Designation:A691/A691M−09(Reapproved2014)StandardSpecificationforCarbonandAlloySteelPipe,Electric-Fusion-WeldedforHigh-PressureServiceatHighTemperatures1ThisstandardisissuedunderthefixeddesignationA691/A691M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecification2coverscarbonandalloysteelpipe,electric-fusion-weldedwithfillermetaladded,fabricatedfrompressure-vessel-qualityplateofseveralanalysesandstrengthlevelsandsuitableforhigh-pressureserviceathightempera-tures.Heattreatmentmayormaynotberequiredtoattainthedesiredmechanicalpropertiesortocomplywithapplicablecoderequirements.Supplementaryrequirementsareprovidedforusewhenadditionaltestingorexaminationisdesired.1.2Thespecificationnominallycoverspipe16in.[400mm]inoutsidediameterandlargerwithwallthicknessesupto3in.[75mm]inclusive.Pipehavingotherdimensionsmaybefurnishedprovideditcomplieswithallotherrequirementsofthisspecification.1.3Severalgradesandclassesofpipeareprovided.1.3.1GradedesignatesthetypeofplateusedaslistedinTable1.1.3.2Classdesignatesthetypeofheattreatmentperformedinthemanufactureofthepipe,whethertheweldisradio-graphicallyexamined,andwhetherthepipehasbeenpressuretestedaslistedin1.3.3.1.3.3Classdesignationsareasfollows(Note1):ClassHeatTreatmentonPipeRadiography,seeSectionPressureTest,seeSection10nonenonenone11none9none12none98.313nonenone8.320stressrelieved,see5.3.1nonenone21stressrelieved,see5.3.19none22stressrelieved,see5.3.198.323stressrelieved,see5.3.1none8.330normalized,see5.3.2nonenone31normalized,see5.3.29none32normalized,see5.3.298.333normalized,see5.3.2none8.340normalizedandtempered,see5.3.3nonenone41normalizedandtempered,see5.3.39none42normalizedandtempered,see5.3.398.343normalizedandtempered,see5.3.3none8.350quenchedandtempered,see5.3.4nonenone51quenchedandtempered,see5.3...
