Interpretation Response #PI-04-0105 ([Mueller Company - Gas Products Division] [Mr. Connor J. Deering])
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Mueller Company - Gas Products Division
Individual Name: Mr. Connor J. Deering
Location State: IL Country: US
View the Interpretation Document
Response text:
PI-04-0105
U.S. Department of Transportation
Research and Special Programs Administration
400 Seventh St., S.W.
Washington, D.C. 20590
April 20, 2004
Mr. Connor J. Deering
Mueller Company - Gas Products Division
Decatur, IL 62525
Dear Mr. Deering:
This is in response to your e-mail of March 26, 2004, in which you request an interpretation of the provisions of the Federal gas pipeline safety regulations at 49 CFR 192.145, Valves, as it relates to the use of brass valves in gas pipeline systems.
Although the use of brass body valves in gas pipeline systems is not explicitly excluded by the pipeline safety regulations, the pipeline operator must be able to demonstrate how these valves comply with the regulations. This includes a showing that the valves comply with American Petroleum Institute standard API 6D, Specification for Pipeline Valves, or an equivalent standard. The regulations also require the operator to have written procedures for installation and maintenance of brass valves. In addition, where a gas distribution pipeline system is regulated by a state agency, the state is free to be more restrictive, as long as it is not inconsistent with the Federal regulations.
Brass body valves are typically used as shutoff valves on gas service lines. It has been asserted by some suppliers that such valves comply with the requirements of the American National Standards Institute's (ANSI) standard ANSI B16.33, Manually Operated Metallic Gas Valves for Use in Gas Piping Systems up to 125 psig (Sizes 1/2 Through 2). And, you are no doubt aware that the American Society of Mechanical Engineer's standard ASME B31.8, Gas Transmission and Distribution Piping Systems, allows valves manufactured according to ANSI B16.33 or API 6D for use in gas service lines if the valves meet certain other requirements.
In any case, an operator installing a brass body valve would need to ensure that it complies with the rest of the regulations in § 192.145. For example, § 192.145(b)(2)(ii) requires testing of valves to 1.5 times the maximum service rating. This is a more stringent seat test than API 6D (1.5 vs. 1.1). It is not unusual for a regulation to call for compliance with a standard, but to also prescribe additional or more stringent requirements. An operator would need to specify a 1.5 times seat test in their orders to valve manufacturers to comply with the requirements of § 192.145.
In response to your specific questions:
- Does the U.S. Department of Transportation require that natural gas meter valves meet API 6D?
OPS Response: Yes. All valves used in gas distribution and transmission systems must meet the minimum requirements, or equivalent, of standard API 6D.
- Although API 6D has strict material composition requirements, section 382, Composition Limits, states that "all alternate metallic materials shall have compositions with a minimum of 50% by weight of any combination iron, nickel, or cobalt and a maximum of 0.45% by weight of carbon." Does brass meet these requirements?
OPS Response: No.
- Are you aware of an "equivalent" standard that would allow brass as an acceptable material for natural gas meter valves?
OPS Response: Some pipeline operators have cited ANSI B16.33 as an equivalent standard for brass body service line valves. The applicability of any particular standard and its acceptability as an equivalent standard for brass body service line valves would need to be supported by the pipeline operator and reviewed by OPS and state pipeline safety inspectors on a case-by-case basis.
- If brass is not acceptable under API 6D, and no "equivalent" standard exists, is brass an acceptable material for natural gas meter valves?
OPS Response: Brass is not banned from use on natural gas meter valves, but it is not directly addressed in either § 192.145 or in API 6D. As noted above, it is the responsibility of a pipeline operator to justify its use based on compliance with an equivalent standard.
If you have any further questions about the pipeline safety regulations, please contact me at (202) 366-4565.
Sincerely,
Richard D. Huriaux, P.E.
Manager, Regulations
Office of Pipeline Safety