# Arizona Corporation Commission — Pipeline Safety Interpretation

- **operation:** document
- **citation:** PI-93-019
- **title:** Arizona Corporation Commission — Pipeline Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 1993-04-28
- **effective on:** Not available
- **summary:** PI-93-019 response to Arizona Corporation Commission concerning 192.739.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-93-019.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-93-019.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-93-019
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1993/PI93019.pdf
**body:**

<<<PAGE 1>>>

April 28, 1993
Mr. Dan Weaklend
Chief, Pipeline Safety
Arizona Corporation Commission
1200 West Washington
Phoenix, Arizona 85007
Dear Mr. Weaklend:
This letter is to further clarify my letter of October 22, 1992, in which I tried to clarify the specific
inspections and tests the operator should be required to conduct in complying with §192.739. I
explained in that letter that regulator stations must be inspected and tested to comply with
§192.739 using any practicable method that will demonstrate compliance with paragraphs (a)
through (d) of §192.739. Set-point, lock-up, and full-stroke-operation would be part of the
inspection and testing if such tests are practicable at the station concerned.
Regulator stations that use service-type regulators, such as stations that supply master meter
systems, may not be equipped with valving, manifolding, or by-passes. This equipment is needed
to preclude interruption of supply to a customer or group of customers while maintenance is
performed. Consequently, all the inspections and tests that can be done at some regulator stations
may not be practicable at stations with service-type regulators.
In addition, to us, practicable inspections and tests do not require the operator to disassemble the
regulator, re-pipe the regulator, or cut off the supply of gas to the system. Instead, we suggest
that, as a minimum, these service-type regulators be visually inspected, be checked for leaks
(including the regulator vent), and be checked for correct set-point. Verifying the correct set-
point on a service-type regulator can be done by measuring the pressure of the gas (downstream
of the regulator) with a pressure gauge. (We plan to better define "regulator station" in a future
rulemaking).
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<<<PAGE 2>>>

2
I trust that I have further clarified this matter to make it easier to check for compliance with
§192.739. If you have any more concerns, please call James Thomas, Southwest Regional
Director.
Sincerely,
Cesar De Leon
Director, Regulatory Programs
Office of Pipeline Safety
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