Abstract: A fluid pressure operated valve device for connection to the inlet and outlet sides of a pilot valve has a two part, axially separable hollow cylindrical body with axially aligned inlet and outlet passageways, a side ported hollow cylindrical liner of smaller diameter having a closed end and an open end is fixed in the body with its open end surrounding the inlet passageway, a biased closed valve element reciprocates in the liner and controls the ports, passageway means for applying inlet pressure to the interior of the liner to close the valve element, and passageway means leading from the interior of the liner to the exterior of the valve body and from the exterior of the valve body through the valve body to the outlet passageway.

Abstract: A main hydraulically operated valve body has a valve element therein which is biased closed when inlet pressure is applied to both sides thereof and is moved openward when inlet pressure is variably exhausted from its outlet side through a pilot valve having a body rigidly mounted on a casing enclosing a meter actuated preset mechanism. The pilot valve body has a single valve element therein connected to the preset mechanism for preventing and controlling exhaustion of inlet pressure therethrough and conduit connects the main and pilot valve bodies.