Montana-Dakota Utilities Company — Pipeline Safety Interpretation

Page 1Mr. Tony J. Finneman Corrosion Superintendent Montana-Dakota Utilities Company 400 North Fulton Street Bismarck, North Dakota 58501 Dear Mr. Finneman: Your letter of September 23, 1985, asks the following question relative to 49 CFR 192.465(a): Question: Will permanent potential monitoring test stations, placed throughout a steel gas distribution system which is completely welded (no couplings) and checked on a monthly basis, satisfy the annual "test for cathodic protection" requirement outlined in this section? Your question has two different areas for consideration. These are the frequency of test under §192.465(a) and the use of "permanent potential monitoring test stations" to make adequate tests. The requirement in §192.465(a) that, "Each pipeline that is under cathodic protection must be tested at least once each calendar year, but at intervals not exceeding 15 months, to determine whether the cathodic protection meets the requirements of §192.463," is a minimum requirement. You may conduct these tests more often. The more frequent testing of once a month would comply with the frequency requirement of §192.465(a). Section 192.469 External Corrosion Control: Test stations governs test stations for use under §192.465(a): "Each pipeline under cathodic protection required by this subpart must have sufficient test stations or other contact points for electrical measurement to determine the adequacy of cathodic protection." If in conducting the tests of cathodic protection, you test at sufficient test stations per §192.469 and demonstrate compliance with §192.463, then the testing would also comply with the requirements of §192.465(a). We hope this adequately responds to your question. Sincerely, DB C:\WP51\INTERPRT\192\465\85-10-24 1#

Page 2Richard L. Beam Chief, Pipeline Safety Regulation Division Office of Pipeline Safety DB C:\WP51\INTERPRT\192\465\85-10-24 2#