Pressure Relief Valve

Pressure relief valves are used in hydraulic systems to limit the pressure at single or multiple sites within the hydraulic circuit. The pressure relief valve diverts the pressurized flow to the reservoir to limit the pressure in the entire system. They are also referred to as pressure safety valves as they act as a protection to stop the pressure from rising too high in the case of any circuit component failure.

All hydraulic systems must have a pressure relief valve installed for safety purposes. They are usually installed directly under the pump, which allows them to control the system pressure. These valves can also be used to protect isolated components as they can be used in different parts of the hydraulic circuit.

Pressure relief valves are often used as over-pressure protection devices as they generate heat upon controlling the pressures of load and the system. They are generally seen being used within pilot pressure control systems and test rigs.

Some of the main functions of pressure relief valves are as follows:

1. Relief from pressure or shock surges
2. Protection from hydraulic system component failure
3. Deceleration load protection
4. Protection in the condition of overload
5. Limiting of system pressure
6. Maintenance of back-pressure
7. Pilot pressure maintenance in 2-staged valves
8. Electrical switching of unloading valves