1、AN AM E R IC AN NAT IO NAL STANDARDASME B16.3-2021(Revision of ASME B16.3-2016)Malleable IronThreaded FittingsClasses 150 and 300ASME B16.3-2021(Revision of ASME B16.3-2016)Malleable IronThreaded FittingsxClasses 150 and 300AN AMERICAN NATIONAL STANDARDTwo Park Avenue New York,NY 10016 USAxDate of I
2、ssuance:January 17,2022The next edition of this Standard is scheduled for publication in 2026.ASME issues written replies to inquiries concerning interpretations of technical aspects of this Standard.Periodically certainactionsoftheASMEB16CommitteemaybepublishedasCases.Casesandinterpretationsarepubl
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10、f 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 2022 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights
11、 reservedCONTENTSForeword.vCommittee Roster.viiCorrespondence With the B16 Committee.viiiSummary of Changes.xList of Changes in Record Number Order.xi1Scope.12General.13PressureTemperature Ratings.14Size.25Marking.26Material.37Dimensions and Tolerances.38Threading.39Ribs.410Plugs,Bushings,and Locknu
12、ts.411Face Bevel.412Coatings.4Mandatory AppendixIReferences.22Nonmandatory AppendixAQuality System Program.23Figures4.2-1Identification of Reducing Fittings.28.2-1Gaging of Chamfered Internal Threads.21Tables3-1PressureTemperature Ratings.27.1-1Dimensions of Class 150 90-deg Elbows,Tees,and Crosses,
13、and 45-deg Elbows(Straight Sizes)57.1-2Dimensions of Class 150 45-deg Y-Branches(Straight Sizes).67.1-3Dimensions of Class 150 Street Tees and 90-deg and 45-deg Street Elbows.77.1-4Dimensions of Class 150 Closed-,Medium-,and Open-Pattern Return Bends.87.1-5Dimensions of Class 300 90-deg Elbows,Tees,
14、and Crosses,and 45-deg Elbows(Straight Sizes)97.1-6Dimensions of Class 300 Couplings.107.1-7Dimensions of Class 300 Caps.117.1-8Dimensions of Class 300 90-deg and 45-deg Street Elbows.12iii7.1-9Dimensions of Class 300 Return Bends.137.2.1-1Dimensions of Class 150 90-deg Elbows and Crosses(Reducing S
15、izes).147.2.1-2Dimensions of Class 150 Tees(Reducing Sizes).157.2.1-3Dimensions of Class 150 Couplings(Straight and Reducing Sizes).177.2.1-4Center-to-End Dimensions of Class 300 90-deg Elbows(Reducing Sizes).187.2.1-5Center-to-End Dimensions of Class 300 Tees(Reducing Sizes).187.2.1-6Dimensions of
16、Class 300 Reducing Couplings.197.3-1Inspection Tolerances.198.1-1Dimensions of Class 150 Caps.20ivFOREWORDIn 1921,the American Engineering Standards Committee,later the American Standards Association(ASA)andcurrently the American National Standards Institute(ANSI),authorized the organization of a Sectional Committeeon the Standardization of Pipe Flanges and Flanged Fittings,with the following organizations as joint sponsors:Heating,Piping,and Air Conditioning Contractors National Association lat
