Interpretation Response #PI-73-007
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Mr. Jerry Rich
Director, Bureau of Investigations, Service and Enforcement
Pennsylvania Public Utility Commission
P. O. Box 3265
Harrisburg, Pennsylvania 17120
Dear Mr. Rich:
This is in reference to your letter dated January 17, 1973, concerning a possible violation of Section 192.199(g), 49 CFR, by the Equitable Gas Company in its regulator station R. B.-26. The intent of Section 192.199(g) is to require gas operators to install pressure relief or pressure limiting devices in a manner to prevent any single incident such as an explosion in a vault or damage by a vehicle from affecting the operation of both the overpressure protective device and the district regulator. Therefore, the overpressure protective device and the district regulator must be sufficiently separated or adequately isolated from each other to prevent a single incident such as an explosion or damage by a vehicle from affecting the operation of both. Your letter indicates that the Commission believes that compliance with Section 192.199(g) was achieved by rebuilding the regulator station according to the proposed plan in Figure 3 in the National Transportation Safety Board Report Number NTSB-PAR-72-2. From the information contained in the report, the regulator and the overpressure protection device were to be less than 3 feet apart in the same vault.
It appears that a single incident such as an explosion in the vault would affect the operation of both; therefore, the proposed revamping of regulator station R.B.-26 as shown in Figure 3 of the NTSB report would not be in compliance with Section 192.199(g).
Based on the intent of Section 192.199(g), as stated above, would you please advise whether you believe Equitable Gas Company to be in compliance with Section 192.199(g); and, if so, in what manner the Company has achieved compliance with this regulation.
Your immediate attention to this matter will be greatly appreciated.
Joseph C. Caldwell
Office of Pipeline Safety
|Requirements for design of pressure relief and limiting devices