1、ASME B31.1 INTERPRETATIONSASME B31.1INTERPRETATIONS VOLUME 47Replies to Technical InquiriesJanuary 1, 2012 Through December 31, 2013FOREWORDIt has been agreed to publish interpretations issued by the B31 Committee concerning B31.1as part of the update service to the Code. The interpretations have be
2、en assigned numbers inchronological order. Each interpretation applies either to the latest Edition at the time of issuanceof the interpretation or the Edition or Addenda stated in the reply. Subsequent revisions to theCode may have superseded the reply.The replies are taken verbatim from the origin
3、al letters, except for a few typographical andeditorial corrections made for the purpose of improved clarity. In some instances, a review ofthe interpretation revealed a need for corrections of a technical nature. In these cases, a revisedreply bearing the original interpretation number with the suf
4、fix R is presented. In the case whereaninterpretationiscorrectedbyerrata,theoriginalinterpretationnumberwiththesuffixEisused.ASME procedures provide for reconsideration of these interpretations when or if additionalinformation is available which the inquirer believes might affect the interpretation.
5、 Further,persons aggrieved by an interpretation may appeal to the cognizant ASME committee or subcom-mittee. As stated in the Statement of Policy in the Code documents, ASME does not “approve,”“certify,” “rate,” or “endorse” any item, construction, proprietary device, or activity.I-1ASME B31.1 INTER
6、PRETATIONSB31.1Subject Interpretation File No.Figure 127.4.8(D). 47-4 13-849Paragraph 102.3.1(A) (B31.1-2010) 47-1 11-1428Paragraph 127.3(D), Preparation for Welding Spacing (B31.1-2010) 47-5 13-1348Table 132, P-No. 5A (B31.1-2010). 47-2 12-742Table D-1 (B31.1-2010) 47-6 11-1206Welder Requirements (
7、B31.1-2010) . 47-3 11-2032I-2ASME B31.1 INTERPRETATIONSInterpretation: 47-1Subject: Paragraph 102.3.1(A) (B31.1-2010)Date Issued: February 13, 2012File: 11-1428Question: Per ASME B31.1-2010, para. 102.3.1(A), where the weld joint efficiency factor(Ep0.85) is applicable, is the weld joint efficiency
8、factor included in the Appendix A tabulatedvalues of allowable stress?Reply: Yes.Interpretation: 47-2Subject: Table 132, P-No. 5A (B31.1-2010)Date Issued: May 14, 2013File: 12-742Question: For ASME B31.1-2010, may the minimum postweld heat treatment holding tempera-ture range in Table 132 for P-5A b
9、e reduced from 1,300F to 1,250F?Reply: No.Interpretation: 47-3Subject: Welder Requirements (B31.1-2010)Date Issued: May 24, 2013File: 11-2032Question(1): Whenthedesign stipulatesB31.1-2010 forBoilerExternal Piping,cana non-ASMEStamp Holder perform the welding?Reply (1): No.Question (2): When the des
10、ign stipulates B31.1-2010 for Nonboiler External Piping, can anon-ASME Stamp Holder perform the welding?Reply (2): Yes.Question (3): Can a non-ASME Stamp Holder perform repairs to B31.1 piping?Reply (3): This question is outside the scope of ASME B31.1.Interpretation: 47-4Subject: Figure 127.4.8(D)D
11、ate Issued: November 13, 2013File: 13-849Question: May the stress intensification factor for a branch connection listed in Table D-1 beused for the piping connections shown in Fig. 127.4.8(D), Some Acceptable Types of WeldedBranch Attachment Details Showing Minimum Acceptable Welds?Reply: Yes, provi
12、ded the requirements of the Notes of Table D-1 are met.I-3ASME B31.1 INTERPRETATIONSInterpretation: 47-5Subject: Paragraph 127.3(D), Preparation for Welding Spacing (B31.1-2010)Date Issued: November 18, 2013File: 13-1348Question: Per ASME B31.1-2010, Chapter V, para. 127.3(D), Spacing, is the root o
13、pening of aweld joint required to be within the range specified in the WPS?Reply: Yes.Interpretation: 47-6Subject: Table D-1 (B31.1-2010)Date Issued: December 4, 2013File: 11-1206Question: When the geometric or other limitations in ASME B31.1-2010, Table D-1 are not metor for items not listed in Tab
14、le D-1, is the designer responsible for determining the properflexibility and stress intensification factors?Reply: Yes.I-4ASME B31.1 CASESB31.1 Cases No. 37A Case is the official method of handling a reply to an inquiry when study indicates that theCode wording needs clarification, or when the repl
15、y modifies the existing requirements of theCode or grants permission to use new materials or alternative constructions.The text of proposed new and revised B31.1 Cases appear on the ASME Web site athttp:/cstools.asme.org/csconnect/CommitteePages.cfm?CommitteepN10020200 for publicreview. New and revi
16、sed Cases, as well as announcements of annulments, then appear on theWeb site and in the next edition. As of the 1992 and later editions, all Cases currently in effectat the time of publication of an edition are included with it.This update, Cases No. 37, which is included after the last page of the
17、 2014 Edition and theInterpretations Volume 47 that follow, contains the following Cases:175 182 183-1 187 189 190 192The page numbers for the Cases supplements start with C-1 and continue consecutively. TheCases affected by this supplement are as follows:Page Location ChangeC-2 Case 175 AnnulledC-5
18、 Case 183-1 RevisedC-8 Case 189 AddedC-11 Case 190 AddedC-13 Case 192 AddedC-1ASME B31.1 CASESB31 CASE 175ASTM B16 (UNS C36000) and B453 (UNS C35300) in ASME B31.1 ConstructionAnnulment Date: September 28, 2013Reason for Annulment: Requirements incorporated in ASME B31.1 Code.C-2ASME B31.1 CASESB31
19、CASE 182Use of 1.15Ni0.65CuMoCb in ASME B31.1 ConstructionApproval Date: November 10, 2006Inquiry: May A335-05a P36 Class 1 and Class 2, andA182-05a F36 Class 1 and Class 2, be used for B31.1construction?Reply: It is the opinion of the Committee thatA335-05a P36 Class 1 and Class 2, and A182-05a F36
20、Class 1 and Class 2, may be used for B31.1 constructionprovided that all of the following requirements are met:(a) All applicable requirements of ASME B31.1 shallbe met.(b) The maximum allowable stress values and otherdata shown in Table 1 or 1M apply.(c) Separate weld procedure and performance qual
21、ifi-cations shall apply for both classes of this material. Thepostweld heat treatment of the Class 1 and Class 2 mate-rial shall be in accordance with the rules specified inTable 2 or 2M.(d) After either cold bending to strains in excess of5% or any hot bending of this material, the full lengthof th
22、e component shall be heat treated in accordancewith the requirements specified in the material specifica-tion. (See PG-19 of Section I for method for calculatingstrain.)(e) Postweld heat treatment is mandatory under allconditions.C-3(f) This Case number shall be referenced in the docu-mentation and
23、marking of the material, and recordedon the Manufacturers Data Report (if applicable).CAUTIONARY NOTE: Corrosion fatigue occurs by the com-bined actions of cyclic loading and a corrosive environment.In piping systems, corrosion fatigue is more likely to occur inportions of water systems with low str
24、ain rates (0.04 ppm), with a preference toward regions withincreasedlocalstresses.Whilethemechanismsofcrackinitiationand growth are complex and not fully understood, there is con-sensus that the two major factors are strain and waterside envi-ronment. Strain excursions of sufficient magnitude to fra
25、cturethe protective oxide layer play a major role. In terms of thewaterside environment, high levels of dissolved oxygen and pHexcursions are known to be detrimental. Historically, the steelsapplied in these water-touched components have had the mini-mum specified yield strengths in the range of 27
26、ksi to 45 ksi(185 MPa to 310 MPa) and minimum specified tensile strengthsin the range of 47 ksi to 80 ksi (325 MPa to 550 MPa). As thesematerials are supplanted by higher strength steels, some haveconcern that the higher design stresses and thinner wall thick-nesses will render components more vulne
27、rable to failures bycorrosion fatigue. Thus, when employing such higher strengthsteels for water systems, it is desirable to use “best practices”in design by minimizing localized strain concentrations, in con-trol of water chemistry and during lay-up by limiting dissolvedoxygen and pH excursions, an
28、d in operation by conservativestartup, shutdown, and turndown practices.ASME B31.1 CASESTable 1 Maximum Allowable Stress ValuesMaximum AllowableStress Values, ksiFor Metal TemperatureNot Exceeding, F Class 1 Class 220 to 100 25.7 27.3200 25.7 27.3300 25.1 26.6400 25.1 26.6500 25.1 26.6600 25.1 26.67
29、00 25.1 26.6Table 1M Maximum Allowable Stress ValuesMaximum AllowableStress Values, MPaFor Metal TemperatureNot Exceeding, C Class 1 Class 230 to 40 177 188100 177 188150 173 183200 173 183250 173 183300 173 183350 173 183371 173 183C-4Table 2 Requirements for Postweld HeatTreatment (PWHT)PWHTTemper
30、ature,Class F Holding Time1 1,1001,200 2 in. and less thickness: 1 hr/in., 15 minminimumOver 2 in.: add 15 min for each additionalinch of thickness2 1,0001,150 1 hr/in.,12hr min.Table 2M Requirements for Postweld HeatTreatment (PWHT)PWHTTemperature,Class C Holding Time1 595650 50 mm and less thickne
31、ss: 1 hr/25 mm,15 min minimumOver 50 mm: add 15 min for eachadditional 25 mm of thickness2 540620 1 hr/25 mm,12hr min.ASME B31.1 CASESB31 CASE 183-1Use of 9Cr2W, UNS No. K92460, in ASME B31.1 ConstructionApproval Date: September 25, 2013Inquiry: May 9Cr2W, UNS No. K92460, material con-forming to one
32、 of the specifications listed in Table 1 beused for ASME B31.1 construction?Reply: It is the opinion of the Committee that 9Cr2W,UNS No. K92460, material conforming to one of thespecifications listed in Table 1 may be used forASME B31.1 construction provided the following addi-tional requirements ar
33、e met:(a) ASTM A369 Grade FP92 material shall not exceeda hardness of 250 HBW/265 HV (25 HRC).(b) The maximum allowable stress values for thematerial shall be those given in Table 2. The maximumuse temperature for the material shall be 1,200F (649C).(c) For the purpose of procedure and performancequ
34、alifications, the material shall be consideredP-No. 15E, Group 1. The procedure and performancequalifications shall be conducted in accordance withSection IX. Postweld heat treatment for this material ismandatory, and the following rule shall apply: ThePWHT requirements shall be those given for P-No
35、. 15E,Group 1 materials in Table 132.(d) Repair welding of base material shall be permittedas prescribed by the applicable material product specifi-cation or its general requirements specification. Allrepair welds shall be in accordance with Section IX usingone of the following processes: SMAW, SAW,
36、 GTAW, orFCAW. The composition of the welding consumablesshall be such that the lower critical transformation tem-perature of the consumables shall exceed the maximumpostweld heat treatment temperature in (c) above. If thelower critical transformation temperature is calculatedrather than measured, t
37、he formula used shall bereported. If requested, data supporting the validity ofthe formula shall be provided by the material manufac-turer. All repair welds to base material shall be normal-ized and tempered according to the requirements of theapplicable material specification. The material manufac-
38、turer shall provide a complete report of all repair welds.(e) If, during the manufacturing, any portion of thecomponent is heated to a temperature greater than1,470F (800C), then the component must be reaustenit-ized and retempered in its entirety in accordance withthe applicable material specificat
39、ion, or that portion ofthe component heated above 1,470F (800C), includingthe heat-affected zone created by the local heating, mustC-5be replaced, or must be removed, reaustenitized, andretempered, and then replaced in the component.(f) 9Cr2W materials subject to forming or bendingshall be heat trea
40、ted in accordance with the followingrules:(1) When the material is cold formed or cold bent,cold-forming strains shall be calculated in accordancewith para. 129.3.4.1 or 129.3.4.2.(2) If normalizing and tempering is performed, itshall not be performed locally. The pipe, tube, or compo-nent to be nor
41、malized and tempered shall either be heattreated in its entirety, or the area (including the transitionto the unstrained portion) shall be cut away from thebalance of the pipe, tube, or component and heat treatedseparately or replaced.(3) If hot bending or hot forming is performed, andfor all cold s
42、wages, flares, or upsets, normalizing andtempering of the material is required in accordance withthe requirements in the base material specification.(4) If cold bending or cold forming is performed,the material shall be heat treated as follows:(-a) For materials with 20% strain with designtemperatur
43、es exceeding 1,115F (600C), or for materialswith 25% strain with design temperatures between1,000F (540C) and 1,115F (600C), inclusive, the cold-strained area of the component shall be normalized andtempered in accordance with the requirements of thebase material specification.(-b) For materials wit
44、h 5% strain but 20%strain with design temperatures exceeding 1,115F(600C), or with 5% strain but 25% strain with designtemperatures between 1,000F (540C) and 1,115F(600C), inclusive, the cold-strained areas shall be heattreated at 1,350F to 1,425F (730C to 775C) for 1 hr/in.(1 h/25 mm) or 30 min min
45、imum. As an alternative,normalization and temper in accordance with therequirements of the base material specification may besubstituted for the heat treatment required in thisparagraph.(-c) If only a portion of a cold-bent or cold-formed piping component is heated above the heat treat-ment temperat
46、ure allowed above, and the material wassubjected to strains 5% but 25% for design tempera-tures 1,115F (600C), one of the following actions shallbe performed:(-1) The component in its entirety shall berenormalized and tempered in accordance with therequirements of the base metal specification.ASME B
47、31.1 CASES(-2) The allowable stress shall be that for Gr. 9material (i.e., A335 P9 or equivalent product specifica-tion) at the design temperature, provided that the por-tion of the component that was heat treated to atemperature exceeding the maximum holding tempera-ture is subjected to a final hea
48、t treatment within thetemperature range and for the time required inpara. (4)(-b) above. For Boiler External Piping, the useof this provision shall be noted on the ManufacturersData Report.Table 1 Material Specifications and GradesProduct Form ASTM Specification No.Flanges, forged fittings, valves,
49、and parts A182/A182M-11a, Grade F92Seamless tubes A213/A213M-08, Grade T92Seamless pipe A335/A335M-06, Grade P92Forgings A336/A336M-10a, Grade F92Forged and bored pipe A369/A369M-06, Grade FP92Plate A1017/A1017M-11, Grade 92Table 2 Maximum Allowable Stress ValuesFor Metal Temperature For Metal TemperatureNot Exceeding, F Stress, ksi Not Exceeding, C Stress, MPa20 to 100 25.7 30 to 40 177200 25.7 85 177300 25.3 100 177400 24.5 125 177500 23.8 150 174600 23.2 200 169650 22.8 250 165700 22.4 300 161750 21.9 325 159800 21.4 350 156850 2
