1、Gas Transmission and Distribution Piping SystemsASME Code for Pressure Piping, B31AN AMERICAN NATIONAL STANDARDASME B31.8-2007(Revision of ASME B31.8-2003)Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from I
2、HS-,-,-ASME B31.8-2007(Revision of ASME B31.8-2003)Gas Transmission andDistribution PipingSystemsASME Code for Pressure Piping, B31AN AMERICAN NATIONAL STANDARDThree Park Avenue New York, NY 10016Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or ne
3、tworking permitted without license from IHS-,-,-Date of Issuance: November 30, 2007The next edition of this Code is scheduled for publication in 2009. There will be no addenda issuedto this edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of this Code.
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10、onic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2007 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.Copyright ASME International
11、 Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-CONTENTSForeword viiCommittee Roster . ixIntroduction . xiiSummary of Changes xivGeneral Provisions and Definitions801 General 1802 Scope and Intent . 1803 Piping Systems Defin
12、itions . 2804 Piping Systems Component Definitions . 4805 Design, Fabrication, Operation, and Testing Terms 6807 Quality Assurance . 7Chapter I Materials and Equipment810 Materials and Equipment 8811 Qualification of Materials and Equipment 8812 Materials for Use in Cold Climates . 9813 Marking . 98
13、14 Material Specifications . 9815 Equipment Specifications . 9816 Transportation of Line Pipe 9817 Conditions for the Reuse of Pipe . 10Chapter II Welding820 Welding . 12821 General 12822 Preparation for Welding 12823 Qualification of Procedures and Welders 12824 Preheating . 13825 Stress Relieving
14、13826 Inspection of Welds 14827 Repair or Removal of Defective Welds in Piping Intended to Operate atHoop Stress Levels of 20% or More of the Specified Minimum YieldStrength . 15Chapter III Piping System Components and Fabrication Details830 Piping System Components and Fabrication Details . 16831 P
15、iping System Components 16832 Expansion and Flexibility 22833 Design for Longitudinal Stress . 23834 Supports and Anchorage for Exposed Piping . 26835 Anchorage for Buried Piping . 26Tables831.42 Reinforcement of Welded Branch Connections, Special Requirements 21832.2 Thermal Expansion of Carbon and
16、 Low Alloy Steel . 23832.5 Modulus of Elasticity for Carbon and Low Alloy Steel 23Chapter IV Design, Installation, and Testing840 Design, Installation, and Testing 28841 Steel Pipe 30842 Other Materials 41843 Compressor Stations . 48iiiCopyright ASME International Provided by IHS under license with
17、ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-844 Pipe-Type and Bottle-Type Holders . 51845 Control and Limiting of Gas Pressure 52846 Valves . 59847 Vaults . 60848 Customers Meters and Regulators . 61849 Gas Service Lines 62Tables841.114A Basic Design Facto
18、r, F 32841.114B Design Factors for Steel Pipe Construction 32841.115A Longitudinal Joint Factor, E 33841.116A Temperature Derating Factor, T, for Steel Pipe 33841.322(f) Test Requirements for Pipelines and Mains to Operate at HoopStresses of 30% or More of the Specified Minimum Yield Strength ofthe
19、Pipe . 40841.33 Maximum Hoop Stress Permissible During Test . 41842.214 Standard Thickness Selection Table for Ductile Iron Pipe 43842.32(c) Wall Thickness and Standard Dimension Ratio for Thermoplastic Pipe 44842.33(c) Diameter and Wall Thickness for Reinforced ThermosettingPlastic Pipe 44842.396(c
20、) Nominal Values for Coefficients of Thermal Expansion of ThermoplasticPipe Materials . 46Chapter V Operating and Maintenance Procedures850 Operating and Maintenance Procedures Affecting the Safety of GasTransmission and Distribution Facilities 66851 Pipeline Maintenance 68852 Distribution Piping Ma
21、intenance . 73853 Miscellaneous Facilities Maintenance . 76854 Location Class and Changes in Number of Buildings Intended forHuman Occupancy 78855 Concentrations of People in Location Classes 1 and 2 . 80856 Pipeline Service Conversions . 80Table854.1(c) Location Class . 79Chapter VI Corrosion Contr
22、ol860 Corrosion Control 82861 Scope 82862 External Corrosion Control . 82863 Internal Corrosion Control . 85864 Pipelines in Arctic Environments . 87865 Pipelines in High-Temperature Service 88866 Stress Corrosion and Other Phenomena 88867 Records . 89Chapter VII Miscellaneous870 Miscellaneous . 908
23、71 Odorization . 90872 Liquefied Petroleum Gas (LPG) Systems 90873 Pipelines on Private Rights-of-Way of Electric Transmission Lines . 91Chapter VIII Offshore Gas TransmissionA800 Offshore Gas Transmission . 92A801 General 92A802 Scope and Intent . 92A803 Offshore Gas Transmission Definitions 92A811
24、 Qualification of Materials and Equipment 93A814 Material Specifications . 93ivCopyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-A817 Conditions for the Reuse and Requalification of Pipe . 93A820 We
25、lding Offshore Pipelines . 94A821 General 94A823 Qualification of Procedures and Welders 94A825 Stress Relieving 94A826 Welding and Inspection Tests 94A830 Piping System Components and Fabrication Details . 95A831 Piping System Components 95A832 Expansion and Flexibility 95A834 Supports and Anchorag
26、e for Exposed Piping . 95A835 Anchorage for Buried Piping . 95A840 Design, Installation, and Testing 95A841 Design Considerations . 95A842 Strength Considerations 97A843 Compressor Stations . 99A844 On-Bottom Stability 100A846 Valves . 101A847 Testing 101A850 Operating and Maintenance Procedures Aff
27、ecting the Safety of GasTransmission Facilities . 102A851 Pipeline Maintenance 103A854 Location Class . 103A860 Corrosion Control of Offshore Pipelines 103A861 Scope 103A862 External Corrosion Control . 103A863 Internal Corrosion Control . 105TableA842.22 Design Factors for Offshore Pipelines, Platf
28、orm Piping, and PipelineRisers . 98Chapter IX Sour Gas ServiceB800 Sour Gas Service . 106B801 General 106B802 Scope and Intent . 106B803 Sour Gas Terms and Definitions 106B813 Marking . 107B814 Material Specifications . 107B820 Welding Sour Gas Pipelines 107B821 General 107B822 Preparation for Weldi
29、ng 107B823 Qualifications of Procedures and Welders . 107B824 Preheating . 107B825 Stress Relieving 107B826 Welding and Inspection Tests 108B830 Piping System Components and Fabrication Details . 108B831 Piping System Components 108B840 Design, Installation, and Testing 108B841 Steel Pipe 108B842 Ot
30、her Materials 109B843 Compressor Stations . 109B844 Pipe-Type and Bottle-Type Holders . 109B850 Additional Operating and Maintenance Considerations Affecting theSafety of Sour Gas Pipelines . 109B851 Pipeline Maintenance 110B855 Concentrations of People in Location Classes 1 and 2 . 110B860 Corrosio
31、n Control of Sour Gas Pipelines 110B861 General 110vCopyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-B862 External Corrosion Control . 110B863 Internal Corrosion Control . 111B866 Stress Corrosion
32、and Other Phenomena 111AppendicesA References . 113B Numbers and Subjects of Standards and Specifications That Appear inAppendix A . 116C Publications That Do Not Appear in the Code or Appendix A 117D Specified Minimum Yield Strength for Steel Pipe Commonly Used inPiping Systems 119E Flexibility and
33、 Stress Intensification Factors . 121F Extruded Headers and Welded Branch Connections . 127G Testing of Welders Limited to Work on Lines Operating at HoopStresses of Less Than 20% of the Specified Minimum Yield Strength 133H Flattening Test for Pipe 134I End Preparations for Buttwelding 135J Commonl
34、y Used Conversion Factors . 143K Criteria for Cathodic Protection 147L Determination of Remaining Strength of Corroded Pipe . 149M Gas Leakage Control Criteria . 150N Recommended Practice for Hydrostatic Testing of Pipelines in Place 156O Preparation of Technical Inquiries 158P Nomenclature for Figu
35、res 159Q Scope Diagrams . 160R Estimating Strain in Dents . 163Index 165viCopyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-FOREWORDThe need for a national code for pressure piping became increasing
36、ly evident from 1915 to1925. To meet this need, the American Engineering Standards Committee (later changed to theAmerican Standards Association, now the American National Standards Institute) initiated ProjectB31 in March 1926 at the request of the American Society of Mechanical Engineers and witht
37、hat Society as sole sponsor. After several years of work by Sectional Committee B31 and itssubcommittees, a first Edition was published in 1935 as an American Tentative Standard Codefor Pressure Piping.A revision of the original tentative standard began in 1937. Several more years of effort weregive
38、n to securing uniformity among sections, eliminating divergent requirements and discrepan-cies, keeping the Code abreast of current developments in welding technique, calculating stresscomputations, and including reference to new dimensional and material standards. During thisperiod, a new section a
39、dded on refrigeration piping was prepared in cooperation with theAmerican Society of Refrigeration Engineers and complemented the American Standard Codefor Mechanical Refrigeration. This work culminated in the 1942 American Standard Code forPressure Piping.Supplements 1 and 2 of the 1942 Code, which
40、 appeared in 1944 and 1947, respectively, introducednew dimensional and material standards, a new formula for pipe wall thickness, and morecomprehensive requirements for instrument and control piping. Shortly after the 1942 Code wasissued, procedures were established for handling inquires requiring
41、explanation or interpretationof Code requirements and for publishing such inquiries and answers in Mechanical Engineeringfor the information of all concerned.By 1948, continuing increases in the severity of service conditions combined with the develop-ment of new materials and designs to meet these
42、higher requirements warranted more extensivechanges in the Code than could be provided from supplements alone. The decision was reachedby the American Standards Association and the sponsor to reorganize the sectional committeeand its several subcommittees and to invite the various interested bodies
43、to reaffirm their represen-tatives or to designate new ones.Because of the wide field involved, between 30 and 40 different engineering societies, govern-ment bureaus, trade associations, institutes, and similar organizations have had one or morerepresentatives on the sectional committee, plus a few
44、 “members at large” to represent generalinterests. Code activities have been subdivided according to the scope of the several sections.General direction of Code activities rested with the Standards Committee officers and an executivecommittee, membership of which consisted principally of Standards C
45、ommittee officers andsection chairmen.Following its reorganization in 1948, Standards Committee B31 made an intensive review ofthe 1942 Code that resulted in(a) a general revision and extension of requirements to agree with present day practice(b) the revision of references to existing dimensional s
46、tandards and material specifications andthe addition of references to the new ones(c) the clarification of ambiguous or conflicting requirementsA revision was presented for letter ballot vote of Standards Committee B31. Following approvalby this body, the project was approved by the sponsor organiza
47、tion and by the American StandardsAssociation. It was finally designated as an American Standard in February 1951, with thedesignation B31.1-1951.Standards Committee B31 at its annual meeting of November 29, 1951, authorized the separatepublication of a section of the Code for Pressure Piping addres
48、sing gas transmission and distribu-tion piping systems, to be complete with the applicable parts of Section 2, Gas and Air PipingSystems, Section 6, Fabrication Details, and Section 7, Materials Their Specifications andIdentification. The purpose was to provide an integrated document for gas transmi
49、ssion anddistribution piping that would not require cross-referencing to other sections of the Code.viiCopyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-The first Edition of this integrated document, known as American Standard Code for PressurePiping, Sectio
