53 Pa. Stat. § 16589
It shall be the duty of the inspector carefully to examine and inspect all stationary steam engines and steam boilers, erected, or in use, at the time this act goes into effect; and thereafter, no stationary steam engine, or steam boilers, shall be erected and put into use and operation, in the city of Philadelphia, without being first inspected and certified to be competent and safe, under the hand and seal of the officer created by this act; and he shall furnish to the owner, proprietor or other person, using such engine, or steam boilers, a certificate, under his hand and the seal of his office, that it has been so inspected, and found to be competent and safe; he shall, from time to time, and as often as he may deem expedient, examine all, or any, such engines, or steam boilers, in use, or operation, and, for such purpose, he, together with his assistants, may enter upon any premises, and require the removal of any part of the building, fixtures, or machinery, and he shall note in a book, to be kept for that purpose, the result of every such examination; and he shall, at least once in every year, make such examination, and give certificate of the result thereof, whenever required.
53 P.S. § 16589