Gas piping and fixtures in all new buildings and all alterations and extensions made to the gas piping in old buildings must be done in accordance with the following rules.
All gas pipe shall be of the best quality wrought iron or steel and of the kind classed as standard pipe and as hereinbefore called for. No gas pipe shall be smaller than 3/8 inch.
All fittings (except stopcocks or valves) shall be of galvanized malleable iron.
Outlets for gas ranges shall have a diameter not less than required for six burners, and all gas heaters shall have a straightway cock on service pipe.