Missouri Public Service Commission — Pipeline Safety Interpretation

Page 1March 20, 1985 Mr. Dale W. Johansen Assistant Manager Missouri Public Service Commission P.O. Box 360 Jefferson City, Missouri 65102 Dear Mr. Johansen: In response to your letter of February 22, 1985, and subsequent discussions on the Missouri PSC enforcement problems concerning 49 CFR Part 192, paragraph 192.619 and related regulations, I offer the following comments: The facts: m The steel distribution pipeline systems were designed for 40 psi. m The systems were tested and qualified for 40 psi at time of installation. m Installation and testing was prior to July 1, 1965. m The system relief valves are sized and set to relieve for 40 psi MAOP. m The systems operated at no higher than 10 psi for the 5 years prior to July 1, 1970. The Operating limitations of concern that are imposed by Part 192 on the gas systems are: m 192.619(a)(3) limits the MAOP of the system to 10 psi. This is also the MAOP permitted by 192.621. m 192.621(a)(5) & (b) requires that the relief valves that will prevent the MAOP from being exceeded, be designed in accordance with 192.195. The problem: In order to have sufficient relief capacity at an MAOP of 10 psi, the operator would incur the expense and effort of replacing the relief valves. or dal\192\619\85-03-20 1#

Page 2The operator would incur the expense and effort of upgrading the system per 192.553 and 192.557 to an MAOP of 40 psi. My staff and I have reviewed the regulations and interpretations relating to the situations described and advise that, based on the facts and conditions previously stated, the operator has three options for action he can take: 1. Waiver - The operator could submit to the Missouri Public Service Commission a request for waiver from 192.619 to permit the MAOP to be established at 40 psi without performing certain requirements specified in Subpart K - Uprating or to permit the existing relief devices to continue in use. In either case, the operator would have to demonstrate why the existing regulation(s) is (are) inappropriate and how the level of safety intended by the regulation(s) will be maintained. If the Missouri Public Service Commission would approve such a waiver request, the approval would be contingent upon MTB's concurrence. This option should not be considered by the Missouri PSC where a compliance case has been initiated. 2. Upgrade the Existing Pipeline Systems - The operator could upgrade the existing piping systems per the requirements of 192.553 and 192.557. These upgrading requirements do provide a sound and practical means to upgrade the MAOP of pipelines that have been operated and maintained in accordance with good procedures such as you indicated the operator claims to have performed. 3. Replace Overpressure Protective Devices - The operator could replace the existing overpressure protective devices with devices that would be capable of protecting the 10 psi MAOP within the limits specified by 49 CFR Part 192, i.e, 192.621(b), 192.195, 192.199, and 192.201. I have enclosed for your information and future guidance, several interpretations relating to the regulations involved in this determination. These interpretations should reinforce and clarify your understanding of the regulations as discussed in your letter and are consistent with our national policy. I would also like to emphasize that 192.557 provides the operator with a practical means of establishing a higher MAOP for pipelines believed to be in an otherwise safe operating condition. The regulations also protect the public by requiring the operator to take steps to assure that safe condition. The requirements are little more than what a prudent operator would do prior to raising the pressure on any pipeline that had been operated at a lower pressure for several years. If you desire any further clarification, please contact Ed Ondak, Frank Fulton, or myself. Thank you for your participation in this pipeline safety program. dal\192\619\85-03-20 2#

Page 3Sincerely, Robert L. Paullin Associate Director for Operations and Enforcement Materials Transportation Bureau Enclosures dal\192\619\85-03-20 3#