{"operation":"document","citation":"PI-72-0106","title":"Natural Gas Pipeline Company of America — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1972-04-13","effective_on":null,"summary":"PI-72-0106 response to Natural Gas Pipeline Company of America concerning 192.243.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-72-0106.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-72-0106.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-72-0106","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1972/g72-04-13_Barkow_192.234-nlmx.pdf","body":"<<<PAGE 1>>>\n\nPI-72-0106\nApril 13, 1972\nMr. A. G. Barkow\nNatural Gas Pipeline Company of America\n122 South Michigan Ave.\nChicago, Illinois 60603\nDear Mr. Barkow:\nThis is in answer to your letter of March 14, 1972, regarding paperback film for radiography, and the film’s acceptability\nunder the Department’s pipeline safety regulations.\nThere are two sets of Federal pipeline safety regulations which include requirements for the nondestructive testing of\nfield girth welds. One is the gas pipeline safety regulations contained in part 192 of the Code of Federal Regulations (49\nCFR Part 192) which is titled “Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards.”\nThe other is the set of regulations over liquid pipeline carriers engaged in the transportation hazardous materials and\npetroleum in interstate and foreign commerce. These regulations are located in Part 195 of the Code of Federal\nRegulations (49 CFR Part 195) and are titled “Transportation of Liquids by Pipeline.”\nThe gas safety regulations in Paragraph 192.243 (a) require that “nondestructive testing of welds must be performed by\nany process, other than trepanning, that will clearly indicate defects that may affect the integrity of the weld.” This is a\nperformance standard in that no particular process is specified.\nThe liquid safety regulations are also performance oriented concerning the nondestructive testing of welds. Paragraph\n195.234(a) requires that “A weld may be nondestructively tested by any process that will clearly indicate any defects\nthat may affect the integrity of the weld.” The liquid safety regulations also require in Paragraph 195.234(g) that film,\nwhen radiography is used, “must be retained for three years after the line is placed in operation.”\nThe safety goal in welding is to produce a weld that will be free of defects which might impair the structural integrity of\nthe weld. Any nondestructive testing process which will assure that this goal is accomplished by complying with the\nregulations cited above will be acceptable to the Department.\nPlease contact me if I can be of any further assistance in this matter.\nSincerely\nOriginal singed by:\nJoseph C. Caldwell\nDirector\nOffice of Pipeline Safety\n\n<<<PAGE 2>>>\n\nNGPL\nNatural Gas Pipeline Company of America\n122 South Michigan Ave.\nChicago, Illinois 60603\nMarch 14, 1972\nMr. Joseph C. Caldwell\nOffice of Pipeline Safety\nDepartment of Transportation\nWashington, D. C. 20590\nDear Mr. Caldwell:\nRecently, a manufacturer of radiographic film for the pipeline industry has started to market a so called paper back film.\nIt is my understanding that other film producers are likewise planning to market a similar product. This product has been\ntried out by various laboratories and in the field and does produce very satisfactory radiographic film. A section of such\nfilm is attached hereto.\nSome question has risen as to whether this film will be accepted as complying with the requirements of API Standard\n1104 and whether it will be acceptable to the Department of Transportation, Office of Pipeline Safety. As a member of\nAPI Standard 1104 Committee, I have given this matter considerable attention and have in fact, made numerous tests of\nthe product at my laboratory under simulated field conditions on standard size pipe of various diameters. From the\nstandpoint of interpretive possibility, I find that a paper back film is every bit as sharp and as easy to read as the regular\nfilm. This paper back film has many advantages, the chief of which is that it can be read dry within minutes after the\nexposure is made. The real advantage here is that radiography could be held as close to the welding as possible, thus the\nresults of the radiographic examination could be used immediately to take corrective measures, as far as welding is\nconcerned.\nTwo questions in connection with the use of this material are: 1) can paper back film be classified as film? By definition,\nfilm is a transparent material with a thin film of photo sensitive emulsion. Using this definition, of course, paper back\nfilm does not qualify as film. However, if we define film as a negative image of an object, then paper back film will\ncomply. 2) API Standard 1104 requires that radiographic film have a density of 1.5 to 2.5 H & D.\nH & D scale applies only to transparent or translucent objects. Again this requirement does not apply to paper back film.\nOn the other hand, there is also a reflective scale which is just about 1/2 of the H & D scale. Thus, 0.8 on the reflective\nscale is approximately equal to 2.0 on the H & D scale, as far as readability is concerned. Here again we do have an\napparent conflict.\nIt is my personal feeling that since the paper back film is a negative, it can be classified as a film. Also, the H & D density\nrequirement pertains to transmitted light and therefore, is not applicable to paper back film. However, to make these\npoints perfectly clear, I would like to propose a new paragraph to API Standard 1104 to read as follows:\nParagraph 8.10 Paper Based Film\n\"Paper based film may be used providing it will meet all of the requirements of Section 8.0 with the exception of the\ndensity requirement, Paragraph 8.9. Paper based film shall have the same sensitivity, definition and interpretive value as\ntransparent based film\"\nI believe that with this added paragraph, we could use this product without in any way jeopardizing the quality\nrequirements for radiographic examination. Before proposing this addition to API Standard 1104, I would appreciate any\ncomments that you have in this matter. I might state that I have had numerous telephone calls regarding paper back film\nand am of the opinion that there is a great desire to use the film if it will meet the approval of the Office of Pipeline\nSafety.\nAs stated before, there are many advantages in the use of this material, and I can find nothing, as far as the product is\nconcerned, which would in any way deteriorate the interpretation of defects or reduce its interpretive value.\nVery truly yours,\nA.G. Barkow Chairman\nRadiographic Sub-Committee\nAPI Standard 1104","truncated":false,"body_characters":6126}