asme b31.4 interpretation

ASME B31.4 INTERPRETATIONS

ASME B31.4INTERPRETATIONS NO. 9

Replies to Technical InquiriesOctober 7, 2008 Through May 15, 2012

It has been agreed to publish interpretations issued by the B31 Committee concerning B31.4as part of the update service to the Code. The interpretations have been assigned numbers inchronological order. Each interpretation applies either to the latest Edition or Addenda at thetime of issuance of the interpretation or the Edition or Addenda stated in the reply. Subsequentrevisions to the Code may have superseded the reply.These replies are taken verbatim from the original letters, except for a few typographical and

editorial 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 suffix R is presented. In the case wherean interpretation is corrected by Errata, the original interpretation numberwith the suffix E is used.ASME procedures provide for reconsideration of these interpretations when or if additional

information is available that the inquirer believes might affect the interpretation. Further, personsaggrieved by an interpretation may appeal to the cognizant ASME committee or subcommittee.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.For detailed instructions on preparations of technical inquiries to the B31 Committee, refer to

Nonmandatory Appendix A.Interpretations No. 1 was included with ANSI/ASME B31.4c-1986. Interpretations No. 2 was

included with ASME B31.4a-1987. Interpretations No. 3 was included with ASME B31.4a-1991.Interpretations No. 4 was included with ASME B31.4a-1994. Interpretations No. 5 was includedwith ASME B31.4-1998. Interpretations No. 6 was included with B31.4a-2001. Interpretations No. 7was included with ASME B31.4-2002. Interpretations No. 8 was included with ASME B31.4-2009.

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Copyright ASME International Provided by IHS under license with ASME Licensee=BP International/5928366101

Not for Resale, 11/28/2013 06:39:59 MSTNo reproduction or networking permitted without license from IHS

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B31.4Subject Interpretation File No.

Paragraph 423.2.3 and Table 423.1-1, Mandatory Impact Testing . . . . . . . . . . . . . . . 4-89 10-1604Paragraph 434.8, Previously Qualified Welding Procedures . . . . . . . . . . . . . . . . . . . 4-86 09-1450Paragraph A410.1, Pig Launcher/Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-87 10-809Paragraphs 402.3 and 403.2.1, Hoop Stress and Nominal Wall Thickness . . . . . . . 4-88 10-1154

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Interpretation: 4-86

Subject: Paragraph 434.8, Previously Qualified Welding Procedures (ASME B31.4-2006 Edition)

Date Issued: October 20, 2009

File: 09-1450

Question (1): Is it the intention of B31.4-2006, para. 434.8, that the pipeline owner/operatorsupply the contractor with the owner’s pre-qualified Welding Procedure Specification andProcedure Qualification Record for use on a project?

Reply (1): No.

Question (2): Is it acceptable per B31.4 for the contractor to perform welding on a pipeline/metering station using his own previously qualified Welding Procedure Specification if all of theessential variables are the same?

Reply (2): Yes, provided that the procedure is approved by the owner, as per para. 434.8.3(b)(2).


Subject: Paragraph A410.1, Pig Launcher/Receiver

Date Issued: June 7, 2010

File: 10-809

Question: Does any part of a pig launcher/receiver need to be stamped in accordance withSection VIII, Div. 1 or 2?

Reply: No. Please see paras. 404.7.1 and 404.7.3 of B31.4-2009.


Subject: Paragraphs 402.3 and 403.2.1, Hoop Stress and Nominal Wall Thickness(ASME B31.4-2009 Edition)

Date Issued: July 28, 2010

File: 10-1154

Question (1): Should the hoop stress be calculated per para. 402.3 of B31.4-2009?

Reply (1): Yes.

Question (2): Should the nominal wall thickness be calculated per para. 403.2.1?

Reply (2): Yes.

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Subject: Paragraph 423.2.3 and Table 423.1-1, Mandatory Impact Testing (ASME B31.4-2009Edition)

Date Issued: September 29, 2010

File: 10-1604

Question: In B31.4-2009, is impact testing only mandatory for the materials listed under “Pipe”in Table 423.1-1?

Reply: Yes.

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ASME B31.4INTERPRETATIONS NO. 8

Replies to Technical InquiriesJune 12, 2002 Through October 6, 2008

It has been agreed to publish interpretations issued by the B31 Committee concerning B31.4as part of the update service to the Code. The interpretations have been assigned numbers inchronological order. Each interpretation applies either to the latest Edition or Addenda at thetime of issuance of the interpretation or the Edition or Addenda stated in the reply. Subsequentrevisions to the Code may have superseded the reply.

These replies are taken verbatim from the original 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 suffix R is presented. In the case wherean interpretation is corrected by Errata, the original interpretation number with the suffix E is used.

ASME procedures provide for reconsideration of these interpretations when or if additionalinformation is available that the inquirer believes might affect the interpretation. Further, personsaggrieved by an interpretation may appeal to the cognizant ASME committee or subcommittee.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.

For detailed instructions on preparations of technical inquiries to the B31 Committee, refer toNonmandatory Appendix A.

Interpretations No. 1 was included with ANSI/ASME B31.4c-1986. Interpretations No. 2 wasincluded with ASME B31.4a-1987. Interpretations No. 3 was included with ASME B31.4a-1991.Interpretations No. 4 was included with ASME B31.4a-1994. Interpretations No. 5 was includedwith ASME B31.4-1998. Interpretations No. 6 was included with B31.4a-2001. Interpretations No. 7was included with ASME B31.4-2002.

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B31.4Subject Interpretation File No.

400.1.1, Injection Flow Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-84 07-1459402.3.1, Design Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-79 03-331404.1, Pipe Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-76 02-3680404.1.2, Design Factor and Residual Stresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-81 02-3682421.1, 20% SMYS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-77 02-2486421.1 and 423.2.3, Hoop Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-85 08-417423.2.3, Impact Testing A 106. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-83 07-1458434.8.5, NDE Inspection Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-78 02-2487451.6.2, Repairing a Dent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-80 02-3681451.6.2, Defect Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-82 05-1581

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Subject: Pipe Design Conditions (ASME B31.4-1989 Edition)

Date Issued: June 12, 2002

File: 02-3680

Question: Is it right that the equation defined in para. 404.1 (tn p t + A) fully covers thenegative pipe wall thickness tolerances as defined in API 5L; therefore, the minus tolerance aspermitted by API 5L does not have to be deducted from the nominal pipe wall thickness usedfor calculation of allowable internal pressure?

Reply: Yes.


Subject: Paragraphs 421.1, 434.8.5, and 437

Date Issued: December 19, 2002

File: 02-2486

Question (1): Should the reference to operating above 20% SMYS in para. 421.1(d) actuallyreference operating at a hoop stress of more than 20% SMYS?

Reply (1): Yes.

Question (2): Does the reference of hoop stress in paras. 434.8.5(a)(4), 437.1.4(a)(2) and (3),and 437.4.1(a) mean only the circumferential stress due to internal pressure as calculated inpara. 404.1.2?

Reply (2): Yes.


Subject: Paragraph 434.8.5


File: 02-2487

Question (1): Are there NDE inspection requirements in para. 434.8.5(a)(4) for pipelines to beoperated at a hoop stress of 20% or less of SMYS?

Reply (1): No; see para. 436.5 for inspection requirements.

Question (2): Do the requirements for complete inspection of girth welds in the locations orconditions detailed in paras. 434.8.5(a)(4)(a) through (f) apply only for pipelines to be operatedat a hoop stress of more than 20% of SMYS?

Reply (2): Yes.

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Subject: Paragraphs 434.13.4(c) and 451.9(a)


File: 03-331

Question (1): Should the design factor for the use in API 1102 para. 4.8.2, Checks for Fatigue,be the same as the design factor in B31.4 para. 402.3.1?

Reply (1): Yes.

Question (2): Should the references to circumferential stresses and total stress in para. 451.9(a)actually be references to effective stress as per para. 434.13.4(c)?

Reply (2): Yes.


Subject: Paragraph 451.6.2(b)(3)

Date Issued: February 20, 2003

File: 02-3681

Question: Does B31.4 (1998 Ed. as revised) permit repairing a scratch, gouge, or groove in adent by grinding the scratch, gouge, or groove out to a smooth contour and evaluating theresulting metal loss similarly to metal loss from corrosion?

Reply: No.




File: 02-3682

Question: Does the design factor include allowance for residual stresses that may be presentin the pipes manufactured in accordance with API 5L, specifically helical seam submerged arcwelded pipes?

Reply: Yes.

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Subject: Paragraph 451.6.2(a)(7)

Date Issued: January 16, 2006

File: 05-1581

Question (1): For the equation found in para. 451.6.2(a)(7), does the defect length, L, representthe length of the defect measured longitudinally along the pipeline axis or can it be measuredcircumferentially?

Reply (1): No, L cannot be measured circumferentially.

Question (2): If a defect in a pipeline is 3⁄8 in. along the pipeline axis but 14 in. circumferentially,can the equation found in para. 451.6.2(a)(7) be applied using the circumferential length of thedefect to represent the parameter L in the equation?

Reply (2): No, the parameter L remains 3⁄8 in.



Date Issued: January 25, 2008

File: 07-1458

Question: If ASTM A 106 pipe is operating over 7,000 psi (20% of 35,000 psi), shall the materialbe impact tested?

Reply: Yes.


Subject: Injection Flow Lines


File: 07-1459

Question (1): Are flow lines between oilfield injection wells and oilfield injection facilitiesexcluded from the Scope of ASME B31.4?

Reply (1): No.

Question (2): Are flow lines between oil production wells and oilfield separation facilitiesexcluded from the scope of ASME B31.4?

Reply (2): No.


Subject: Paragraphs 421.1(d) and 423.2.3

Date Issued: March 25, 2008

File: 08-417

Question: In paras. 421.1(d) and 423.2.3, does 20% SMYS refer to the hoop stress?

Reply: Yes.

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ASME B31.4

INTERPRETATIONS NO. 5

Replies to Technical Inquiries January 1,1994, Through December 31,1997

It has been agreed to publish intepretations issued by the B31 Committee concerning B31.4 as part of the update service to the Code. The interpretations have been asssigned numbers in chronological order. Each interpretation applies either to the latest Edition or Addenda at the time of issuance of the interpretation or the Edition or Addenda stated in the reply. Subsequent revisions to the Code may have superseded the reply.

These replies are taken verbatim from the original letters, except for a few typographical and editorial corrections made for the purpose of improved clarity. In some instances, a review of the interpretation revealed a need for corrections of a technical nature. In these cases, a revised reply bearing the original interpretation number with the suffix R is presented. In the case where an interpretation is corrected by Errata, the original interpretation number with the suffix E is used.

ASME procedures provide for reconsideration of these interpretations when or if additional information is available which the inquirer believes might affect the interpretation. Further, persons aggrieved by an interpretation may appeal to the cognizant ASME committee or subcommittee. 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.

For detailed instructions on preparations of technical inquiries to the B31 Committee, refer to Appendix B.

Interpretations No. 1 was included with ANSVASME B31.4~-1986. Interpretations No. 2 was included with ASME B31.4a-1987. Interpretations No. 3 was included with ASME B31.4a-1991. Interpretations No. 4 was included with ASME B31.4a-1994.

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B31.4

Subject . 401.2.2, Internal Design Pressure; 402.3, Allowable Stresses and Other

Stress Limits; 404.1.2, Straight Pipe Under Internal Pressure .................... 401.6, Weight Effects; 402.3, Allowable Stresses and Other Stress Limits . . . . . . . . . . . . 406.2.2, Mitered Bends ..................................................... 419.7.3(b), Expansion and Flexibility Analysis; Fig . 419.6.4(c),

Flexibility Factor k and Stress Intensification Factor i .......................... 434.8.6(a), Butt Welds; Fig . 434.8.6(a)-(2), Acceptable Butt

Welded Joint Design for Unequal Wall Thicknesses ........................... 435.5, Auxiliary Liquid Petroleum. Liquid Anhydrous Ammonia,

451.6.2(a)(7), Disposition of Defects .......................................... Certification of a Listed Material to Another Listed Material Specification . . . . . . . . . . . Figure 434.8.6(a)-(2), Acceptable Butt Welded Joint Design

for Unequal Wall Thicknesses. Note (1) ..................................... Fully Welded Partial Encirclement Half Soles in an Oil Pipeline . . . . . . . . . . . . . . . . . . . Mill Certificates; 402. Design Criteria; 436. Inspection ........................... Requirements for Re-converting a Steel Pipeline's Function ....................... Temperature Limitations for Underground Ethylene Pipelines ......................

or Liquid Alcohol Piping .................................................

Interpretation

4-66 4-56 4-60

4-6 I

4-57

4-55 4-65 4-62

4-64 4-59 4-67 4-58 4-63

File No .

B31-97-011 B3 1-93-054 B31-97-007

B3 1-97-008

B3 1-94-032

B31-93-056 B31-97-005 B3 1-94-035

B 3 1 1-95-05 B3 1-97-006 B31 -97-023 831-94-054 B31-94-047

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STD-ASME B31.V I N T N O = 5-ENGL m 0757b70 Ob09314 723 m

831.4 Interpretations No. 5 4-55. 4-56


Subject: ASME B31.4-1992 Edition, Para. 435.5, Auxiliary Liquid Petroleum, Liquid Anhydrous Ammonia, or Liquid Alcohol Piping

Date Issued: May 3 1, 1994

File: B3 1-93-056

Question: In accordance with ASME B31.4, para. 434.5(a), does B31.4 prohibit a manufacturer of full- encirclement welded split tees from repairing notches, grooves, gouges, and blowouts by welding?

Reply: No.


Subject: ASME B31.4-1992 Edition, Para. 401.6, Weight Effects, Para. 402.3, Allowable Stresses and Other Stress Limits

Date Issued: April 23, 1997

File: B31-93-054

Question: For an exposed submarine pipeline resting on the seafloor and where it can not be conclusively proven that hydrotesting has removed the longitudinal stresses due to pipeline route curvature, should the stress due to curvature be accounted for in the equivalent tensile stress calculation which is required to be less than 09SMYS in the restrained section [para. 402.3.2(c)] and less than 75% of the allowable stress value [para. 402.3.2(d)]?

Reply: Yes.

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STD-ASME B 3 1 - 4 I N T N O - 5-ENGL W 0759b70 Ob07315 BbT W

4-57, 4-58 831.4 Interpretations No. 5


Subject: ASME B31.4-1992 Edition, Para. 434.8.6(a), Butt Welds, Fig. 434.8.6(a)-(2), Acceptable Butt Welded Joint Design for Unequal Wall Thickness


File: B31-94-032

Question (1): Is it permissible to butt weld a weld neck flange made from material with a specified minimum yield strength of 35 ksi (for example, A 105) directly to Grade X60 pipe as long as the pressure class rating of the flange meets the design requirements?

Reply (1): Yes. The inquirer is cautioned to review the requirements of para. 434.8.6 and Fig. 434.8.6(a)-(2).

Question (2): Is it permissible to weld a slip-on flange made from material with a specified minimum yield strength of 35 ksi (for example, A 105) directly to Grade X60 pipe as long as the pressure class rating of the fitting meets the design requirements?

Reply (2): Yes.

Question (3): Is it permissible to weld a fitting made from material with a specified minimum yield strength of 35 ksi (for example, A 105) directly to Grade X60 pipe for all other types of weld joints except butt welds (e.g., as a branch connection attached with a full penetration groove corner joint) as long as the pressure class rating of the fitting meets the design requirements?

Reply (3): Yes.


Subject: ASME B31.4-1992 Edition, Requirements for Reconverting a Steel Pipeline’s Function


File: B31-94-054

Question: Under ASME B31.4-1992 Edition, are there any requirements for reconverting a steel pipeline, originally used for liquid transportation, back to liquid transportation after being used for several years for gas transportation?

Reply: No, there is no requirement under B3 1.4-1992 Edition.

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S T D = A S M E B3L-q I N T N O = 5 - E N G L m 0 7 5 9 b 7 0 O b 0 7 3 L b 7 T b

831.4 Interpretations No. 5 4-59, 4-60. 4-61


Subject: ASME B31.4-1986 Edition, Fully Welded Partial Encirclement Half Soles in an Oil Pipeline


File: B31-97-006

Question: Is the installation of half soles on an X-42 pipeline constructed in 1965 acceptable to ASME B31.4-1986?

Reply: No.


Subject: ASME B31.4-1992 Edition, Para. 406.2.2, Mitered Bends


File: B3 1-97-007

Question (1): What is the basis of para. 406.2.2?

Reply (1): The inquirer is referred to para. 400 for the purpose and principles of the Code.

Question (2): Does the limitation of 20% of the yield apply even if a full analysis has been carried out?

Reply (2): Yes. Refer to para. 400(e).

Question (3): Would a successful finite element analysis of the pup piece be considered acceptable in lieu of compliance with para. 406.2.2?

Reply (3): Yes. Refer to para. 400.


Subject: ASME B31.4-1992 Edition, Para. 419.7.3(b), Expansion and Flexibility Analysis, Fig. 419.6.4(c), Flexibility Factor k and Stress Intensification Factor i


File: B31-97-008

Question: Is the stress intensification factor calculation shown in Fig. 419.6.4(c) for welding tees applicable for extruder outlet headers?

Reply: Figure 419.6.4(c) does not address extruded outlet headers.

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4-62.4-63 831.4 interpretations No. 5


Subject: ASME B31.4-1992 Edition, Certification of a Listed Material to Another Listed Material Specification

Date Issued: August 29, 1997

File: B3 1-94-035

Question: Is it permissible under the requirements of the above mentioned Code for a steel service center/ processor to certify a Listed Material to another Listed Material specification by using the chemical analysis performed by the material manufacturer (the mill) and physical test performed by the service center or the manufacturer and provided all test results, method and process of manufacture, heat treatment, and quality control meet the requirements of material specification in question and meet the requirements of this Code.

Reply: No.


Subject: ASME B3 1.4- 1992 Edition, Temperature Limitations for Underground Ethylene Pipelines


File: B3 1-94-047

Question (la): Do the corresponding chapters (materials, welding, design, installation, and testing) of ASME B31.8 also apply to underground ethylene pipelines?

Reply (la): No. ASME B31.4 is the appropriate Code for ethylene pipelines.

Question (1 b): Except as specified in this Code, are there any extra regulations which should be followed for the safety considerations of ethylene transmission?

Reply (1 b): The ASME B31.4/11 Section Committee cannot respond to questions concerning other regulations.

Question (2): Should cathodic protection measures be taken for underground ethylene pipelines in soil with low resistivity less than 10 R-m?

Reply (2): Yes. Refer to ASME B3 1.4, Chapter VIII.

Question (3): Does ASME B31.4 have temperature limitations for underground ethylene pipeline transmission?

Reply (3): No.

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831.4 Interpretations No.5 4-64


Subject: ASME B31.4-1992 Edition, Fig. 434.8.6(a)-(2), Acceptable Butt Welded Joint Design for Unequal Wall Thicknesses, Note (1)


File: B3 1-95-05 1

Question (1): Is it the intent of the Code that the 3/32 in. dimension shown in Fig. 434.8.6(a)-(2), sketch (a) is a nominal dimension?

Reply (1): Yes.

Question (2): Is the mismatch requirement of sketch (a) met when welding two adjoining pipe ends ordered to API 5L with the same diameter and nominal wall thickness as long as the difference between the maximum and minimum wall thickness does not exceed 3/12 in.?

Reply (2): Yes.

Question (3): Is the mismatch requirement of sketch (a) met when welding two adjoining pipe ends ordered to API 5L having the same diameter and nominal wall thickness if the mismatch (difference between the maximum and minimum wall thickness) exceeds 3/32 in.?

Reply (3): Yes.

Question (4): Is the mismatch requirement of sketch (a) met when welding two adjoining pipe ends ordered to API 5L, having the same nominal diameter but different nominal wall thickness (one pipe is nominally greater than 3/32 in. thicker than the other)?

Reply (4): No. Correction in accordance with sketch (b), (c), or (d) is required.

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4-65 B31.4 Interpretations No. 5


Subject: ASME B31.4-1992 Edition, Para. 45 1.6.2(a)(7), Disposition of Defects


File: B3 1-97-005

Question (1): According to ASME B3 1.4-1992 Edition, para. 451.6.2(a)(7), is the significance of the depth of corrosion pits located in girth or longitudinal welds or related heat affected zones to be evaluated to the same criteria as corrosion pits in the base pipe (¡.e., must be deep enough to reduce the wall thickness below the design thickness less the manufacturing tolerance in order to warrant repair, replacement, or operating pressure reduction)?

Reply (1): Corrosion pit depth in welds is not presently addressed in ASME B31.4-1992 Edition.

Question (2): According to ASME B31.4-1992 Edition, para. 451.6.2(a)(7), is the depth of a corrosion pit located in girth or longitudinal welds or related heat affected zones to be evaluated relative to the nominal pipe wall thickness (Le., ignoring weld reinforcement)? If so, should the corrosion pit depth be measured from the top of the weld reinforcement or from the location where the corrosion pit intersects the extension of the plane of the surface of the pipe?


Question (3): According to ASME B31.4-1992 Edition, para. 45 1.6.2(a)(7), are corrosion pits of significant depth (¡.e., deep enough to reduce the wall thickness below the design thickness less the manufacturing tolerance, but less than 80% of nominal wall thickness) that are located in girth or longitudinal welds or related heat affected zones, cause for line repair, replacement, or Operation at reduced pressure regardless of their length?


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STDeASME B31.9 I N T N O - 5-ENGL m 0757b70 Ob07320 L27 m

831.4 Interpretations No. 5 466,447


Subject: ASME B31.4-1992 Edition, Para. 401.2.2, Internal Design Pressure, Para. 404.1.2, Straight Pipe Under Internal Pressure, Para. 402.3, Allowable Stresses and Other Stress Limits


File: B31-97-011

Question (1): Daes the statement in para. 401.2.2, “Credit may be given for hydrostatic external pressure, in the appropriate manner, in modifying the internal design pressure for use in calculations involving the pressure design of piping components (see para. 404.1.3),” also apply to the formula in para, 404.1.2 for subsea systems?

Reply (1): Yes.

Question (2): May hydrostatic external pressure be accounted for in calculations involving the internal pressure design of piping components?

Reply (2): Yes.

Question (3): Is it possible to incorporate “Maximum Distortional Energy Theory (von Mises Combined Stress)” in para. 402.3?

Reply (3): No.


Subject: ASME B31.4-1992 Edition, Mill Certificates, Para. 402, Design Criteria, Para. 436, Inspection


File: B3 1-97-023

Question: Does the Code require Mill (material) Certificates - chemical composition - for the line pipe and its components to be provided as part of the specification?

Reply: No.

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asme b31.4 interpretation

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