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 appr oves the issuance of a new editio
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12、enue, New York, NY 10016-5990Copyright 2017 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vCommittee Ro
13、ster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viCorrespondence With the B31 Committee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiIntroduction . . . . .
14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Definitions . . . . . . .
15、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Document Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Nonmandatory AppendicesA Stress Intensification Factor (SI
16、F) Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17B Test Method for Determining Branch Connection Flexibility Factors . . . . . . . . . . . . . . . . . . . . . 25C Use of Branch Connection Flexibility Factors in Piping System Analysis . . . . . . . . . . . . . .
17、 . . . . . 34D Sustained Load Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Figures1-1 Orientations for Sketches 2.1 Through 2.6 of Table 1-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131-2 Orientations for Bends .
18、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141-3 Branch Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141-4 Flexibility and Stress Intensification Factors for B
19、ends and Miters . . . . . . . . . . . . . . . . . . . . . . 151-5 Flanged End Corrections for Bends and Miters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151-6 Flexibility Element Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20、 . . . . . . . . 161-7 Fillet Weld Contours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16A-1.1-1 Representative Cantilever Test Arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17A-1.3-1 Displace
21、ment and Force or Moment Recorded During Loading and Unloading of a Test Specimen inBoth Positive and Negative Directions, With Linear Displacement . . . . . . . . . . . . . . . . . . . . . 19B-1-1 Branch Connection Specimen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22、 . . . . . . . . . . . 25B-1-2 Multiple k -Factor Tests on Single Assembled Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26B-2-1 Example Flexibility Factor Branch Load Assembly Orientation . . . . . . . . . . . . . . . . . . . . . . . . . 27B-4.4-1 Detailed Beam Model for T
23、hrough-Branch k -Factor Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29B-4.4-2 Beam Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29B-4.6-1 Load-Displacement Diagram . . . . . . . . . . . . . . . .
24、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31B-6-1 Unreinforced Branch Connection With (Left) and Without Ovalization Restraint Plates in Place . 32C-2-1 Rotational Stiffness Location Between Two Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35C-2
25、-2 Branch Connection In-Plane Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35C-2-3 Branch Connection Flexibilities Used on Branch Side Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36C-2-4 Branch Connection Flexibilities Used on Run S
26、ide Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36C-2-5 Branch and Run Flexibilities Used Together (In Series) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36C-2-6 Rotational Flexibility Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、 . . . . . . . . . . . . . . 37iiiC-2-7 Branch and Run SIF and k -Factor Intersection Orientations . . . . . . . . . . . . . . . . . . . . . . . . . . . 37D-1-1 Standard Sustained Load Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38D-1-2 Bend
28、Sustained Load Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39D-2-1 Load-Displacement Diagram Illustrating Typical Pressure- Sensitive, Not Pressurized, and Not-Pressure- Sensitive Load-Deflection Behavior . . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . . . . . . . . 40D-3-1 Load-Displacement Diagram at ds= 2 deLimit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Tables1-1 Flexibility and Stress Intensification Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
30、1-2 Moment-Rotation Relationships for Sketches 2.1 Through 2.6 of Table 1-1 . . . . . . . . . . . . . . . . 131-3 Flanged End Correction Coefficients for Sketches 2.1 Through 2.6 of Table 1-1 . . . . . . . . . . . . . 13A-2.4-1 Stress Intensification Increase Factor . . . . . . . . . . . . . . . . .
31、 . . . . . . . . . . . . . . . . . . . . . . . . . . 20B-1-1 Load-Deflection Pairs for Single Assembled Orientation Shown in Figure B-1-2 . . . . . . . . . . . . . 26D-8.1-1 Distance and Precaution for Pressurized Twice Elastic Slope Test . . . . . . . . . . . . . . . . . . . . . . . 47D-8.1-2 Inadv
32、ertent Air Volumes in Test Specimens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47ivFOREWORDIn 1990 The American Society of Mechanical Engineers (ASME) B31 Code for Pressure Piping Technical Committee onMechanical Design (MDC) realized that there was a need for a s
33、tandard 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 variousstandard fittings and joints but did not provide guidance on how to conduct further research on existing SIFs or how toestablis
34、h SIFs for nonstandard and other standard fittings or joints.In 2001 the Committee realized that SIFs and k -factors in the various B31 Code books were not consistent or up to date,and so ASME initiated a research project completed by the MDC to incorporate recent research and current manufacturingp
35、ractices 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.This document provides a standard approach for the development of SIFs, k -factors, and sustained stress multipliers forpiping components and joints of
36、 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 or joint. Multipliers of the nominal bending stress due to sus
37、tainedloads currently exist explicitly in some, but not all, B31 books. Where more accurate sustained stresses are needed but anequation for the sustained stress is not given in the B31 Code book, nominal stresses due to sustained moments computedusing the section modulus of the matching pipe should
38、 be multiplied by the appropriate sustained stress multiplier.Where the sustained stress is needed and an equation for the sustained stress is given in the Code book as a function of theSIF and provided in lieu of more applicable data, the sustained stress multipliers developed using the method in t
39、hisStandard 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 availabl
40、e 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 to
41、develop branch connection flexibility factors. Nonmandatory Appendix C demonstrates how the new branch connectionk -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 -f
42、actors for bends, elbows, and straight pipe isavailable in WRC Bulletin 463, “Report 1: Standardized Method for Developing Flexibility Factors for Piping Components, ”E. C. Rodabaugh and E. A. Wais (July 2001).In its development, this Standard has been reviewed by individuals and appropriate subcomm
43、ittees of the Boiler andPressure 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 t
44、he American National Standards 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 ME CHANICAL DESIGN TEC
45、HNICAL COMMITTEE PERSONNELG. A. Antaki , 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
46、 , ConsultantJ. D. Hart , SSD, Inc.B. P. Holbrook , 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, they should not contain proprietary names orinformation.Requ
47、ests that are not in the format described above may be rewritten in the appropriate format by the Committee priorto being answered, which may inadvertently change the intent of the original request.ASME procedures provide for reconsideration of any interpretation when or if additional information th
48、at might affectan interpretation is available. Further, persons aggrieved by an interpretation may appeal to the cognizant ASMECommittee or Subcommittee. ASME does not “approve, ” “certify, ” “rate, ” or “endorse” any item, construction, proprietarydevice, or activity.Attending Committee Meetings. T
49、he B31 Standards Committee regularly holds meetings and/or telephone confer-ences that are open to the public. Persons wishing to attend any meeting and/or telephone conference should contact theSecretary of the B31 Standards Committee.viiINTENTIONALLY LEFT BLANKviiiINTRODUCTIONThe ASME B31 Code for Pressure Piping consists of a number of individually published Sections and Standards, each anAmerican National Standard, under the direction of the ASME B31 Code for Pressure Piping Committee.Rules for each Section reflect the kinds of piping installations considered during its development
