Interpretation Response #PI-10-0013
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
November 18, 2010
Mr. Raymond N. Burke
Executive Vice President and COO
6955 High Life Drive
Houston, TX. 77066
Dear Mr. Burke:
In a letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA) dated April 22, 2010, you requested an interpretation of the Federal Pipeline Safety Regulations relating to pipe repairs at 49 CFR §§ 192.309(b), 192.485(a), 192.487(a), 192.713(a)(2) and 192.717(b)(5) and 49 CFR § 195.585(a)(2). You noted that these regulations were amended in 1999 to allow alternative repair of unacceptable damages, dents, imperfections, corrosion, and leaks ".by a method that reliable engineering tests and analyses show can permanently restore the serviceability of the pipe."
You requested information from PHMSA on how the gas and hazardous liquid pipeline safety regulations address the following questions:
1. Do these regulations limit the number of discrete applications or the length of application of alternative repair systems?
2. Can alternative repair systems be used to increase the pressure capacity of a span of pipeline above the original maximum operating pressure in response to revised operating demands?
3. Can alternative repair systems be used to address the need to lower stress levels in the base pipe in response to a change in class location or other revised operating conditions?
Our responses to your questions are as follows:
Response 1: The regulations do not prescribe a particular limit to the number of discrete applications of an alternative repair method. The engineering test data for the material to be used must clearly demonstrate that the alternative repair method will restore the original design strength of the pipe, but will also perform in the pipeline environment in which it is installed, including withstanding secondary stresses of loading, pipe movement, soil movement, and external loads, for the length of service for which it is intended. While the 1999 rule (64 FR 69660, December 14, 1999) allows alternative repair methods for individual repairs on corroded or damaged steel pipe in natural gas pipelines or corroded steel pipe in hazardous liquid pipelines where appropriate, an operator of a pipe joint having sufficient defects should carefully consider all reliable methods of repair before installing an excessive number of alternative repairs.
Response 2: No. The regulations require pipeline operators to repair their pipelines as necessary to maintain safety and serviceability. No repair method can be used to increase the original design strength or the pressure of a segment of pipeline above the established maximum operating pressure.
Response 3: No. A change in Class Location is not a repair issue. The stress level and maximum operating pressure of a given section of pipe is based on the original material and design specifications, not the material used to repair the pipe. Therefore, operators must continue to follow the requirements of §§ 192.609 and 192.611 to confirm or revise the MAOP as necessary upon a change in Class Location, regardless of whether an alternative repair method was used to perform a repair.
I hope that this information is helpful to you. If I can be of further assistance, please contact me at (202) 366-4046.
John A. Gale
Director, Office of Standards and Rulemaking
|§ 195.585||What must I do to correct corroded pipe?|