# Memo: Internal — Pipeline Safety Interpretation

**Citation:** PI-94-010  
**Type / status:** guidance / guidance  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 1994-02-18

PI-94-010 response to Memo: Internal concerning 192.557.

## Document text

<<<PAGE 1>>>

Information: Interpretations of § 192.557
Cesar De Leon
Director, Technology and Standards Office
Ivan Huntoon
Director, Central Region
This responds to your note of November 7, 1993, which transmitted two old interpretations of
§ 192.557 and asked if they were still correct. The following changes apply:
Letter to John Searcy, dated March 11, 1974
The second sentence of the second paragraph incorrectly implies that the pressure test required in
uprating under § 192.557 must be done concurrently with the uprating process. However, the
source of the pressure test requirement, §192.619(a)(2)(ii), which limits MAOP on the basis of
test pressure, does not prescribe the timing of the test pressure. So any previous test pressure
(including any operating pressure that suffices as a test pressure) could qualify for uprating under
§ 192.557. Only if the pipeline had not previously been pressure tested or if the previous test
pressure were insufficient would the pipeline have to be pressure tested concurrently with
uprating.
In addition, the last sentence of the second paragraph incorrectly implies that the incremental
pressure increases required by §192.557(c) apply to pressure tests done concurrently with
uprating. However, a comparable rule, § 192.555(e), requires incremental pressure increases only
for pipelines that are not tested concurrently with uprating - pipelines that either were previously
pressure tested or need not be pressure tested. Given this comparable rule, it is not reasonable to
interpret § 192.557(c) to require incremental pressure increases during pressure testing.
Letter to William R. Johnson, dated May 6, 1974
As above, the second sentence of the second paragraph incorrectly implies that uprating under
§ 192.557 requires concurrent pressure testing in all cases.
#
dal/192.557/94-02-18

## Provenance

- Official: Yes
- Source: <https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1994/PI94010.pdf>
- Source ID: `phmsa`
- SHA-256: `05a8a8e849e4505fddbcacc775a2cdcc48b26d4f35ea3d42383690a9cfa7059b`
- Retrieved: 2026-08-20T00:59:31.977Z
- Exported: 2026-08-22T03:22:50.282Z
- Document slug: `phmsa-interpretation-pi-94-010`

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