53 Pa. Stat. § 14793
Plumbers before commencing the construction of plumbing work in any building in the said cities (except in case of repairs, which are here defined to relate to the mending of leaks in soil-, vent-, or waste-pipes, faucets, valves, and water-supply pipes, and shall not be construed to admit of the replacing of any fixture, such as water-closet, bath-tubs, wash-stands, sinks, et cetera, or the respective traps for such fixtures), shall submit to the Board or Bureau of Health plans and specifications, legibly drawn in ink, on blanks to be furnished by said board or bureau. Where two or more buildings are located together and on the same street, and the plumbing work is identical in each, one plan will be sufficient. Plans will be approved or rejected within twenty-four hours after their receipt.
53 P.S. § 14793