The fittings shall not have ledges, shoulders or reductions capable of retarding or obstructing flow in the piping. Threaded drainage pipe fittings shall be of the recessed drainage type. This section shall not apply to tubular waste fittings used to convey vertical flow upstream of the trap seal liquid level of a fixture trap.
(Amend Coun. J. 10-14-21, p. 37722, Art. VII, § 6)