# New Hampshire Public Utilities Commission — Pipeline Safety Interpretation - **operation:** document - **citation:** PI-73-019 - **title:** New Hampshire Public Utilities Commission — Pipeline Safety Interpretation - **source type:** guidance - **agency:** Pipeline and Hazardous Materials Safety Administration - **status:** guidance - **official:** true - **published on:** 1973-07-11 - **effective on:** Not available - **summary:** PI-73-019 response to New Hampshire Public Utilities Commission concerning 192.187. - **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-73-019.json - **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-73-019.md - **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-73-019 - **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1973/PI73019.pdf **body:** <<>> Jul 11 1973 Mr. Bruce B. Ellsworth Gas Safety Engineer New Hampshire Public Utilities Commission 26 Pleasant Street Concord, New Hampshire 03301 Dear Mr. Ellsworth: In your letter of June 25, 1973, you asked about "...§192.187, Vaults: sealing, venting, and ventilation. (a) When the internal volume exceeds 200 cubic feet - (1) The vault or pit must be ventilated with two ducts, each having at least the ventilating diameter of a pipe 4" in diameter;..." The intent of this regulation is to assure that there is adequate ventilation so that a hazardous condition will be avoided. Therefore, if the 8-inch vent with a 4-inch vent inside will provide adequate ventilation to avoid this hazardous condition, the requirements of this regulation will be satisfied. If you have any further questions relative to this requirements, please contact me. Sincerely, Joseph C. Caldwell Director Office of Pipeline Safety dal\192\187\73-07-11 1 - **truncated:** false - **body characters:** 947