# Public Utilities Commission of Ohio — Pipeline Safety Interpretation

- **operation:** document
- **citation:** PI-94-033
- **title:** Public Utilities Commission of Ohio — Pipeline Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 1994-10-18
- **effective on:** Not available
- **summary:** PI-94-033 response to Public Utilities Commission of Ohio concerning 192.619.
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- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-94-033
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1994/PI94033.pdf
**body:**

<<<PAGE 1>>>

October 18, 1994
Mr. Edward M. Steele
Chief, Gas Pipeline Safety Section
The Public Utilities Commission of Ohio
180 E. Broad Street
Columbus, Ohio 43266-0573
Dear Mr. Steele:
I am responding to your letter of May 11, 1994, concerning the maximum allowable operating
pressure (MAOP) of a distribution system. The operator established an MAOP of 5 psig, based
on a maximum safe pressure under § 192.621(a)(5). However, as shown on an MAOP
worksheet, the system was operated at 10 psig on a peak day during 1970. The operator now
alleges the MAOP was mistakenly set at 5 psig and should have been 10 psig. You ask if the
operator may increase the MAOP to 10 psig without uprating under Subpart K of Part 192.
When we addressed this issue in our letter to you dated May 2, 1994, we said the operator must
uprate the system under Subpart K. We still believe that is a correct application of the
regulations. System MAOP is governed by the lowest value determined under § 192.619 and
§ 192.621. The worksheet shows that 5 psig was the lowest value. Thus, 5 psig was
unmistakenly [sic] the correct MAOP, and any increase in MAOP must meet Subpart K.
However, inasmuch as the system has been operated at 10 psig every winter since 1970, the
operator may wish to seek a waiver of Subpart K based on this history of operation.
Sincerely,
Cesar De Leon
Director for Pipeline Safety
Regulatory Programs
dal/192.619
94-10-18
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