Drain valve

摘要

A new and improved drain valve for use with plastic fluid flow components, such as pipes, conduits, fittings, joints and the like is provided. The drain valves include a thermoplastic housing which is directly attached by welding or heat-fusion bonding to a plastic line component or is molded in during the molding step for making the line component. Valving members are assembled to the plastic housing to provide for selective drainage of the plastic line components as desired. The new and improved drain valves permit incorporation of drain valves into plastic conduits and fluid flow systems in a sealed and secure manner substantially in the absence of secondary sealing members.