A. 
Gas piping and gas appliances in buildings shall be installed in accordance with standard safe practice.
B. 
Installation of gas piping and appliances for domestic and commercial uses, in accordance with the standards of the National Board of Fire Underwriters for the Installation of Gas Piping and Gas Appliances in Buildings (Pamphlet No. 54), shall be deemed prima facie evidence of installation in accordance with standard safe practice.
A. 
Where the pressure of gas supplied to domestic, commercial or other low-pressure gas piping systems in buildings is in excess of one pound per square inch, an approved gas pressure regulator of sufficient size shall be installed in the service pipe of each such system to prevent pressure in excess of one pound per square inch from being introduced into such building piping.
B. 
If located inside a building, the above required regulator shall be equipped with a vent pipe leading to the outer air. Means shall be employed to prevent water from entering this pipe and also to prevent stoppage of it by insects or foreign matter.
Where gas piping enters a building through a wall or floor of masonry or concrete, any gas pipe or other nearby pipes entering the same wall or floor shall be suitably sealed against the entrance of water or gas.
Approved means for shutting off the flow of gas from outside the building shall be provided on every gas service pipe. Outside gas shutoff cocks or valves shall be located so as to be readily accessible and, when underground, shall be placed in suitable valve boxes, manholes or vaults the covers of which shall be clearly marked "Gas."