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

Interpretation Response #PI-04-0101 ([Dominion Transmission, Inc.] [Mr. Martin C. Schwoeble])

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

Interpretation Response Details

Response Publish Date:

Company Name: Dominion Transmission, Inc.

Individual Name: Mr. Martin C. Schwoeble

Location State: WV Country: US

View the Interpretation Document

Response text:


U.S. Department of Transportation
Research and Special Programs Administration
400 Seventh Street, S.W.
Washington, D.C 20590

January 22, 2004

Mr. Martin C. Schwoeble
Pipeline Integrity Compliance Specialist
Dominion Transmission, Inc.
445 West Main Street
Clarksburg, WV 26301

Dear Mr. Schwoeble:

This is in response to your letter of November 3, 2003, in which you request an interpretation of the Federal gas pipeline safety regulation at 49 CFR 192.739, Pressure Limiting and Regulating Stations: Inspections and Testing. The question arises from small regulators on the Dominion Transmission, Inc. (DTI) system that provides protection for operating, or end-use, equipment. These types of regulators are installed by the manufacturer of the equipment and are not intended to be inspectible by pipeline operators.

Section 192.701, Scope, notes the Subpart M "prescribes minimum requirements for maintenance of pipeline facilities." Section 192.739 must be read in cognizance of this scope statement. It is clear that § 192.739 is intended to address inspection and testing of pressure limiting and regulating stations that are necessary to maintain safe pressures on the pipeline facility, not on end-use equipment.

This is consistent with the June 28, 1988, interpretation letter cited in your letter. In that interpretation, we note that a regulator subject to § 192.739 would have to fall within the definition of "pressure limiting station" or "pressure regulatory station" as these terms are defined in the ASME B31.8 standard. Under these definitions, it is clear that any regulator serving a downstream piping is a pressure regulating station and is subject to inspection and testing in accordance with § 192.739. Conversely, a regulator that is NOT intended to protect a downstream piping, but rather serves only to protect end-use equipment, such as a compressor, would not be subject to § 192.739.

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
192.701 Scope