Pressure Sustaining Valves

A pressure sustaining valve regulates the flow rate of a process flow based on the operating pressure on the inlet side. The process flow is passed through if the operating pressure is above a manually set value. If the operating pressure is below this value, the process flow will be interrupted. For operation, a pressure difference across the pressure sustaining valve is required. The flow rate does ideally not affect this pressure difference, provided that it does not exceed the performance limits of the device. In practical applications however, with the same settings applied, the pressure difference is usually slightly higher at higher flow rates compared to lower ones.

Pressure sustaining valves can be seen as valves that act entirely mechanically, without an electronic control and without a drive powered by an external force. They can be an economical alternative to control valves, if neither a connection to the process control system is required nor an automated constant interruption of the process flow.

Usage in the sense of a safety valve is not permitted for pressure sustaining valves.