Pressure Sustaining Valves or Back Pressure Regulators

Pressure Sustaining Valves (PSV) sense the upstream pressure and compare it to the setpoint to determine the valve position in order to maintain a set pressure upstream. As the upstream pressure rises the valve starts to open allowing flow downstream and if it falls below the setpoint the valve will shut. The use of these valves enables the prevention of pressure starvation to upstream processes in the event of a major consumption downstream. They can also be used to balance pressures in a ring circuit.