1、ASME B16.25-2003(Revision of ASME B16.25-1997)BUTTWELDINGENDSAN AMERICAN NATIONAL STANDARD金The American Society ofMechanical EngineersThree Park Avenue New York,NY 10016No roproduction or natworking permitled without liconso from IHSNot for RosaleFOREWORDIn July 1953,the American Welding Society pre
2、sented a proposal on Welding End Preparationto Sectional Committee B16 of the American Standards Association(ASA),with the recommenda-tion that it be considered as a candidate American Standard.The proposal was expanded toinclude welding preparation for flanges and valves covered by ASA B16.5,Steel
3、Pipe Flangesand Flanged Fittings,and for fittings covered by ASA B16.9,Buttwelding Fittings.Considerationwas also given to Pipe Fabrication Institute Standard ES-1.The third draft reviewed by Subcommittee 3,Subgroup 6(now Subcommittee F)of the B16Sectional Committee was forwarded to the Committee,to
4、 the cosponsor organizations,and thento ASA for approval.Final approval was given on September 14,1955,with the designation ASAB16.25-1955.Revisions were developed as need for clarification and improvement became known,and wereapproved as ASA B16.25-1958 and ASA B16.25-1964.After ASA reorganized as
5、the AmericanNational Standards Institute(ANSI)and the Sectional Committee became American NationalStandards Committee B16,a further revision was approved as ANSI B16.25-1972.Subcommittee F immediately began work on a major expansion and updating of the standard,adding illustrations and requirements
6、for welding end configurations applicable to a number ofspecific circumstances,including cast steel and alloy valves.When a draft had been developed thatovercame the many problems and conflicting demands,the Standards Committee,cosecretariatorganizations,and ANSI concurred in approval of ANSI B16.25
7、-1979 on July 18,1979.In 1982,American National Standards Committee B16 was reorganized as an ASME Committeeoperating under procedures accredited by ANSI.In the 1986 edition,inch dimensions wereestablished as the standard and numerous changes in text and format were made.Notes forillustrations were
8、also clarified.Following approval by the Standards Committee and ASME,approval as American National Standard was given by ANSI on October 8,1986,with the newdesignation ASME/ANSI B16.25-1986.In 1992,the subcommittee revised the requirements for the preparation of the inside diameterof welding end.Th
9、e references in Annex B were also updated.After public review and approvalby ASME,this edition was approved by ANSI on October 26,1992,with the new designationASME B16.25-1992.In the 1997 Edition,metric dimensions were added as an independent but equal standard tothe inch units.An Annex was also add
10、ed to reference quality system requirements.Followingapproval by the Standards Committee and ASME,this revision to the 1992 edition of B16.25 wasapproved as an American National Standard by ANSI on April 17,1997,with the new designationASME B16.25-1997.In this 2003 Edition,the reference standard dat
11、es were updated.There were clarifications totext made to address inquiries.Tolerances on bevel angles were modified slightly.Followingapproval by the Standards Committee and ASME,this revision of the 1997 edition of B16.25 wasapproved as an American National Standard by ANSI on December 17,2003,with
12、 the newdesignation ASME B16.25-2003.Requests for interpretation or suggestions for revision should be sent to the Secretary,B16Committee,The American Society of Mechanical Engineers,Three Park Avenue,New York,NY10016-5990.ivse with ASMENo roproduction or notworking permitled without liconso from IHSNot for Rosale