53 Pa. Stat. § 4643
The closet and all other fixtures, except sinks, must be set open, and free from all enclosing woodwork. In tenement-houses and lodging-houses, sinks must be entirely open, set on iron legs or brackets, without any enclosing woodwork. Iron enameled waterproof cabinets are permissible under all lavoratories, and under sinks in tenement-houses and lodging-houses.
Any fixture removed from service, either to be discarded or replaced with new by any owner, must have the inspected approval of the inspection department of plumbing under whose jurisdiction it is/was at time of removal before it can be reinstalled. If, after inspection, it is found to conform with proper standard, so as not to create a potential hazard to public or private health, it may be labeled, numbered, and certificate issued for its reinstallation with no other limitations reserved. No used plumbing fixture, intended for sanitary purposes, or any that may be connected to the domestic water system of any dwelling or building, can be installed without the inspection, approval of the department of plumbing, or board or bureau of health.
53 P.S. § 4643