Valves of this type prevent th flow of fluids in a pipe. The name variies between stop valve, shut-off valve or isolating valve. This type of valve has an opening that forms a seat onto which a movable plug (often called disc) can be screwed in to close (or shut) the valve. Typically, automated valves use threaded stems and and are opened and closed by an actuator assembly.

Valves of this type prevent th flow of fluids in a pipe. The name variies between stop valve, shut-off valve or isolating valve. This type of valve has an opening that forms a seat onto which a movable plug (often called disc) can be screwed in to close (or shut) the valve. Typically, automated valves use threaded stems and and are opened and closed by an actuator assembly.

Valve of these series do a shut-off of injection water, which is used for superheated steam temperature control, to downstream valves. Spraywater stop valves have much faster closing times compared to gate valves.