Feature / Application: Stop check valves are essentially the same as Globe valves, except there is no mechanical connection between the stem and the disc. They provide a combination Stop valve and a Piston check valve in one valve. However, they are not designed for throttling. They are used in steam boiler outlet piping when two or more boilers are connected to a common header. Valves must be installed with pressure under the disc, and when the stem is raised, only boiler pressure can raise the disc whenever boiler pressure exceeds header pressure
Valves
Stop Check Valves (SDNR) -Globe type Valve
Advantages: They prevent backflow from the header to boiler