Z511Z pilot-operated control valves are self-contained, control devices which use energy from the controlled system to operate whereas control valves require external power sources, transmitting instruments and control instruments.

The pilot-operated control valve is designed to work in all general industrial applications. A pressure reducing valve is used for controlling the downstream pressure (p2) to an adjusted set point.

The design of a pressure reducing control valve valve is to close when the downstream pressure rises above a set value.