ASMEB31.1a-2008AddendatoASMEB31.1-2007PowerPipingASMECodeforPressurePiping,B31ANAMERICANNATIONALSTANDARDThreeParkAvenue•NewYork,NY10016A5807ACopyright2008bytheAmericanSocietyofMechanicalEngineers.NoreproductionmaybemadeofthismaterialwithoutwrittenconsentofASME.cCopyrightedmateriallicensedtoStanfordUniversitybyThomsonScientific(www.techstreet.com),downloadedonOct-05-2010byStanfordUniversityUser.Nofurtherreproductionordistributionispermitted.UncontrolledwDateofIssuance:June9,2008ASMEistheregisteredtrademarkofTheAmericanSocietyofMechanicalEngineers.ThiscodeorstandardwasdevelopedunderproceduresaccreditedasmeetingthecriteriaforAmericanNationalStandards.TheStandardsCommitteethatapprovedthecodeorstandardwasbalancedtoassurethatindividualsfromcompetentandconcernedinterestshavehadanopportunitytoparticipate.Theproposedcodeorstandardwasmadeavailableforpublicreviewandcommentthatprovidesanopportunityforadditionalpublicinputfromindustry,academia,regulatoryagencies,andthepublic-at-large.ASMEdoesnot“approve,”“rate,”or“endorse”anyitem,construction,proprietarydevice,oractivity.ASMEdoesnottakeanypositionwithrespecttothevalidityofanypatentrightsassertedinconnectionwithanyitemsmentionedinthisdocument,anddoesnotundertaketoinsureanyoneutilizingastandardagainstliabilityforinfringementofanyapplicableletterspatent,norassumeanysuchliability.Usersofacodeorstandardareexpresslyadvisedthatdeterminationofthevalidityofanysuchpatentrights,andtheriskofinfringementofsuchrights,isentirelytheirownresponsibility.Participationbyfederalagencyrepresentative(s)orperson(s)affiliatedwithindustryisnottobeinterpretedasgovernmentorindustryendorsementofthiscodeorstandard.ASMEacceptsresponsibilityforonlythoseinterpretationsofthisdocumentissuedinaccordancewiththeestablishedASMEproceduresandpolicies,whichprecludestheissuanceofinterpretationsbyindividuals.Nopartofthisdocumentmaybereproducedinanyform,inanelectronicretrievalsystemorotherwise,withoutthepriorwrittenpermissionofthepublisher.TheAmericanSocietyofMec...