Designation:D2992−18AnAmericanNationalStandardStandardPracticeforObtainingHydrostaticorPressureDesignBasisfor“Fiberglass”(Glass-Fiber-ReinforcedThermosetting-Resin)PipeandFittings1ThisstandardisissuedunderthefixeddesignationD2992;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticeestablishestwoprocedures,ProcedureA(cyclic)andProcedureB(static),forobtainingahydrostaticdesignbasis(HDB)orapressuredesignbasis(PDB)forfiberglasspipingproducts,byevaluatingstrength-regressiondataderivedfromtestingpipeorfittings,orboth,ofthesamematerialsandconstruction,eitherseparatelyorinassemblies.Bothglass-fiber-reinforcedthermosetting-resinpipe(RTRP)andglass-fiber-reinforcedpolymermortarpipe(RPMP)arefiberglasspipe.NOTE1—Forthepurposesofthisstandard,polymerdoesnotincludenaturalpolymers.1.2ThispracticecanbeusedfortheHDBdeterminationforfiberglasspipewheretheratioofoutsidediametertowallthicknessis10:1ormore.NOTE2—Thislimitation,basedonthin-wallpipedesigntheory,servesfurthertolimittheapplicationofthispracticetointernalpressureswhich,bythehoop-stressequation,areapproximately20%ofthederivedhydrostaticdesignstress(HDS).Forexample,ifHDSis5000psi(34500kPa),thepipeislimitedtoabout1000-psig(6900-kPa)internalpressure,regardlessofdiameter.1.3ThispracticeprovidesaPDBforcomplex-shapedprod-uctsorsystemswherecomplexstressfieldsseriouslyinhibittheuseofhoopstress.1.4Specimenendclosuresintheunderlyingtestmethodsmaybeeitherrestrainedorfree,leadingtocertainlimitations.1.4.1RestrainedEnds—Specimensarestressedbyinternalpressureonlyinthehoopdirection,andtheHDBisapplicableforstressesdevelopedonlyinthehoopdirection.1.4.2FreeEnds—Specimensarestressedbyinternalpres-sureinbothhoopandlongitudinaldirections,suchthatthehoopstressistwiceaslargeasthelongitudinalstress.Thispracticemaynotbe...
