1、Stress Intensification Factors (i-Factors), Flexibility Factors (k-Factors), and Their Determination for Metallic Piping ComponentsASME Code for Pressure Piping, B31AN AMERICAN NATIONAL STANDARDASME B31J-2017Revision of ASME B31J-2008 (R2013)ASME B31J-2017Revision of ASME B31J-2008 (R2013)Stress Int
2、ensification Factors (i-Factors), Flexibility Factors(k-Factors), and Their Determination for Metallic Piping ComponentsASME Code for Pressure Piping, B31AN AMERICAN NATIONAL STANDARDxDate of Issuance: June 16, 2017This Standard will be revised when the Society approves the issuance of a new edition
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10、 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 elect
11、ronicretrieval system or otherwise, without the prior written permission of thepublisher.The American Society of Mechanical EngineersTwo Park Avenue, New York, NY 10016-5990Copyright 2017 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword . . . . . . .
12、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vCommittee Roster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viCorrespondence Wi
13、th the B31 Committee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix1 General . . . . . . .
14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Document Contents . . . . . . . . . . . . .
15、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Nonmandatory AppendicesA Stress Intensification Factor (SIF) Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17B Test Method for Determining Branch Connection Flexibility Factors
16、. . . . . . . . . . . . . . . . . . . . . 25C Use of Branch Connection Flexibility Factors in Piping System Analysis . . . . . . . . . . . . . . . . . . . 34D Sustained Load Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Figures1-1 Or
17、ientations for Sketches 2.1 Through 2.6 of Table 1-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131-2 Orientations for Bends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141-3 Branch Dimensions . . . . . . . . . . . . .
18、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141-4 Flexibility and Stress Intensification Factors for Bends and Miters . . . . . . . . . . . . . . . . . . . . . . 151-5 Flanged End Corrections for Bends and Miters . . . . . . . . . . . . . . . . . . . . . . .
19、 . . . . . . . . . . . . . 151-6 Flexibility Element Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161-7 Fillet Weld Contours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
20、A-1.1-1 Representative Cantilever Test Arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17A-1.3-1 Displacement and Force or Moment Recorded During Loading and Unloading of a Test Specimen inBoth Positive and Negative Directions, With Linear Displacement . . . .
21、. . . . . . . . . . . . . . . . . 19B-1-1 Branch Connection Specimen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25B-1-2 Multiple k-Factor Tests on Single Assembled Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26B-2-1 Ex
22、ample Flexibility Factor Branch Load Assembly Orientation . . . . . . . . . . . . . . . . . . . . . . . . . 27B-4.4-1 Detailed Beam Model for Through-Branch k-Factor Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29B-4.4-2 Beam Model . . . . . . . . . . . . . . . . . . . . . . . .
23、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29B-4.6-1 Load-Displacement Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31B-6-1 Unreinforced Branch Connection With (Left) and Without Ovalization Restraint Plate
24、s in Place . 32C-2-1 Rotational Stiffness Location Between Two Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35C-2-2 Branch Connection In-Plane Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35C-2-3 Branch Connection Flexib
25、ilities Used on Branch Side Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36C-2-4 Branch Connection Flexibilities Used on Run Side Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36C-2-5 Branch and Run Flexibilities Used Together (In Series) . . . . . . . . . . . . .
26、. . . . . . . . . . . . . . . . . 36C-2-6 Rotational Flexibility Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37iiiC-2-7 Branch and Run SIF and k-Factor Intersection Orientations . . . . . . . . . . . . . . . . . . . . . . . . . . . 37D-1-
27、1 Standard Sustained Load Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38D-1-2 Bend Sustained Load Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39D-2-1 Load-Displacement Diagram Illu
28、strating Typical Pressure-Sensitive, Not Pressurized, and Not-Pressure-Sensitive Load-Deflection Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40D-3-1 Load-Displacement Diagram at ds= 2deLimit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29、. 42Tables1-1 Flexibility and Stress Intensification Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-2 Moment-Rotation Relationships for Sketches 2.1 Through 2.6 of Table 1-1 . . . . . . . . . . . . . . . . 131-3 Flanged End Correction Coefficients for Sketches
30、 2.1 Through 2.6 of Table 1-1 . . . . . . . . . . . . . 13A-2.4-1 Stress Intensification Increase Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20B-1-1 Load-Deflection Pairs for Single Assembled Orientation Shown in Figure B-1-2 . . . . . . . . . . . .
31、. 26D-8.1-1 Distance and Precaution for Pressurized Twice Elastic Slope Test . . . . . . . . . . . . . . . . . . . . . . . 47D-8.1-2 Inadvertent Air Volumes in Test Specimens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47ivFOREWORDIn1990TheAmericanSocietyofMechanica
32、lEngineers(ASME)B31CodeforPressurePipingTechnicalCommitteeonMechanical Design (MDC) realized that there was a need for a standard method to develop stress intensification factors(SIFs or i-factors) for ASME piping components and joints. At the time, the B31 Code books provided SIFs for variousstanda
33、rd fittings and joints but did not provide guidance on how to conduct further research on existing SIFs or how toestablish SIFs for nonstandard and other standard fittings or joints.In2001theCommitteerealizedthatSIFsandk-factorsinthevariousB31Codebookswerenotconsistentoruptodate,andsoASMEinitiatedar
34、esearchprojectcompletedbytheMDCtoincorporaterecentresearchandcurrentmanufacturingpractices in the SIF and k-factor test procedures, to provide a consistent and up-to-date table of SIFs and k-factors formetallic piping components.ThisdocumentprovidesastandardapproachforthedevelopmentofSIFs,k-factors,
35、andsustainedstressmultipliersforpiping components and joints of all types, including standard, nonstandard, and proprietary fittings.Sustained stress multipliers are used to multiply the nominal bending stress due to sustained loading and reflect thecollapse capacity of the metallic piping component
36、 or joint. Multipliers of the nominal bending stress due to sustainedloadscurrentlyexistexplicitlyinsome,butnotall,B31books.WheremoreaccuratesustainedstressesareneededbutanequationforthesustainedstressisnotgivenintheB31Codebook,nominalstressesduetosustainedmomentscomputedusing the section modulus of
37、 the matching pipe should be multiplied by the appropriate sustained stress multiplier.WherethesustainedstressisneededandanequationforthesustainedstressisgivenintheCodebookasafunctionoftheSIF and provided in lieu of more applicable data, the sustained stress multipliers developed using the method in
38、 thisStandard may be substituted as more applicable data and used with the nominal stress computed using the sectionmodulus of the matching pipe.The most applicable currently available stress intensification and flexibility factors compiled from test and analysisdata for standard commercially availa
39、ble metallic components are included in Table 1-1 and should be used with thesection modulus of the matching pipe (not an “effective” section modulus). Nonmandatory Appendix A provides thestandard method to develop stress intensification factors. Nonmandatory Appendix B provides the standard method
40、todevelopbranchconnectionflexibilityfactors.NonmandatoryAppendixCdemonstrateshowthenewbranchconnectionk-factors should be used in the elastic analysis of piping systems, and Nonmandatory Appendix D provides a standardmethod to develop sustained stress factors. A procedure to develop k-factors for be
41、nds, elbows, and straight pipe isavailableinWRCBulletin463,“Report1:StandardizedMethodforDevelopingFlexibilityFactorsforPipingComponents,”E. C. Rodabaugh and E. A. Wais (July 2001).In its development, this Standard has been reviewed by individuals and appropriate subcommittees of the Boiler andPress
42、ure Vessel Code, B31, and B16 Committees. Comments resulting from the review have been considered andresponded to, with revisions made to the Standard, as appropriate. The 2017 edition has been revised in its entirety.It was approved as an American National Standard by the American National Standard
43、s Institute on January 11, 2017.vASME B31 COMMITTEECode for Pressure Piping(The following is the roster of the Committee at the time of approval of this Standard.)COMMITTEE OFFICERSG. A. Antaki, ChairJ. E. Meyer, Vice ChairR. Lucas, SecretaryB31 MECHANICAL DESIGN TECHNICAL COMMITTEE PERSONNELG. A. A
44、ntaki, Becht Engineering Co., Inc.C. Becht IV, Becht Engineering Co., Inc.N. Consumo, Sr., ConsultantJ. P. Ellenberger, RetiredM. Engelkemier, Stanley Consultants, Inc.D. J. Fetzner, BP Exploration Alaska, Inc.D. Fraser, NASA Ames Research CenterJ. A. Graziano, ConsultantJ. D. Hart, SSD, Inc.B. P. H
45、olbrook, ConsultantW. J. Koves, Pi Engineering Software, Inc.R. A. Leishear, Leishear Engineering, LLCR. Lucas, The American Society of Mechanical EngineersG. D. Mayers, Alion Science however,theyshouldnotcontainproprietarynamesorinformation.Requeststhatarenotintheformatdescribedabovemayberewritteni
46、ntheappropriateformatbytheCommitteepriorto being answered, which may inadvertently change the intent of the original request.ASMEproceduresprovideforreconsiderationofanyinterpretationwhenorifadditionalinformationthatmightaffectan interpretation is available. Further, persons aggrieved by an interpre
47、tation may appeal to the cognizant ASMECommitteeorSubcommittee.ASMEdoesnot“approve,”“certify,”“rate,”or“endorse”anyitem,construction,proprietarydevice, or activity.Attending Committee Meetings. The B31 Standards Committee regularly holds meetings and/or telephone confer-encesthatareopentothepublic.P
48、ersonswishingtoattendanymeetingand/ortelephoneconferenceshouldcontacttheSecretary of the B31 Standards Committee.viiINTENTIONALLY LEFT BLANKviiiINTRODUCTIONTheASMEB31CodeforPressurePipingconsistsofanumberofindividuallypublishedSectionsandStandards,eachanAmerican National Standard, under the directio
49、n of the ASME B31 Code for Pressure Piping Committee.Rules for each Section reflect the kinds of piping installations considered during its development, as follows:(a) B31.1,PowerPiping:pipingtypicallyfoundinelectricgeneratingstations,inindustrialandinstitutionalplants,ingeothermal and solar power applications, and in central and district heating and cooling systems(b) B31.3, Process Piping: piping typically found in petroleum refineries and in chemical, pharmaceutical, textile,paper, semiconductor, cryogenic, and related processing plants and terminals(c) B31.4, Pipeline Transportatio
