also uses gate and butterfly valves
as the most common shutoff valves, but hydraulic control valves
also play a vital role in regulating pressure and flow. Pressure relief/sustaining hydraulically operated control valve
that can fulfill either of two separate functions: When installing in-line, it sustains minimum pre-set, upstream (back) pressure regardless of fluctuating flow or varying downstream pressure. When installed as a "branched from the line" circulation valve it relieves excessive line pressure when above maximum pre-set. ZhengFeng Control valves
are hydraulically operated, simple and reliable, globe valves with full-bore hydrodynamic body providing an unobstructed flow path and superior performance. The valves balanced rolling-diaphragm assembly is vulcanized with a rugged radial seal disk construction, performing as the valves
only moving part.