Drainage Pipe Coupling

A straight fitting having an internally threaded or unthreaded connection of the same size on both ends. It is provided with internal shoulde (s) at the end(s) of its internal threaded or unthreaded portion, whose inside diameter conforms to standard weight wrought iron pipe or copper drainage, waste and vent (dwv) tube. When connected, the mating pipe and/or pipe fitting is close to the shoulder to eliminate a pocket and provide a smooth flow to the contents of the line. It is designed to join a pipe or pipe fitting to another pipe or pipe fitting in a drainage line. Excludes coupling, pipe.