Hydraulic Pressure Control Valve

Pressure shut-off valves and pressure sequence valves are hydraulic valves with a fixed throttle whereas relief and reducing valves are hydraulic valves with a variable throttle.
The most common types of pressure control valves are the pressure relief valve and the pressure reducing valve. open or closed) occurs either gradually (by control) or suddenly (by switch). A change in position of the pressure control valve (i.e. Pressure reducing valves reduce the pressure supplied to a sub-system of a hydraulic system. The switching pressure is generally a variable setting on the valve itself. Every pressure control valve switches (or controls) at a predetermined pressure setting. Pressure relief valves control the system pressure by relieving part, or all, of the flow to tank.