ASME_B16.1-2020.pdf

AN AM E R IC AN NAT IO NAL STANDARDASME B16.1-2020(Revision of ASME B16.1-2015)Gray Iron PipeFlanges andFlanged FittingsClasses 25,125,and 250ASME B16.1-2020(Revision of ASME B16.1-2015)Gray Iron PipeFlanges andFlanged FittingsxClasses 25,125,and 250AN AMERICAN NATIONAL STANDARDxDate of Issuance:November 9,2020The next edition of this Standard is scheduled for publication in 2025.ASME issues written replies to inquiries concerning interpretations of technical aspects of this Standard.Periodically certainactionsoftheASMEB16CommitteemaybepublishedasCases.CasesandinterpretationsarepublishedontheASMEwebsiteunder the Committee Pages at http:/cstools.asme.org/as they are issued.Errata to codes and standards may be posted on the ASME website under the Committee Pages to provide corrections toincorrectlypublisheditems,ortocorrecttypographicalorgrammaticalerrorsincodesandstandards.Sucherratashallbeusedon the date posted.TheCommitteePagescanbefoundathttp:/cstools.asme.org/.Thereisanoptionavailabletoautomaticallyreceiveane-mailnotification when errata are posted to a particular code or standard.This option can be found on the appropriate CommitteePage after selecting“Errata”in the“Publication Information”section.ASME is the registered trademark of The American Society of Mechanical Engineers.ThiscodeorstandardwasdevelopedunderproceduresaccreditedasmeetingthecriteriaforAmericanNationalStandards.TheStandardsCommitteethatapprovedthecodeorstandardwasbalancedtoassurethatindividualsfromcompetentandconcernedinterestshavehadanopportunityto participate.The proposed codeorstandardwasmadeavailable forpublic reviewandcommentthatprovidesanopportunityfor additional public input from industry,academia,regulatory agencies,and the public-at-large.ASME does not“approve,”“rate,”or“endorse”any item,construction,proprietary device,or activity.ASME does not take any position with respect to the validity of any patent rights asserted in connection with any items mentioned in thisdocument,anddoesnotundertaketoinsureanyoneutilizingastandardagainstliabilityforinfringementofanyapplicableletterspatent,norassumeanysuchliability.Usersofacodeorstandardareexpresslyadvisedthatdeterminationofthevalidityofanysuchpatentrights,andtherisk of infringement of such rights,is entirely their own responsibility.Participation by federal agency representative(s)or person(s)affiliated with industry is not to be interpreted as government or industryendorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued in accordance with the established ASME proceduresand policies,which precludes the issuance of interpretations by individuals.No part of this document may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersTwo Park Avenue,New York,NY 10016-5990Copyright 2020 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword.ivCommittee Roster.viCorrespondence With the B16 Committee.viiSummary of Changes.ixList of Changes in Record Number Order.x1Scope.12General.13PressureTemperature Ratings.24Size.25Marking.26Materials.37Fitting Dimensions and Tolerances.38Bolt,Nut,and Gasket Dimensions.59Hydrostatic Tests.510Certifications.5Mandatory AppendixIReferences.36Nonmandatory AppendixAQuality System Program.37Figures4.2-1Method of Designating Outlets of Reducing Fittings in Specifications.77.9.1-1Drain Connections.347.9.2-1Method of Designating Location of Tapped Holes for Drains When Specified.35Tables3.1-1PressureTemperature Ratings.67.3.2-1Dimensions of Class 25 Gray Iron Flanged Fittings.87.3.2-2Dimensions of Class 125 Gray Iron Flanged Fittings.127.3.2-3Dimensions of Class 250 Gray Iron Flanged Fittings.187.3.2-4Dimensions of Anchorage Bases for Straight and Reducing Class 125 Tees.237.3.2-5Dimensions of Anchorage Bases for Straight and Reducing Class 250 Tees.277.6.1-1Class 25 Flange and Bolting Dimensions.297.6.1-2Class 125 Flange and Bolting Dimensions.307.6.1-3Class 250 Flange and Bolting Dimensions.327.9.1-1Minimum Thread Length.34iiiFOREWORDIn1894,theAmericanSocietyofMechanicalEngineers(ASME)adoptedastandardflangetemplate(“ASMEStandard”)forlow-pressureservice.A“ManufacturersStandard”forpressuresupto250psifollowedin1901.Around1910,agroupoffittings manufacturersformed an organizationthat wasthe forerunnerof thepresent Manufacturers StandardizationSocietyoftheValveandFittingsIndustry(MSS)andundertookthedesignofalineofflangedfittings.Adocumentcoveringthis work was published in 1912.During the years 1912 through 1914,a Joint Committee of the ASME and the Manufacturers Committee formulatedcompromisestandarddimensionsforpipeflangesandflangedfittingsforuseundersaturatedsteampressuresof125psiand 250 psi pressure ranges.The Joint Committees report was accepted at a conference attended by representatives ofASME,the Manufacturers Committee,the U.S.government,and