1、ASME B31.3 CASESB31.3 Code CasesASMEissuesrepliestoinquiriesthatareapplicabletoASMEB31.3.Whenareplymodifiestheexistingrequirementsof the Code, the inquiry and reply are issued as a Code Case.Code Cases remain available for use until annulled by the ASME B31 Code for Pressure Piping StandardsCommitte
2、e.B31.3 Code Cases that are approved after this edition will be published on the following ASME web page:http:/cstools.asme.org/csconnect/CommitteePages.cfm?CommitteepN10020400.As of the date of issuance of this edition of B31.3, the following Code Cases are in effect:Case 180 Leak testing of subass
3、emblies of jacketed pipingCase 181 Use of alternative ultrasonic examination acceptance criteriaCase 185 Use of standard helium leak test for a vacuum-only piping system(para. 345)Case 191 Cu13Zn1.1NiSiAl alloy seamless pipe and tubeCase 193 Cu5.5Zn4Si casting alloy UNS No. C87600SUMMARY OF CHANGEST
4、he Code Cases affected by this edition are as follows:Page Code Case ChangeC-8 188 Annulled with the approval of TechnicalRevision 12-849C-9 191 AddedC-10 193 AddedC-1ASME B31.3 CASESB31 CASE 180Leak Testing of Subassemblies of Jacketed Piping for Use in ASME B31.3 Piping SystemsApproval Date: Janua
5、ry 5, 2007Inquiry: Does ASME B31.3 permit an alternate leaktest for jacketed piping in which it is impracticable tovisually examine the welded joints and connections forleaks in accordance with para. 345.2.2(a)?Reply: Visually observing the joints and connectionsduring the leak test in accordance wi
6、th paras. 345.2.2(a)and 345.3.1 is not required, provided all of the followingconditions are satisfied:(a) Theweldedjointsandconnectionsareontheinnerpipe of jacketed piping.C-2(b) A leak test is performed that otherwise meets therequirements of para. 345.1, except visual examinationof joints and con
7、nection in accordance withparas. 345.2.2(a) and 345.3.1 is not required.(c) A sensitive leak test is performed in accordancewithpara.345.8todemonstrateleaktightnessofweldedjoints and connections that are not visually examinedduring the leak testing required in (b) above.ASME B31.3 CASESB31 CASE 181U
8、se of Alternative Ultrasonic Examination Acceptance Criteria in ASME B31.3Approval Date: January 4, 2012Inquiry: Under what conditions and limitations mayalternative UT acceptance criteria apply in lieu of thosedescribed in para. 344.6.2 of ASME B31.3?Reply: When specified by the owner, the ultrason
9、icexamination acceptance criteria included below may beapplied for welds in material greater than or equal to25 mm (1.0 in.) in thickness1in accordance withASME B31.3, provided the following requirements aremet:(a) General/Scope(1) Theexaminationshallbeconductedusingauto-matedorsemiautomatedtechniqu
10、esutilizingcomputer-based data acquisition.(2) The examination shall be performed in accor-dance with a written procedure approved by Level IIIpersonnel and conforming to the requirements ofASME BPV Code Section V, Article 4, MandatoryAppendix VIII and(a) forphasedarrayASMESectionV,Article4,Mandator
11、y Appendix V(b) for time of flight diffraction (TOFD) ASME Section V, Article 4, Mandatory Appendix III(3) Procedure qualification shall meet the require-ments of ASME Section V, Article 4, MandatoryAppendix IX.(b) Equipment. A mechanical guided scanner capableof maintaining a fixed and consistent s
12、earch unit posi-tion relative to the weld centerline shall be used.(c) Personnel(1) Setupandscanningofweldsshallbeperformedby personnel certified as Level II or III (or by Level Ipersonnel under the direct supervision of Level IIpersonnel).(2) Interpretation and evaluation of data shall beperformed
13、by Level II or III personnel.(3) Examination personnel shall be qualified andcertified following a procedure or program as describedin ASME Section V, Article 1, T-120(e), (f), (h), and (i).(4) Personnel demonstration requirements shall beas stated in ASME Section V, Article 4, MandatoryAppendix VII
14、.1For wall thicknesses less than 25 mm (1.0 in.), the acceptancecriteria stated in para. 344.6.2 of B31.3 shall be used.C-3(d) Examination(1) The initial straight beam scan for reflectors thatcould interfere with the angle beam examination shallbe performed(a) manually(b) as part of a previous manuf
15、acturing processor(c) duringtheweldexamination,provideddetec-tion of these reflectors is included in the demonstrationas required in (a)(3) above(2) The examination area shall include the volumeof the weld, plus the lesser of 25 mm (1.0 in.) or t ofadjacent base metal. Alternatively, the examination
16、 vol-ume may be reduced to include the actual heat affectedzone(HAZ)plus6mm(0.25in.)ofbasematerialbeyondtheheataffectedzoneoneachsideoftheweld,providedthe extent of the weld HAZ is measured anddocumented.(3) Scanning may be performed at reference level,provided the procedure qualification was perfor
17、med atreference level.(e) Data Recording. Data shall be recorded in theunprocessedformwithnothresholding.Thedatarecordshall include the complete examination area as specifiedin (d)(2) above.(f) Data Analysis(1) Reflectors exceeding the limits below shall beinvestigated to determine whether the indic
18、ation origi-nates from a flaw or is a geometric indication, in accor-dance with (2) below.(a) Foramplitude-basedtechniques,thelocation,amplitude, and extent of all reflectors that produce aresponse greater than 20% of the reference level shallbe investigated.(b) For non-amplitude-based techniques, t
19、helocation and extent of all images that have an indicatedlength greater than 4.0 mm (0.16 in.) shall beinvestigated.(2) Ultrasonicindicationsofgeometricand/ormet-allurgical origin shall be classified as specified inASME Section V, Article 4, T-481.(3) Alternatively, other techniques or NDE meth-ods
20、 may be used to classify an indication as geometric(e.g.,alternativebeamangles,radiography).Themethodemployed is for information only to classify the indica-tion as geometric, and ASME B31.3 requirements forASME B31.3 CASESexamination techniques are only required to the extentthat they are applicabl
21、e.(g) Flaw Evaluation(1) Dimensions. The dimensions of the flaw(s) shallbe determined by the rectangle that fully contains thearea of the flaw(s). (Refer to Fig. 1.)(a) Thelength,H5129,oftheflawshallbedrawnparal-lel to the inside pressure-retaining surface of thecomponent.(b) The height, h, of the f
22、law shall be drawn nor-mal to the inside pressure-retaining surface of thecomponent.(c) The flaw shall be characterized as a surfaceor subsurface flaw, as shown in Fig. 1.(d) A subsurface indication shall be consideredas a surface flaw if the separation (S in Fig. 1) of theindication from the neares
23、t surface of the component isequal to or less than half the through-wall dimensionh in Fig. 1, sketch (b) of the subsurface indication.C-4(2) Multiple Flaws(a) Discontinuousflawsthatareorientedprimar-ily in parallel planes shall be considered to lie in a singleplaneifthedistancebetweentheadjacentpla
24、nesisequalto or less than 13 mm (0.50 in.) or 0.5t, whichever is less.(b) If the space between two flaws aligned alongthe axis of weld is less than the height of the flaw ofgreater height, the two flaws shall be considered a sin-gle flaw.(c) If the space between two flaws aligned in thethrough-thick
25、ness dimension is less than the height ofthe flaw of greater height, the two flaws shall be consid-ered a single flaw.(h) Flaw Acceptance Criteria. Flaws shall be evaluatedagainst the applicable acceptance criteria of Table 1 orTable 2, except that flaw length (H5129) shall not exceed 4t,regardless
26、of flaw height (h) or the calculated aspectratio.ASME B31.3 CASESFig. 1 Surface and Subsurface Indications(c) Subsurface Flaw(a) Surface Flaw (b) Surface FlawS 0.5hS Shhht ttC-5ASME B31.3 CASESTable 1 Acceptance Criteria for Surface FlawsMaximum h/t for Weld ThicknessAspect Ratio, 25 mm to 64 mm 100
27、 mm to 300 mmh/H5129 (1.0 in. to 2.5 in.) (3.9 in. to 11.8 in.)0.00 0.031 0.0190.05 0.033 0.0200.10 0.036 0.0220.15 0.041 0.0250.20 0.047 0.0280.25 0.055 0.0330.30 0.064 0.0380.35 0.074 0.0440.40 0.083 0.0500.45 0.085 0.0510.50 0.087 0.052GENERAL NOTES:(a) t p thickness of the weld excluding any all
28、owable reinforce-ment. For a butt joint joining two members having differentthicknesses at the joint, t is the thinner of the two thicknessesjoined. If a full penetration weld includes a fillet weld, theeffective throat dimension of the fillet weld shall be includedin t.(b) Aspect ratio (h/H5129) us
29、ed may be determined by rounding thecalculated h/H5129 down to the nearest 0.05 increment valuewithin the column, or by linear interpolation.(c) For intermediate thickness t weld thicknesses between 64 mmand 100 mm (2.5 in. and 3.9 in.), linear interpolation isrequired to obtain h/t values.Table 2 A
30、cceptance Criteria for Subsurface FlawsMaximum h/t for Weld ThicknessAspect Ratio, 25 mm to 64 mm 100 mm to 300 mmh/H5129 (1.0 in. to 2.5 in.) (3.9 in. to 11.8 in.)0.00 0.068 0.0400.10 0.076 0.0440.20 0.086 0.0500.30 0.098 0.0580.40 0.114 0.0660.50 0.132 0.0760.60 0.156 0.0880.70 0.180 0.1020.80 0.2
31、10 0.1160.90 0.246 0.1341.00 0.286 0.152GENERAL NOTES:(a) t p thickness of the weld excluding any allowable reinforce-ment. For a butt joint joining two members having differentthicknesses at the joint, t is the thinner of the two thicknessesjoined. If a full penetration weld includes a fillet weld,
32、 theeffective throat dimension of the fillet weld shall be includedin t.(b) Aspect ratio (h/H5129) used may be determined by rounding thecalculated h/H5129 down to the nearest 0.05 increment valuewithin the column, or by linear interpolation.(c) For intermediate thickness t weld thicknesses between
33、64 mmand 100 mm (2.5 in. and 3.9 in.), linear interpolation isrequired to obtain h/t values.C-6ASME B31.3 CASESB31 CASE 185Use of Standard Helium Leak Test for a Vacuum-Only Piping System (Para. 345)Approval Date: December 22, 2009Inquiry: Under what circumstances does ASME B31.3permit the use of he
34、lium mass spectrometer leak testsperformed under a vacuum as a substitute for the leaktest requirements specified in ASME B31.3, para. 345?Reply: In the opinion of the Committee, the qualifiedheliumleaktestsundervacuumconditionsintheASMEBPV Code, Section V, Article 10, Appendices V and IXare accepta
35、ble substitutes for the testing requirementsidentified in para. 345 of ASME B31.3, provided thefollowing conditions are met:(a) The piping system is expected to operate onlyunder vacuum (i.e., subatmospheric pressure)conditions.(b) Any leakage into the piping system that couldresult in an internal r
36、eaction (e.g., combustion or explo-sion)thatincreasesthepressureaboveatmosphericshallbe prevented.(c) All system joints and connections shall be leaktested. Piping welds and joints to be tested shall beuninsulated and exposed, and shall not be primed,painted, or otherwise coated.(d) Helium leak test
37、ing is performed at vacuum con-ditions sufficient for the mass spectrometer helium leaktests of ASME BPV Code, Section V, Article 10,Appendices V and IX, or at pressures below 10 mbarabsolute (less than 1% of atmospheric pressure), which-ever is lower.C-7(e) ASME B31.3, para. 345.2 applies, except f
38、or theminimum “10 min” leak test period, the leak test pres-sure requirements, and the limitation of the need foraccess for jacketed piping to “visual access.” Paragraph345.3 also applies, except for the leak test pressurerequirements. All other inspection, examination, andrecords requirements of AS
39、ME B31.3 Chapter VI muststill be satisfied (i.e., paras. 340, 341, 342, 343, 344,and 346).(f) Written procedures shall be qualified in accor-dance with ASME BPV Code, Section V, Article 10.(g) Testpersonnelshallhavetrainingandcertificationconsistent with ASME B31.3, para. 342.(h) Test reports, inclu
40、ding records of personnel quali-fications, shall meet the requirements of ASME BPVCode, Section V, Article 10, para. T-1091 and shall beretained for at least 5 yr.(i) Options of the ASME BPV Code, Section V,Article10testmethodsthatallowtheengineeringdesigntomodifyspecifiedrequirementsoftheAppendixVa
41、ndAppendix IX test methods (such as acceptability limitsfor system leak tightness) may only be exercised so asto make these requirements more sensitive or moreconservative.(j) The use of the vacuum leak test instead of thepressurized leak test of ASME B31.3, para. 345 shall bespecifiedintheengineeri
42、ngdesignandshallbeacceptedby the owner.ASME B31.3 CASESB31 CASE 188Minimum Hydrostatic Test Pressure for ASME B31.3, Chapter IX (Para. K345.4.2)Approval Date: June 9, 2014 (published only on ASME Web page)Annulment Date: February 27, 2015Reason for Annulment: Code Case was incorporated into the Code
43、C-8ASME B31.3 CASESB31 CASE 191Cu13Zn1.1NiSiAl Alloy Seamless Pipe and TubeApproval Date: January 21, 2015Inquiry: May precipitation-hardened (temperdesignation TF00) Cu13Zn1.1NiSiAl alloy(UNS No. C69100) seamless pipe and tube conformingto the requirements of ASTM B706-00 (R2011) be usedunder the r
44、ules of ASME B31.3?Reply: Yes, with the following provisions:(a) The maximum allowable stress values for thematerial shall be those given in Table 1.(b) Welded and brazed construction is not permitted.(c) The maximum use temperature shall be204C (400F).(d) Certification tothe ASTMB706-00 (R2011)spec
45、ifi-cation requirements shall be mandatory.C-9Table 1 Maximum Allowable Stress ValuesFor Metal For MetalTemperature TemperatureNot Exceeding, Stress, Not Exceeding, Stress,C MPa F ksi40 138 100 20.065 138 150 20.0100 138 200 20.0125 138 250 20.0150 138 300 20.0175 137 350 19.9200 135 400 19.5225 Not
46、e (1) 132 . . . . . .NOTE:(1) The maximum use temperature for this alloy is 204C (400F).The value listed at 225C is provided for interpolationpurposes only.ASME B31.3 CASESB31 CASE 193Cu5.5Zn4Si Casting Alloy UNS No. C87600Approval Date: October 9, 2014Inquiry: May Cu5.5Zn4Si casting alloyUNS No. C8
47、7600 conforming to the requirements ofASTM B584 be used for construction under the rules ofASME B31.3?Reply: Yes, with the following provisions:(a) The basic allowable stress values for the materialshall be those given in Table 1. A casting quality factor,Ec, needs to be applied.(b) The maximum use
48、temperature shall be177C (350F).(d) Separateweldprocedureandperformancequalifi-cations shall apply to this material. The welding proce-dure qualifications shall be in accordance with ASMESection IX.C-10Table 1 Basic Allowable Stress ValuesFor Metal For MetalTemperature TemperatureNot Exceeding, Stress, Not Exceeding, Stress,C MPa F ksi40 138 100 20.065 138 150 20.0100 138 200 20.0125 138 250 20.0150 138 300 20.0175 138 350 20.0200 Note (1) 137 . . . . . .NOTE:(1) The maximum use temperature for this alloy is 177C (350F).The value listed at 200C is provided for interpolationpurposes only.
