{"operation":"document","citation":"PI-77-008","title":"Metallurgical Consultants, Inc. — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1977-02-14","effective_on":null,"summary":"PI-77-008 response to Metallurgical Consultants, Inc. concerning 195.1.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-008.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-008.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-008","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1977/PI77008.pdf","body":"<<<PAGE 1>>>\n\nFebruary 14, 1977\nAnswer: Mr. T. V. Bruno\nMetallurgical Consultants, Inc.\nP.O. Box 88046\nHouston, TX 77004\nDear Mr. Bruno:\nThis is in reply to your letter of July 30, 1976, requesting an\ninterpretation of the requirements of 49 CFR Part 195,\n\"Transportation of Liquids by Pipeline,\" relating to the length\nof allowable internal undercutting of pipeline welds.\nQuestion: What is the limit of any individual length of\nundercutting?\nQuestion: Is there a limit of length of undercutting in any given\ncontinuous length of weld (e.g., 12 inches, 1/6 the\ntotal weld length, 8 percent of the total weld length)\nand if so, what is the limit?\nIn regard to the above two questions, Part 195 has\nincorporated by reference API Standard 1104 for standards of\nacceptability for welding. Subsection 6.9, Undercutting, of that\nstandard prescribes the limits of undercut. As stated in that\nstandard, where depth of undercut is between 1/64 inch and 1/32\ninch, the length of any continuous undercut should not exceed 2\ninches or 1/6 the length of the specific weld, whichever is\nsmaller.\nAnswer: Consultation with Mr. R. B. Gwinn, Secretary, API-AGA\nJoint Committee on Oil and Gas Pipe Line Field Welding\nPractices, had indicated that this requirement as\nspecified in the 13th edition of API Standard 1104 is\nin error. Mr. Gwinn has advised that this matter would\nbe corrected in the 14th edition soon to be published\nand that for undercut depth between 1/64 inch and 1/32\ninch the limitation for undercutting length will be 2\ninches in a continuous weld length of 12 inches or 1/6\nof the length, whichever is smaller.\nQuestion: Does Subsection 6.8 of API Standard 1104 include\nundercutting in determining accumulation of\ndiscontinuities?\nThe intent of Subsection 6.8 of API Standard 1104 is\nnot only to exclude high-low condition but also undercutting in\ndetermining accumulation of discontinuities. We have been\nadvised that API will also revise this section in the 14th\nedition of 1104 to clarify this intent.\ndal\\195\\0\\77-02-14\n1\n\n<<<PAGE 2>>>\n\nUpon receipt of this new edition, OPSO will analyze its\ncontent and proceed to determine if it is appropriate\nfor incorporation by reference in OPSO's regulations.\nI trust that this adequately responds to your inquiry.\nSincerely,\nCesar DeLeon\nActing Director\nOffice of Pipeline\nSafety Operations\ndal\\195\\0\\77-02-14\n2\n\n<<<PAGE 3>>>\n\nJuly 30, 1976\nRef: 476-76-2303\nSubj: Interpretation of\n49CFR195\nMr. Cesar DeLeon\nOffice of Pipeline Safety Operations\nDepartment of Transportation\nMaterials Transportation Bureau\nWashington, D.C. 20590\nDear Mr. DeLeon:\nThe purpose of this letter is t o request an official\ninterpretation of the requirements of 49 CFR Part 195 relating to\nthe length of allowable internal undercutting of pipeline girth\nwelds.\nAs revised on October 1, 1975, paragraph 195.228\napplies the standards of acceptability of subsection 6.9 of the\n1973 edition of API Standard 1104 to undercutting only if the\nundercutting is measured visually on each girth weld of the same\ndiameter. There is no specific statement concerning what\nstandards apply if undercutting is not measured visually.\nIf undercutting is measured only by radiography, I\npresume the only criterion of acceptability is length of\nundercutting. Subsection 6.9 of the 1971 edition of API Standard\n1104 states:\n\"Undercutting adjacent to the root bead on the inside\nof the pipe shall not exceed 2 in. in length, or 1/6 of\nthe length of the weld, whichever is smaller.\"\nAt least two interpretations have been applied to this statement.\nOne interpretation is that it limits the accumulated length of\nall undercutting to 2 inches or 1/6 the length of the weld,\nwhichever is smaller; the other is that it limits any individual\noccurrence of undercutting to 2 inches or 1/6 the length of the\nweld with no limit on accumulated length.\nAnother subsection of API Standard 1104 that may relate\nto undercutting, subsection 6.8, is also subject to more than one\ninterpretation. Subsection 6.8 is the same in both the 1971 and\n1973 editions of API Standard 1104 and states:\n\"Excluding high-low condition, any accumulation of\ndiscontinuities having a total length of more than 2\nin. in a continuous weld length of 12-in. or more than\n8 percent of a continuous weld length if the total weld\ndal\\195\\0\\77-02-14\n3\n\n<<<PAGE 4>>>\n\nlength is less than 12-in. is unacceptable. Any\n- 2 -\naccumulation of discontinuities which total more than 8\npercent of the weld length associated with an entire\njoint is unacceptable.\"\nSome people have interpreted this statement as including\nundercutting in determining the allowable length of accumulated\ndiscontinuities. Others, however, have reasoned that since the\nsubsection on undercutting, (6.9), apparently was deliberately\nplaced after the subsection on accumulation of discontinuities,\n(6.8), while subsections covering other discontinuities were\nplaced before it, the subsection on accumulation of\ndiscontinuities was not intended to apply to undercutting.\nIn view of the above considerations, I would appreciate\nan official interpretation from OPSO of the requirements of 49\nCFR 195 pertaining to allowable length of undercutting determined\nby radiography, specifically:\n1. What is the limit of any individual length of\nundercutting?\n2. Is there a limit of length of undercutting in any\ngiven continuous length of weld\n(e.g. 12 inches, 1/6 the total weld length, 8\npercent of the total weld length) and if so, what\nis the limit?\n3. Does subsection 6.8 of API Standard 1104 include\nundercutting in determining accumulation of discontinuities?\nWe are currently involved in several pipeline pro jects\nthat must meet federal requirements and would appreciate an early\nreply.\nVery truly yours,\nT. V. Bruno\ndal\\195\\0\\77-02-14\n4","truncated":false,"body_characters":5763}