{"operation":"document","citation":"PI-78-017","title":"various — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1978-06-20","effective_on":null,"summary":"PI-78-017 response to various concerning 192.453.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-78-017.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-78-017.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-78-017","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1978/PI78017.pdf","body":"<<<PAGE 1>>>\n\nJune 20, 1978\nMr. Robert Steffan, Chairman Mr. M.J. Schiff, Director\nSouthern California Cathodic Los Angeles Section\nProtection Committee National Association of\nNational Association of Corrosion Engineers\nCorrosion Engineers P.O. Box 1499\nP.O. Box 1499 Houston, Texas 77001\nHouston, Texas 77001\nGentlemen:\nThis responds to your letter of April 19, 1978, regarding your assertion that some of the\ncorrosion contractors are not qualified and are doing substandard corrosion work for master\nmeter system operators trying to comply with the Federal pipeline safety standards.\nYou ask what enforcement is available from Federal and State agencies. You further inquire if it\nis practical to require persons designing and/or installing corrosion control systems to accept\nsome legal responsibility for their work.\nThe Federal standard (192.453) require the operator to \"...establish procedures to implement the\nrequirements of this subpart\" and that \"...the design, installation, and maintenance of cathodic\nprotection systems must be carried out, by or under the direction of a person qualified by\nexperience and training in pipeline corrosion control methods.\" This Office has jurisdictional\nauthority over operators of natural gas pipeline systems under the Natural Gas Pipeline Safety Act\nof 1968 and, therefore, our surveillance and enforcement program is directed toward operators to\nassure that they comply with the Federal gas pipeline safety standards. Since our authority does\nnot extend to corrosion contractors designing and installing cathodic protection for such\noperators, we cannot place requirements on such contractors. This is not to say that operators\nand corrosion contractors cannot enter into contractual relationships that place a legal\nresponsibility on the contractor for the adequacy of his corrosion work. Such contractual\nrelationships would not alter the legal relationship between this Office and the operator, but it\ncould establish the basis for legal actions between the operator and contractor.\nThe Office of Operations and Enforcement has a Regional Office in Burlingame, California, that is\nresponsible for inspecting operators and assuring compliance with the regulations. Because of the\nlimited staff, their primary inspection efforts are aimed\nat distribution systems and, to a lesser degree, master meter systems.\nThank you for your interest in matters of pipeline safety.\ndal\\192\\453\\78-06-20\n1\n\n<<<PAGE 2>>>\n\nSincerely,\n\\signed\\\nRobert L. Paullin\nAssociate Director for\nOperations & Enforcement\nMaterials Transportation Bureau\ndal\\192\\453\\78-06-20\n2\n\n<<<PAGE 3>>>\n\nLOS ANGELES SECTION\nApril 19, 1978\nU.S. Department of Transportation\nMaterials Transportation Bureau\nWashington, D.C. 20590\nAttention: Cesar DeLeon, Acting Director\nOffice of Pipeline Safety Operation\nReference: Cathodic Protection of Pipelines\nGentlemen:\nAs officers of the Los Angeles Section of the National Association of Corrosion Engineers and of\nthe Southern California Cathodic Protection Committee, we have been requested to obtain\ninformation from you regarding substandard work in the application of cathodic protection to\ncontrol corrosion on underground gas lines.\nThe Federal Pipeline Safety Act of 1968 required that cathodic protection be applied to\nunderground gas lines subject to active corrosion which might pose a hazard to the public safety.\nInterpretation of this act to include master meter operations, such as mobile home parks, has\nresulted in many new companies being formed to design and install cathodic protection for such\napplications.\nThe federal law states that such work must be done \"by, or under the direction of a person\nqualified by experience and training in pipeline corrosion control methods\". The attached\nquotations from cathodic protection survey reports and photograph of an anode installation\ndemonstrate that some of the contractors are not qualified to do this work, and, in fact, are\nactually increasing the safety hazards. It is apparent that Federal and State laws are being broken.\ndal\\192\\453\\78-06-20\n3\n\n<<<PAGE 4>>>\n\nWe recognize that code violations can be reported to contractors' licensing boards. This,\nhowever, does not prevent incompetent contractors from operating. We would like to know if\nand what enforcement is available from Federal and State Agencies. How and from whom should\nit be obtained?\nIs it practical to require that the person qualified to design and/or install systems sign reports and\naccept some legal responsibility for their work.\nVery truly yours,\n\\signed\\ \\signed\\ _\nRobert Steffan, Chairman M.J. Schiff, Director\nSouthern California Los Angeles Section\nCathodic Protection Committee National Association of Corrosion\nEngineers\nAttachment\nCompany B\nINTRODUCTION\nUnderground gas leaks may be undetectable when the odor is filtered out by the soil.\nUnderground gas leaks often migrate and collect in or under structures creating an explosive\nhazard. Underground gas leaks are primarily caused by corrosion. Our gas leak survey and\ncorrosion test was performed to determine whether pipes are now leaking and whether the pipes\nare in a corrosive environment and thus likely to develop future leaks.\nThe Pipeline Safety Act requires among other things, that gas distributors survey to locate\nand classify gas leaks according to hazard. It further requires that gas distributors either establish\nthat there is no corrosion or install equipment which will minimize corrosion.\ndal\\192\\453\\78-06-20\n4\n\n<<<PAGE 5>>>\n\nBecause pipes may be corroding at one location and not corroding a few feet away, it is\neconomically impractical to dig enough trenches and holes to visually examine all areas and\ndetermine they are not corroding. Thus corrosion engineers use electrical tests to determine (a)\nwhether soil conditions are of the type which promote corrosion and (b) whether corrosive\nelectrical currents may be flowing in the underground piping.\npersonnel surveyed your mobile home park and performed tests which usually\nyield an accurate estimate of the size and type of corrosion control installation needed to protect\nunderground piping.\nOur leak report, describing the leaks found is included here as Appendix I. Appendix II\nreports our measurements of soil resistivity and pipe-to-soil potentials at various points within the\npark.\nIn the pages which follow we report our survey findings and conclusion. We also\nrecommend action for you to take in order to lengthen your pipe life and satisfy Federal safety\nregulations.\nFINDINGS\nLEAKS\nLeaks are detailed, listed and graded in Appendix I. Grade 1 leaks are hazardous and\nmust be cleared immediately (You have already been notified, if you have any). Grade 2 leaks are\npotentially hazardous and should be repaired within 1 year according to the Department of\nTransportation requirements. Grade 3 leaks are non-hazardous and must either be repaired or\nmonitored annually.\nSmith & Dension surveyors found:\ndal\\192\\453\\78-06-20\n5\n\n<<<PAGE 6>>>\n\n0 Grade 1 Leaks\n0 Grade 2 Leaks\n0 Grade 3 Leaks\nCATHODIC PROTECTION\nOur survey showed that voltages measured between gas pipes and surrounding soil varied\nat various points in the park (see Appendix II). The maximum voltage variation measured was\n.150 volts. This is one indicator of the flow of corrosion currents. The highest voltage measured\nwas only .600 volts. This value is absolutely smaller than the 0.850 volts needed to provide\nprotection.\nSOIL RESISTIVITY\nSoil resistivity was measured. The measured resistivity was 5000 ohm/cm3. Resistivities\nbelow 3000 ohm/cm3 coupled with significant variations in pipe-to-pipe potentials indicate a hot\nsoil; that is, a soil which promotes rapid corrosion. With higher values of resistivity, corrosion\nproceeds more slowly.\nISOLATION\nOur tests indicate that your pipeline system is not electrically insulated from the gas utility\ndistribution system.\ndal\\192\\453\\78-06-20\n6\n\n<<<PAGE 7>>>\n\nCONCLUSION & RECOMMENDATIONS\nPIPELINE CONDITIONS\nLow and variable pipe-to-soil potentials and a relatively low soil resistivity indicate that\nthe soil is corrosive, that actual corrosion currents are flowing from the pipes into the ground, and\nthat a cathodic protection installation is required to inhibit active corrosion.\nNEED FOR PROTECTION\nInstalling a cathodic protection system will increase the life of your pipe and reduce the\nleaks and the cost of repairs in future years. Further, it will bring your gas distribution system\nwithin full compliance of the Pipeline Safety Act of 1968 and should thus reduce your liability in\nthe case of an accident. At the same time, you can also protect your metal water pipes. Water\nsystem electrolysis though less dangerous than gas line corrosion and not required by law, is\nequally costly to repair. Further, protecting both sets of pipes at the same time avoids the costly\neffort of inserting an insulating coupling in the riser at each coach and digging up the gas water\npipes and separating them wherever they are in contact.\nWe have calculated that the amount of power required to protect both your gas piping and\nyour water is about 100 watts. This power can most economically be obtained from small\nrectifiers connected to your powerline.\ndal\\192\\453\\78-06-20\n7\n\n<<<PAGE 8>>>\n\nPROPOSAL\nINSTALLATION\nThe cathodic protection installation will comprise 6 large graphite anodes buried in the\nground and 1 transformer rectifiers power supplies connected so as to maintain your pipes at a\nnegative potential higher than .850 volts. This potential will cause current to flow from the anode\nbed to your pipe, thereby inhibiting the ion corrosion now occurring. will excavate, back\nfill, resurface, install and wire the system required to cathodically protect your pipes and restore\nyour property to its original condition.\nThe transformer/rectifier will be mounted on an appropriate wall or post and wired to your\nAC power line. All components of the system are designed for a life of 20 years. Maintenance\nand monitoring instrumentation is built into the rectifier unit.\nWARRANTEE\ninstallations are completely guaranteed for a period of 1 year against defects in\nmaterials and workmanship. Follow up tests will be made at our expense within 1 year from date\nof installation completion to assure adequate performance.\nREPORTS\nWe will prepare and submit in a manual the following plans needed for operating your\ndistribution system in full compliance with the Pipeline Safety Act of 1968:\n1) Operating plan\n2) Maintenance plan\n3) Emergency plan\nPRICE\nThe total price is $4,747.00 subject to the following conditions:\n1) Sewer pipe is non-metallic.\n2) No other underground metallic structures interfere influenced by the current flowing from the anode bed.\nwith, or are\ndal\\192\\453\\78-06-20\n8\n\n<<<PAGE 9>>>\n\n3) Rock, if any, lies deeper than 8 feet below the where anodes are to be buried.\n4) Screwed pipe joints if any, are not so rusted that soil surface in areas\nthey fail\nTERMS\n30% with authorization to proceed.\n70% when installation and test are complete.\nSCHEDULE\nWe will schedule your project within 30 days after you authorize us to proceed. Normal\ninstallation time is five working days: Two days for excavating installation and refill and three\ndays for test and adjustment. In subsequent weeks we will revisit the park as often as necessary\nfor inspection and minor adjustments to compensate for gradual polarization which modifies\nsystem drains as the voltages and currents equalize through the system. We will also notify you of\nany pre-existing corrosion we discover as they are revealed by corrosion scale loosening.\nThis proposal is valid for 30 days. To authorize us to proceed please sign below and\nreturn with an advance payment of 30%.\nFor: For:\nContractor's License:\nSigned: _\n_\n_\nPresident\nDate: Signed: _\nDate: _\nAttachment\ndal\\192\\453\\78-06-20\n9\n\n<<<PAGE 10>>>\n\nCOMPLETE CORROSION DATA\npipe-to-soil potential reading\nlocation reading (dc volts)\n22 .53\n7 .45\n12 .55\n1 .51\n25 .6\n29 .52\nSoils resistivity Measured in ohm/cm3\ndepth reading (ohm/cm3)\n8 ft. 5000\ndal\\192\\453\\78-06-20\n10","truncated":false,"body_characters":12074}