Openings through sidewalks for the delivery of fuel, when lawfully in existence, shall be not greater than thirty inches in diameter, shall be circular in form and shall be effectually closed when not in actual use by an iron cover set flush within the surface of the sidewalk, level with the sidewalk and securely locked in place. All openings in the sidewalk for the admission of light and air shall be closed and protected either by substantial iron gratings or illuminating pavement of such a design and so placed as to be satisfactory to the City Engineer.
(1974 Code § 4.7)