0.0.00.0253.2Cutting3.2.1Cuttinglineshallbemarkedonpipe.Wherethematerialmarkingwillbecomeinvisibleaftercutting,additionalmaterialmarkingshallbeprovided.3.2.2Inthecaseofgascutting,cuttingsurfaceshallbegroundofftoremoveanyedgeandroughnessandbemadeflushandsmoothsoasnottoharmweldingquality.3.2.3Inthecaseofgascutting,cuttingslugstickedinsidepipeshallbecompletelyremoved,especiallyforboringofpipeforweldbranch.3.3EndPreparation3.3.1EndpreparationforbuttweldshallbeinaccordancewithTable3.3.1,oranyotherwhichmeetstheWPS.(1)WeldingBevelsforButtWelds Table3.3.1Unit:mmThicknessofPipeTypeofEndShapeofGroovett<3It37.5±2.5°1.6±0.8t£22Vt>22Double-V10±2.5°1.6±0.819±2t37.5±2.5°(2)ShapeofbevelingotherthanmentionedinTable3.3.1shallbeinaccordancewiththeWPSapprovedbyTECandowner..3.4AlignmentandTrimming3.4.1Rootgapforbutt-weldshallbeinaccordancewiththeWPS.3.4.2Inthecaseofbuttweldingpipeand/orfittinghavingunequalwallthickness,ofwhichthedifferenceismorethan3mminoutersurfaceand/or1.5mmininnersurface,theendofthethickerpipeshallbetrimmedbygrindingaspertheFig.3.4.2(a),(b)and(c)shownbelow.Thegradientofthistrimmingshallbelessthan30betweenworkedandunworkedpartsshownasbelow.Unit:mmOver2or0.5xtm(a)WhicheverislesswhichwhicheverislessMax.30°³tm1.5orOver³tmMax.30°(b) 1.5orOvertmorOverIncaseultrasonictesttobeappliedMax.30°³tm(c)tm:requiredminimumwallthicknessofpipe.Fig.3.4.2Note:Inthecasethat“SpecialEndDetail”isspecifiedintheSpecificationH-103forthepipeand/orfittingofwhichthenominalwallthicknessis30mmandover,theendpreparationshallbeinaccordancewithsuchprovision.3.4.3BranchconnectionswhichabuttheoutsidesurfaceoftherunpipeshallbecontouredforgrooveweldswhichmeettheWPSrequirements[seeFig.3.4.3(a)and(b)].Branchconnectionwhichareinsertedthrougharunopeningshallbeinsertedatleastasfarastheinsidesurfaceoftherunpipeatallpoints[seeFig.3.4.3(c)].gmmgg0mm-3mm(a)(b)(c)_Tb_Tb_Tbg=RootgapperWPS_m=Thelesserof3.2mmor0.5TbFig.3.4.33.4.4Whenapipehavingalongitudinalweldseamisusedinahorizontalline,thepipeshallbelaidsothatthelongitudinalweldseamisnotonbottomortopofthepipe.(Theseshouldbelocatedatleast45ofromthebottomsofthepipe).Allocationandrelationamongcircumferential,longitudinalandother(branch,support,etc.)weldsareshownintheFig.3.4.4(a),(b)or(c).(1)Circumferentialjoint L1L2L1C.LC.LNote:L1≥100mmL2≥50mmor6xTwwhichisgreaterTw:PipeWallthicknessFig.3.4.4(a)(2)BranchpipeandweldlineonrunpipeLLL1Fig.3.4.4(b)Notes:1.LandL1showthedistancebetweenbothtoesofthebead.2.Lshallbethreetimesthepipethicknessorover.3.L1shallbemorethan100mm.(3)Support/ShoeandweldseamofmainpipeDetail“A” “A”Whenasupportisweldedtoabendorpipe,theweldshallnotcrosstheweldofthebendorpipe.Bothsidesshallberoundlywelded.LLWeldingSupportWeldingShoeLLNote:Lshallbeminimum6mm.Fig.3.4.4(c)“A””3.6GeneralRequirementforWelding3.6.1Requirementandcriteriaforweldingshallbeasfollows,unlessotherwisespecifiedinthedrawings:(1)WeldingshallbeperformedinaccordancewithWPS.(2)Weldingshallnotbecarriedoutinadverseweatherconditionswherethereisimpingementofrain,snow,sleetstormorexcessivewindattheworkingarea,unlessappropriateandadequateprotectionisprovided.(3)Thelevelshallbefullycleanedsothatthereisnorust,oil,paint,sand,moisture,etc.remaining.Whereabevelisnottobeweldedimmediatelyitshallbeprotectedtopreventcontamination.(4)Allslag,weldspatterandfluxremainingonanybeadofweldingshallberemovedbeforethenextbeadisdeposited.(5)Spatter,slag,etc.ontheweldorintheheataffectedzone,shallbethoroughlyremovedtothemetalsurface.(6)Arcstrikesonbasemetalshallbeavoidedatalltimes.Arcstrikeshallbegroundflushandliquidpenetranttested.Anydefectshallbegroundoutandweldrepaired.(7)Materialofwirebrushshallbeproperlyselectedforworkingcarbonsteelrespectively.Theyshallalwaysbekeptseparateandneverusedonanythingotherthanthedesignation.(8)Weldingforaweldedjointvalveshallbecarriedoutwiththevalveopened.(9)Weldinternalprotrusionattheweldneckjointofanorificeflange,shallberemovedflushandsmoothwithagrinder.Anyconcavityintheroot,shallbeweldrepairedandgroundflushandsmooth. (10)Allweldsincludingsocketweldingshallbeperformedatleast2layersweldandendpointofweldateachlayershallbechanged(stagger).(11)Weldingofdissimilarmetalsshallbecarriedoutatfabricationshopifpossible.3.7WeldingRods3.7.1BrandnameofweldingrodtobeusedatshopandsiteshallbeapprovedbyTECandownerbeforeworkstartsandthatshallbeusedonly.3.7.2Eachweldershallbeimmedatoryprovidedwithaportabledryertoshop/Fieldworkafterwithdrowelectrodefrommainovencontainer.3.7.3BakingandHoldingtemperatureofelectrodeshallbeperformedwithmanufacture’srecommendation.3.8Welding3.8.1Tackweldingshallbecarriedoutasfollows:(1)Bothrootandbridgetackweldingmethodmaybeapplied.(2)Avoidwrongfit-upwhichwouldcauseresidualstress.(3)KeepthecorrectrootgapbyusingspacersaccordingtoWPS.(4)WeldingconditionoftackweldingshallbeinaccordancewithWPS.(5)Providesufficientexternalpipeclampsorinternalspidersforsettingup.(6)Ensurethecontactsurfaceoftheclampsorspidersaremadeofthesamebasemetal,oraninertcompound.(7)Bridgetackshallneverbehammeredoff.Bridgetacksshallberemovedbygrindingorgascutting.Gascuttingshallonlybeperformedattheupperpartoftheweldtoeandflushsurfaceofbasemetalbygrinding,andthenaliquidpenetrantexaminationshallbecarriedout.Anydefectshallbegroundoutandweldrepaired.3.8.2Buttjointweldingofpipesshallbeperformedasfollows:(1)WeldingshallbeperformedinaccordancewithWPS.(2)CircumferentialbuttweldingshallbeperformedwithouttheuseofabackingringunlessspecifiedinWPS.(3)Beforeweldingoftheroot,bothendsoftheroottackweldbeadshallbepreparedwithagrinderasshowninthefollowingillustrationinordertomakecompletefusion. L1:Max15mmforNPS£24”Max40mmforNPS>24”Fig.3.8.23.8.3BranchconnectionsshallbemadebyusingthefittingsasspecifiedintheDoc.No.50.010.AA.0.0.00.501.However,wherethebranchistobeweldeddirectlytothemainruninaccordancewithDoc.No.50.010.AA.0.0.00.501.orPipingArrangementDrawing,weldingshallbeperformed,unlessotherwisespecified,showninfollowingFig.3.8.3: Tm*_Th³6mm_0.5Tr_ThThesurfaceoftheweldmetalshallbefinishedflushbygrindingordrilling.³2NPS£11/2NPS³3mmTmBranchPipeSize*:SpecifiedasperWPS_Th_Th_Tb_Th_Th_Tb_Tb_Tb_Tb(2)(1)(3)(4)(5)Outlet@Atc*_Tr3-5fVenthole>45°tc*_0.5Tr3-5fVenthole@A_Trtc*Unit:mm*tc>45°45°35°1.6-3.2Fig.3.8.3Notes:1.Throatthickness“tc”shallbeof0.7Tb(minimum6.4mm). 2.Thesymbolsusedinthesefiguresareasfollows:_Th:nominalthicknessofrunpipe_Tb:nominalthicknessofbranchpipe_Tr:nominalthicknessofreinforcementpad3.Atfirst,weldpartandpreparetheweldsurfacewithagrinder,thenweldthepart.4.Wherereinforcementisnecessary,itisindicatedinthePipingArrangementDrawingandNotesforPipingDrawings.3.8.4Filletweldingofpipetoslip-onandsocketweldflangesshallbeperformedasshowninfollowingFig.1.4Tmin.Fig.3.8.4Unit:mmconcentricallyset1.4Tmin.Anyweldmetalintotheboreofthepipeshallberemovedbygrindingorfilingtomakeitflushwiththeinsidediameter.1.4Tmin.3.01.4Tmin.TTt(a)Slip-on(b)Slip-onT1.6-3.2t(c)SocketWeld1.4Tmin.3.01.4Tmin.TTNotes:1.T:thicknessofpipet:thicknessofflangehub2.If1.4Tislargerthant,tshallbetaken.3.8.5SocketweldingofpipecomponentsotherthanflangesshallbeperformedasshowninfollowingFig.3.8.5: Fig.3.8.5T=nominalwallthickness1.6-3.2cxTcx(min.)=1.25Tbutnotlessthan3.2mmUnit:mmcx3.11Marking3.11.1Allpipingcomponentsforwhichweldinghasbeencompletedshallbearthepaintedmarkingwiththeidentificationsymbolofthewelderasconfirmation.3.11.2SpoolpieceNo.shallbeclearlymarkedonfabricatedcomponents.3.12StoringInsideoffabricatedcomponentsshallbecleanedbyairblowing,thenopeningsoffabricatedcomponentsshallbecoveredwithsuitablematerialssoasnottoentertheforeignmatterssuchassand,mad,etc.intopipingcomponents.Gasketsurfaceofflange,thread,weldingbevelshallbeprotectedfromanydamageduetocleaningworkandhandlingofstoring.4.ASSEMBLINGANDERECTION4.1General4.1.1Beforeassemblingofpiping,actualtolerancecausingfromfoundation,steelstructure,equipmentinstallationworkshallbeconsideredforthepipingassemblingwork.4.1.2Excessivestressshallnotbeallowedtothenozzlesofrotatingmachinewhentheflangeoffabricatedcomponentisconnected,suchworkshallbecarriedoutinthepresenceofpersoninchargeofthemechanicalwork.Andopeningssuchasflangedjointsofapump,compressor,etc.shallbekeptcoveredwiththinmetalplateorothersolidblindswithahandletopreventdustand/orforeignmaterialfromenteringintothemachine.4.1.3Ifhotworktobeperformedinthevicinityofinstrumentcontrolorpowercableduct,anadequateprotectivecovershallbeprovidedinadvancesoasnottodamagethecables.4.1.4Whenworkiscarriedoutinthevicinityofpipingmadeof,orlinedwithspecialmaterialssuchasplastics,rubber,glass,etc.,careshallbetakensoasnottodamagethem.4.1.5Valvesshallbeassembledincleancondition,theyshallnotbeopenedduringpipingerectionexceptthatweldingandheattreatmentofaweldedvalvejointshallbecarriedoutwithvalveopened.4.1.6Ifcutting,makingofholestotheassembledpipingandsuchkindofworkiscarriedoutatassembledplaceduetothereasonofmodification,improvement,etc.,cutpieceandforeignmaterialsshallberemovedfrominsideofpipinganditshallbeconfirmedthattheinsideofpipingiscleaned. 4.1.7Valveshavingflowdirectionshallbeinstalledtoconformtheflowdirectioninaccordancewithpipingdrawings.Careshallbetakentothevalvesincasevalveflowdirectionisreversedagainsttheflowdirectionofpipeline.4.1.8Itisprohibitedtousesmallsizepiping,pumps,instrumentetc.asscaffoldingorworkingstage.4.1.9Thefollowingrequirementshallbeobservedforpipingsupport.(1)PipesupportsshallbefabricatedandinstalledinaccordancewithPipeHangingDetails.(2)Asarulethelocationofpipe-supportsshallbeinaccordancewiththePipingArrangementDrawingandHook-upDrawing.(3)Thepre-settingpiecesofthepipehangershallberemovedaftercompletionofleaktestofthepipeline.However,pipelineswhichwillbeinsulated,itshallberemovedaftercompletionoftheinsulationwork.(4)Ashoesupportshallbeattachedtothepipeinaccordancewiththedrawings.Itisnotpermittedtotack-weldashoesupporttothepiperack,wheretheshoesupportisnottobepermanentlyfixedtothepiperack.(5)Whensupportsareinstalledonbuildingorsuchkindofstructure,permissionofinstallationshallbegivenbyTECbeforeinstallation.4.2FlangedJoint4.2.1Anydamagetothegasketseatingsurfacewhichwouldpreventgasketseatingshallberepaired,ortheflangeshallbereplaced.4.2.2Flangedjointsshallbeboltedup,aftercheckingthealignmentoftheflangecentersandtheparallelnessofflangefaces,toensurethatthecontactfacesbearuniformallyonthegasket.Bolting-upshallensurethatbolttensionisspreaduniformlyaroundtheflange.4.2.3Particularcareshallbeexercisedtoensurethatallbolt,nutandgasketarecorrectlyinstalledinaccordancewiththerequirementsofDOC.No.50.010.A.A.0.0.00.501.4.2.4Whenassemblingflangeconnections,pasteshallbeappliedtothegasketandbolts.Thesepreventseizureofnutsandadherenceofgaskets.ReferenceofpastesandtheirapplicationsshallbeinSpecificJobRequirement.4.3ThreadedJoint4.3.1ThestandardtobeappliedtoallthreadsshallbeANSI/ASMEB1.20.1PipeThreads(NPT).4.3.2Lubricantshallberemovedcompletelyfromthethreadandinsideofpipeafterthreading.4.3.3Inathreadedjointbetweenpipeandflange,thelengthofthreadonthepipeshallbesuchthattheendofthepipeisshortofthegasketsurfaceontheflangeby1.5to3.0mmwhenscrewed-in.4.3.4Threadshallbejointedwithfullcouplingbetweenstraightpipes,andpipingshallhaveunionjointsinconsiderationwithrepairingatleaktest.4.3.5Threadedjointsshallbesealedwithtapeorthreadingcompound,unlessthereisrestrictionfromprocessrequirement.4.3.6Sealweldingofthreadedparts,ifspecified,shallbeperformedafterthepartisscrewed-incompletelywithoutusingpasteoroilandfullycleaned,decreasedanddriedout.Reinforcementofthesealweldbeadshallcovercompletelytheremainingthreadandmustbeatleast2-layersweldusingasuitablesizeofelectrode.4.4MechanicalJoint 4.4.1MechanicalJointotherthanflangedjointandthreadedjointshallbeinaccordancewithmanufacturer’sinstructionordrawing.4.4.2Careshallbetakentoavoiddistortingthesheetwhenincorporatingsuchjointintopipingassembliesbywelding.6.INSPECTION,EXAMINATIONANDTESTING6.1ExtentofInspection,ExaminationandTestingPrior,duringandaftercompletionoftheworks,thefollowingexaminationandtestsshallbeperformed:6.1.1In-ProcessInspection(1)PriortoCommencementofWorkExaminationandTestingAcceptanceCriterion(a)MaterialcheckTosatisfytherequirementofDocNo.50.010.AA.0.0.00.501(b)WeldingProcedureSpecificationToapprovedbyTECandOwner(c)Welder’sperformancequalificationEachweldershallbequalifiedbyTECandOwneraccordingtoASMEsecIX(d)ElectrodeandweldingconsumableMaterialcertificate(materialname,brand).Tosatisfyapplicablecodesandstandards.(2)PriortoWeldingExaminationandTestingAcceptanceCriterion(a)EndpreparationShapeanddimensionTosatisfytherequirementsofPar.3.4ofthisspecification.CleanlinessTobefreefrompaint,oil,rust,scaleorotherforeignmaterial.(b)TackweldRootopening(Gap)TobewithinthetolerancespecifiedinWPS.Alignment(Mismatch)Misalignmentisnotmorethan1.5mmforinternalsurfaceand2.0mmor0.5xTwwhichissmallerforoutersurface.(c)PreheatingPrePreheatingtemperatureToTokeepthePreheatingtemperaturewithinthetoletolerancespecifiedinTable3.5.2,Para.3.5.3andWSWPS(d)ElectrodeBakingtemperatureToTobeinaccordancewithmanufacturer’sstandard.Bakingtime-di--ditto-DryHoldingtemperature-ditto-Portableoventemperature-ditto-,toprovideforeachwelder (3)AfterWeldingExaminationandTestingAcceptanceCriterionVisualexaminationofCrackNoneweldUndercutGirthweldandBranchconnectionLesser1.0mmor0.25t..Overlap(Coldlap)Lessthan1.0mmThroatthicknessoffilletweldOver0.9t(Half/FullCupling)Over1.0t(SO/SWFlange)(t:thinnerpipethickness)Weldreinforcementorinternalweldprotrusion(RootPenetration)WallThickness6.4orunderover6.4upto12.7over12.7upto25.4over25.4Max.(mm)1.63.24.04.8WeldscarsfromjigsandarcstrikesNovisibledefectLackoffusion.GirthweldandBranchconnectionNoneIncompletepenetration.GirthweldandBranchconnectionNoneSurfaceporosityNone(4)AfterCompletionofWorkExaminationandTestingAcceptanceCriterion(a)VisualcheckNoextradistortion.(b)Hydrostaticand/orpneumaticleaktestAccordingtoPressureTestProcedureandnoleakshallbeacceptable.(c)Holidaytest6.1.2REPAIRWELDING(1)Norepairsbyweldingfromtheoutsideareallowedforthefollowingconditions:·excessivepenetration·excessiveburn-through(2)Rootdefectsoninaccessiblejointsshallbecut-outandrewelded,unlessotherwiseagreeduponwithWeldingEngineering.(3)Priortorepair,causeofthewelddefectshouldbeestablished.Allcracks,non-fusion,lackofpenetration,excessiveslagorporosity,beyondtherequirements,shallberemovedbygougingand/orgrinding.Completeremovalofadefectshallbeverifiedbymagneticparticleorliquidpenetrantexamination.Re-weldingshallbedoneperapplicableapprovedrepairweldingprocedure.Thenumberofrepairsatthesamelocationonaspecificweldshallbelimitedtotwotimes.(4)Allrepairsshallcomplywithcoderequirementsandshallbere-examinedinaccordancewiththerequirementsofthisspecificationwhencompleted.(5)Repairweldingofbasemetaldefectsisnotallowedpriortoapprovaloftheprocedureforthistype ofrepairsandtheextentofNDEafterrepair.6.2Non-DestructiveExamination6.2.1TheweldjointsofpipingshallbeexaminedtotheextentspecifiedinNDEindexwiththefollowingrandomexaminationprocedure:(1)Theexaminationmadeatrandomshallconsistofexaminingnotlessthanoneproductionweldjointselectedfromeachproductionweldjointlotmadebythesamewelderorweldingoperatordefinedasfollows.Theaboveeachproductionweldjointlotmeans;each20productionweldjointsorlessfor5%randomexamination.(2)Theexaminationshallbeappliedtotheentirelengthofweldoftheselectedjoint.(3)Theweldjointsbetweendissimilarmaterialsshallbeexaminedbythemethodusedforthematerialrequiringthemorestringentexamination.6.2.2Whenarandomorspotexaminationofweldjointsrevealsadefect,theprogressiveexaminationforthesamelotdefinedinPar.6.2.1shallbecarriedoutasperthefollowingprocedure.(1)Twoadditionalweldjointsofthesamelot,bythesameweldershallbegiventhesametypeofexamination;and(2)Iftheweldjointsexaminedasrequiredby(1)aboveareacceptable,allitemsrepresentedbythisadditionalexaminationshallbeaccepted;but(3)Ifanyoftheitemsexaminedasrequiredby(1)aboverevealsadefect,twofurtherweldjointsofthesamelotbythesameweldershallbeexaminedforeachdefectiveitemfoundbythatexamination;and(4)Ifalltheitemsexaminedasrequiredby(3)aboveareacceptable,allitemsrepresentedbythisadditionalexaminationshallbeaccepted;but(5)Ifanyoftheitemsexaminedasrequiredby(3)aboverevealsadefect,allitemsrepresentedbytherandomexaminationsshallbefullyexaminedandrepairedorreplacedasnecessarytomeettherequirementofthisspecification.(6)Thedefectiveitem(s)revealedduringprogressiveexamination,shallberepairedorreplacedandreexaminedataboveeachstepasspecifiedinPar.6.1.2.6.2.3Therequirementforradiographicexaminationshallasfollows:(1)RadiographicexaminationofbuttweldsshallbeinaccordancewithASMEB31.3para.344.5.(2)Allbuttweldsbetweenexistinglinesandnewtie-inlinesshallbe100%radiographed.(3)Atleastthespecifiedpercentageofthenumberofweldsmadebyeachweldershallberadiographedaroundtheirtotalcircumference.Ifaweldermakeslessthan10welds,twooftheseshallbefullyradiographed.(4)Thefirstthreeweldsofeachweldershallhave100%radiographyregardlessofpipediameterandwallthickness.Thisevaluationshallbemadeonacommonsizeifpossibleandshallbeperformedasquicklyaspossibleuponcompletionoftheweld. (1)Acceptanceofwelddefectsforbothrandom(limited)and100%radiographyshallbeinaccordancewithASMEB31.3para.341.3.2.However,incompleterootpenetrationsarenotallowed.(2)UseImageQualityIndicators(IQI)shallbeofthewiretypeinaccordancewithIIW/IIS62-60,orunlessotherwiseapprovedbyTECandOwner.(3)Onlyleadscreensmaybeused.(4)Thegamma-raytechniquemaybeusedwhenprioragreeduponinwritingwiththeAuthorizedInspector.Whenthegamma-raytechniqueisagreedupononlyveryfinegrainfilmsequaltoASTM-E94,type1(suchasAGFA-D4)shallbeused.TheapplicationofCo-60sourceshallbeavoided.(5)Wherenecessarytoachievetherequiredminimumfilmsensitivity(imagequality),theradiationsourceshallbeplacedinsidethepipe(singlewalltechnique).(6)Inradiographingacontinuouslengthofweld,theseparateradiographsshalloverlapsufficiently(minimum10mm).(7)Arecordshallbekeptofthequalityandextentofeachwlder’swork.Examinationresultsof100%radiographedPipeclassesandoflimited/randomradiographedPipeclassesshallberecordedseparately.Resultsof100%radiographyarenotvalidfortheminimumextentoflimitedexaminationperwelder.(8)TheNDEContractorisfullyresponsibletomeetthelocalrequirementsforradioactive,radiationsafety.(9)FilmsofrepairweldswillgetthesamefilmnumberastheoriginalfilmswiththeadditionofsuffixZforthefirstrepair;Yforthesecondrepair.ForfieldweldingfilmnumbersuffixesR1andR2shallbeused.(16)PriortoissuetotheauthorizedInspector,allradiographsmusthavebeenreviewed(andresultsofreviewrecorded)bytheContractor’squalifiedinspector.(17)Alloriginalradiographes,includingthoseofrepairedwelds,shallbepresentedtotheauthorizedInspectorforExamination,togetherwithcompletefilledoutexposurereports.(18)Alldefectsrepairedbywelding(otherthannon-pressureattachments)whicharepreviouslyradiographed,shallbere-radiographedafterrepairinaccordancewiththisspecification.(19)ThefollowingdetailofradiographicexaminationshallbespecifiedbyNDEcontractorandshallbeapprovedbyTECandowner.a.Filmtypeandsizeforeachpipesizeandthickness.b.Exposuretechniqueforeachpipesizeandthickness.c.NosofFilmforeachpipesizeandthickness.d.Typeandmaterialofthepenetrometerforeachmaterial,pipesizeandthickness.e.Typeofsourceforeachpipesizeandthickness.6.2.4Requirementforliquidpenetrantandmagneticexaminationparticleexaminationshallbeasfollows:(1)LiquidpenetrantexaminationandMagneticParticleexaminationshallbeinaccordancewithASMEB31.3para.344.3. (2)ProcedureforrandomexaminationshallbeinaccordancewithNDEIndex.(3)OnlytheYokeTechniquewithwetparticleofmagneticparticleexaminationshallbeperformed.7.PRESSURETESTING-PROCESS8.COATONGANDWRAPPINGOFPIPING9.CLEANINGAFTERPIPINGASSEMBLINGANDERECTIONCleaningworkafterpipingassemblinganderectionshallbeperformedasrequiredbyTEC.'