This Standard covers plumbing waste fittings of sizes NPS-2 and smaller.

This Standard does not cover
(a) plumbing supply fittings, which are covered by ASME A112.18.1/CSA B125.1;
(b) other devices (e.g., temperature-actuated in-line mixing valves), which are covered by CSA B125.3 or other plumbing product standards; and
(c) flexible water connectors under continuous pressure, which are covered by ASME A112.18.6/CSA B125.6.

This Standard does not cover pipes and tubes or pipe and tube fittings that are downstream of the trap.

A112.18.2 is to be used in conjunction with components described in other volumes of the ASME A112 series. Careful application of these A112 standards will help users to comply with pertinent regulations—including those derived from the Uniform Plumbing Code (UPC) and the International Plumbing Code (IPC) —while achieving the operational and safety benefits to be gained from the many industry best-practices detailed within these volumes.

Intended for manufacturers of plumbing materials and equipment to enhance water conservation and comply with jurisdictional regulation, plus governmental and other regulatory bodies.