USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #PI-03-0102 ([City of Mesa] [Mr. Michael Comstock])

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

Interpretation Response Details

Response Publish Date:

Company Name: City of Mesa

Individual Name: Mr. Michael Comstock

Location State: AZ Country: US

View the Interpretation Document

Response text:


U.S. Department of Transportation
Research and Special Programs Administration

June 11, 2003

Mr. Michael Comstock
Utility Compliance Coordinator
City of Mesa
640 North Mesa Drive P.O. Box 1466
Mesa, AZ 85211-1466

Dear Mr. Comstock:

This is in response to your September 19, 2001, request for an interpretation of the distribution valve maintenance regulation at 49 CFR 192.747. You ask whether a "gas valve used to control blowing or escaping natural gas becomes a 'Key Valve,' and as a 'Key Valve,' requires special treatment for the life of the valve."

Section 192.747, Valve Maintenance: Distribution Systems, states that "[e]ach valve, the use of which may be necessary for the safe operation of a distribution system, must be checked and serviced at intervals not exceeding 15 months, but at least once each calendar year."

This section addresses the maintenance of valves which may be necessary to safely operate the distribution system and to isolate parts of the system as necessary. In response to this regulation and safe operating practices, the City of Mesa has designated many, but not all, distribution system valves as "Key Valves."

Mere operation of a particular valve during an emergency does not automatically elevate it to "Key Valve" status within the meaning of § 192.747. Many valves may be shut during an emergency, including designated "Key Valves," valves on service lines, valves at the meter assembly, and even some mainline valves not designated as "Key Valves." Not all of these valves, upon investigation, would necessarily be shown to be "necessary for the safe operation of the system."

The question to be addressed is whether a particular valve is necessary on an ongoing basis to safely operate the distribution system. This question must be addressed on a case by case basis by the distribution company and its regulatory agencies. Therefore, a "gas valve used to control blowing or escaping natural gas at an accident site" does not automatically become a "Key Valve."

If you have any further questions about the pipeline safety regulations, please contact me at (202) 366-4565.


Richard D. Huriaux, P.E.
Manager, Regulations
Office of Pipeline Safety

Regulation Sections

Section Subject
192.747 Valve maintenance: Distribution systems