Properties:

A device designed to be connected to a drainage system to prevent sewer gas from backing up beyond a desired point by forming a water seal in the line. This is accomplished by its peculiar shape, which is usually in the form of the letter p and s. It is provided with an internal shoulder(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 pipes make up close to the shoulders to eliminate pockets and provide a smooth flow of pipe and/or pipe fitting contents. Excludes trap, drain, plumbing fixture; and trap, soil pipe.