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Interpretation Response #PI-72-010 ([Gas Pipeline Safety Division] [T. K. Spalding])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Gas Pipeline Safety Division

Individual Name: T. K. Spalding

Location State: WV Country: US

View the Interpretation Document

Response text:

May 9, 1973

Mr. T. K. Spalding, Director

Gas Pipeline Safety Division

State of West Virginia

Public Service Commission

Charleston, West Virginia 25305

Dear Mr. Spalding:

This is in answer to the questions asked in your letter of April 17, 1973.

Question 1. Is cathodic protection required on bare transmission or distribution lines laid prior to August 1, 1971, in areas where corrosion is in progress, as determined by electrical survey or experience, if continuing corrosion would not be detrimental to public safety? Section 192.457(c) seems to have been specifically written to exclude such areas.

Answer. Section 192.457(b) requires, in pertinent part, that bare transmission or distribution lines installed before August 1, 1971, must be cathodically protected by a given date in areas in which active corrosion is found. "Active corrosion" is defined in §192.457(c) to mean continuing corrosion which, unless controlled, could result in a condition that is detrimental to public safety.

The test for applicability of the requirement, therefore, is not whether the corrosion is now detrimental to public safety, but rather whether continuing corrosion could lead to a condition that might later become detrimental. Thus, if the continuing corrosion could at some future time result in a condition that is then detrimental to public safety even though today such condition does not exist, the pipeline is nevertheless subject to the requirement now rather than at a later time. We cannot determine from your description of the given situation that "active corrosion" is not present.

Question 2. How often must electrical surveys be made on pipelines protected by the "hot spotting" method?

Answer. Section 192.465(e) requires each operator to reevaluate its unprotected pipelines at intervals not exceeding three years. The reevaluation is done by electrical survey where practical.

pipeline protected by the "hot spotting" method is an unprotected pipeline for purposes of §192.465 and therefore subject to the three-year reevaluation requirement. The "hot spots," of course, are subject to other monitoring requirements.

If you have further questions in this regard, please contact us.


Joseph C. Caldwell


Office of Pipeline Safety

Regulation Sections

Section Subject
192.457 External corrosion control: Buried or submerged pipelines installed before August 1, 1971