All galvanized genuine wrought iron pipe shall be lap-welded; fittings shall be the special extra heavy cast iron recessed and threaded drainage fittings with smooth interior waterway and threads tapped so as to give a uniform grade to branches of not less than one-fourth inch per foot; joints shall be screwed joints, made up with red lead and the burr formed in cutting shall be carefully reamed out; short nipples, where the unthreaded part of the pipe is less than one and one-half inches long shall be of the thickness and weight known as extra heavy.
(1967 Code, § 16-13) Penalty, see § 10.99