4 in. (101.6 mm) NPT-Threaded Check Valve provides a watertight defense against pollution caused by backflow from water-based systems, including sprinkler and standpipe systems. This UL-listed valve can be installed on a supply line, fire department connection (FDC), fire pump discharge, or gravity tank connection in accordance with NFPA code and local fire code.
This Threaded Check Valve has a 4 in. (101.6 mm) male NPT (MNPT) inlet and a 4 in. (101.6 mm) female NPT (FNPT) outlet. This in-line valve operates automatically when pressure drops or flows revers and features an o-ring seat and a spring-loaded clapper.