{"operation":"document","citation":"PI-05-0102","title":"City of Mesa — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2005-11-09","effective_on":null,"summary":"PI-05-0102 response to City of Mesa concerning 192.463.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-05-0102.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-05-0102.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-05-0102","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/2005/g05-11-09_Paulus_192.463-lmxs.pdf","body":"<<<PAGE 1>>>\n\nPI-05-0102\nNovember 9, 2005\nMr. Gerald Paulus\nGas Division Director\nCity of Mesa\n640 N. Mesa Drive\nMesa, AZ 85211-1466\nDear Mr. Paulus:\nIn your letter dated August 10, 2004, you requested an interpretation of 49 CFR 192.465(a) External corrosion\ncontrol: Monitoring, regarding steel service risers insta1lled on plastic service lines.\nSection 192.465(a) states that each pipeline that is under cathodic protection must, be tested at least once each\ncalendar year, but with intervals not exceeding 15 months, to determine whether the cathodic protection meets the\nrequirements of § 192.463. However, if tests at those intervals are impractical for separately protected short sections\nof mains or transmission lines, not in excess of 100 feet (30 meters), or separately protected service lines, these\npipelines may be surveyed on a sampling basis. At least 10 percent of these protected structures distributed over the\nentire system must be surveyed each calendar year, with a different 10 percent checked each subsequent year, so that\nthe entire system is tested in each 1O-year period.\nYou asked for an interpretation of the term \"separately protected service lines.\" The term, \"separately protected\nservice lines\" refers to a buried or submerged service line that is electrically isolated and cathodically protected from\nother metallic structures.\nYou also asked if separate steel service risers are \"separately protected service lines\" when they are electrically\ninterconnected by a tracer wire and protected by a common current source or distributed anodes. Separate steel\nservice risers that are electrically interconnected and cathodically protected by a common source are not separately\nprotected lines. Therefore, §192.463(a) requires an operator to monitor such pipelines at least once each calendar\nyear, but with intervals not exceeding 15 months, to determine whether the cathodic protection meets the\nrequirements of §192.463.\nThe regulations do not address the specific pipe material, e.g. tracer wire, that an· operator may select to achieve an\nelectrically interconnected pipeline system; however, operators are expected to rely on sound engineering design and\nselect materials that allow them to determine whether the cathodic protection meets the requirements of §192.463.\nIf you have additional questions, please feel free to contact James Reynolds of my staff at (202) 366-2786.\nSincerely,\nFlorence L. Hamn\nDirector of Regulations\nOffice of Pipeline Safety\n\n<<<PAGE 2>>>\n\nCity of Mesa\n640 North Mesa Drive\nP.O. Box 1465\nMesa, Arizona 85211-1465\nAugust 10, 2004\nMs. Stacey Gerard\nAssociate Administrator\nPipeline Safety\nU. S. Department of Transportation\n400 Seventh Street, SW Room 7128\nWashington, DC 20509\nRE: REQUEST FOR WRITTEN INTERPRETATION.\nDear Ms. Gerard:\nThe City of Mesa respectfully requests an interpretation to 49 CFR 192.465 in regards to the monitoring of corrosion\ncontrol on steel service risers, (non-anodeless) which al e installed on plastic service lines.\nBACKGROUND INFORMATION\nThe process of installing non-anodeless steel risers on plastic service lines was a common installation practices for the\nnatural gas industry and the City of Mesa, Arizona, prior to the full-scale use of \"anodeless risers.\" As a result systems\nhave plastic pipelines with steel risers that require cathodic protection. These systems require corrosion protection in\naccordance with 49 CFR 192 Subpart I — Requirements for Corrosion Control. The corrosion control may be provided as\nindividual separate cathodic protection such as a steel riser separately protected by one anode attached directly to the\nriser, or via a distributed cathodic protection system such as an anode or anodes that are electrically\nwired/interconnected and attached to multiple steel risers. In either case these systems must be monitored for cathodic\nprotection in accordant with 49CFR192.465.\nAnother very common example is when a steel service line feeding from a steel gas main was renewed by inserting a\nplastic pipe and tracer wire through the existing steel service line and then electrically interconnecting the wire to the\nsteel main and steel service riser (see Exhibit 2) in order to provide continuity of cathodic protection.\nAs written in, Part 192.465(a):\nEach pipeline that is under cathodic protection must be tested at least once each calendar year, but with\nintervals not exceeding 15 months, to determine whether the cathodic protection meets the requirements of\nPart 192.463. However, if tests at those intervals are impractical for separately protected short sections of\nmains or transmission lines, not in excess of 100 feet (30 meters), or separately protected service lines, these\npipelines may be surveyed on a sampling basis. At least 10 percent, of these protected structures, distributed\nover the entire system must be surveyed each calendar year, with a different 10 percent checked each\nsubsequent year, so that the entire system is tested in each 10-year period.\nIt is believed by the City of Mesa, Arizona that the term \"separately protected steel service lines\" means those service\nlines that have a separate and individual cathodic protection system (a single anode for each riser) which is electrically\nisolated from other underground metallic structures and other cathodically protected systems.\nHowever, when a natural gas pipeline is electrically interconnected and cathodically protected by a common current\nsource as part of a cathodic protection district these pipelines are considered to be a distributed cathodic protection\nsystem. In other words, a pipeline which contains steel risers interconnected via a wire that is (cadmium) welded to the\nservice riser creates a single electrically continuous unit, more commonly referred to as a cathodic protection system.\nThe City of Mesa believes these systems are no longer separately protected short sections or separately protected\n\n<<<PAGE 3>>>\n\nservice lines as defined in 192.465. This would remain true for both natural gas systems comprised of steel, plastic pipe\nor a combination of the two materials (see Exhibit 1).\nREQUEST FOR INTERPRETATION\nConsidering the background information and when an operator of a Natural Gas Distribution System has engineered\ntheir system to be electrically interconnected and cathodically protected via a distributed cathodic system:\n1. Does the term \"separately protected service lines\" (as used in 49 CFR Part 192.465(a)) mean one service riser\ncathodically protected by a single anode and if so, would it also mean multiple service risers that are electrically\ninterconnected by a tracer wire to a common current source within a continuous Cathodic Protection System?\n2. If these separate steel service risers are electrically interconnected by a tracer wire and protected by a common\ncurrent source or distributed anodes, can the operator monitor and test these pipeline systems at least once\neach calendar year, but with intervals not exceeding 1 5 months, to determine whether the cathodic protection\nmeets the requirements of Part 192.463. Or under the circumstances must they be viewed as separately\nprotected service lines, and surveyed on a sampling basis with at least 10 percent of these protected structures,\ndistributed over the entire system, surveyed each calendar year, with a different 10 percent checked each\nsubsequent year, so that every service line is tested in each 10-year period. (See Exhibit 1)\nYour interpretation on these questions are very important to us and we would like to thank you in advance for your\nprompt consideration. If you have any questions please feel free to contact me at 480-644-2872 or by email at:\nGerald.paulus@cityofmesa.orq.\nSincerely,\nGerald Paulus\nGas Division Director\nCity of Mesa, Arizona 640 N. Mesa Drive\nMesa, Arizona 85211-1466\n480-644-2872 Office 480-861-9573 Mobile","truncated":false,"body_characters":7866}