Interpretation Response #PI-01-0116 ([EFI Corporation] [John Jacobus])

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

Interpretation Response Details

Response Publish Date: 09/15/2001

Company Name: EFI Corporation

Individual Name: John Jacobus

Location State: TX 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

September 15, 2001

Mr. John Jacobus
EFI Corporation
2218 Northpark Drive
Kingwood, TX 77339

Dear Mr. Jacobus:

Subsequent to our conversation on September 10, 2001, you forwarded an e-mail asking for an interpretation of the exception to the gas transmission line odorization requirements found in the pipeline safety regulations at 49 CFR §192.625(b)(1). This regulation states that a gas transmission line in a Class 3 or Class 4 location must be odorized unless "[a]t least 50 percent of the length of the line downstream from that location is in a Class 1 or Class 2 location." In your example, you note that ten miles of Class 3 or Class 4 transmission line would not have to be odorized if it terminated with as little as one mile of transmission line in a Class 1 or Class 2 location.

Your interpretation is correct. If 50 percent of more of the transmission line mileage downstream from a Class 3 or Class 4 location is in a Class I or Class 2 location, the gas need not be odorized. This exception to the odorization requirements was included to address long distance pipelines that pass through some Class 3 or Class 4 locations, but are predominately Class 1 or Class 2 downstream from that location.

Although your example is possible, it should be very rare. There are several reasons for this exception. One is that odorization of gas complicates its use as an industrial feed stock. Another is that odorization of transmission lines is of questionable value compared to odorization of distribution pipelines, which operate at a much lower pressure and are more likely to experience slow leaks that could only be detected by odor.

If we can be of further assistance in this matter, please contact me at (202) 366-4565.

Sincerely yours,

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

Regulation Sections