# Tennessee Public Service Commission\< — Pipeline Safety Interpretation

**Citation:** PI-75-029  
**Type / status:** guidance / guidance  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 1975-06-09

PI-75-029 response to Tennessee Public Service Commission< concerning 192.63.

## Document text

<<<PAGE 1>>>

Jun 9 1975
Mr. John Searcy, Director
Engineering Division
Tennessee Public Service
Commission
Cordell Hull Building
Nashville, Tennessee 37219
Dear Mr. Searcy:
This responds to your letter of March 19, 1975, which references a proposed marking procedure
for use in compliance with 49 CFR 192.63. You ask whether pipeline components marked as
outlined in the proposed procedure would meet the marking requirements of Section 192.63, or
what changes in the procedure, if any, will be necessary to effect compliance.
Section 192.63 requires that, except for certain items manufactured before November 12, 1970,
each component used in a pipeline to which that Section applies must be marked as prescribed in
the specification or standard to which it was manufactured or MSS Standard Practice, SP-25.
We note that the proposed procedure primarily relates to color coding. This method of marking
does not comply with Section 192.63 because it does not meet the requirements of applicable
specifications or standards to which components are manufactured or MSS Standard Practice SP-
25. The procedure should be revised in accordance with applicable marking requirements to
effect compliance with Section 192.63. Of course, in addition to the required markings, an
operator may voluntarily use color coding to mark components for any purpose other than
compliance with Section 192.63.
We are also concerned that the proposed procedure would permit the use of unmarked pipe and
nipples and other unmarked fittings. Components which are not marked in accordance with
Section 192.63 may not be used in a pipeline to which that Section applies.
Your further ask whether fittings, the manufacturer of which cannot be identified, may be used in
any portion of a gas system subject to Section 192.63.
Fittings whose manufacturer cannot be identified may not be used in a pipeline to which Section
192.63 applies because the name of the manufacturer is part of the required marking.
Identification
dal\192.1-b\63\75-06-09
1

<<<PAGE 2>>>

of the manufacturer is also essential to application of the exception from marking under Section
192.63(d).
Thank you for your continued efforts in pipeline safety.
Sincerely,
Joseph C. Caldwell
Director
Office of Pipeline Safety
dal\192.1-b\63\75-06-09
2

## Provenance

- Official: Yes
- Source: <https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1975/PI75029.pdf>
- Source ID: `phmsa`
- SHA-256: `dc6d7c2cfc82d1897ea5ce962b78490bd6e5fc98c0917d777382a60789f7979c`
- Retrieved: 2026-08-20T00:59:31.977Z
- Exported: 2026-08-22T04:25:47.271Z
- Document slug: `phmsa-interpretation-pi-75-029`

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