Pressure Relief valve

The relief valve (RV) is a type of valve used to control or limit the pressure in a system or vessel which can build up for a process upset, instrument or equipment failure, or fire. The pressure is relieved by allowing the pressurised fluid to flow from an auxiliary passage out of the system.

Has the task to limit the pressure in a hydraulic system or in a part of the system.

The pressure can rise in a hydraulic system if:

  • The flow rate from the pump is larger than the flow rate through the actuator
  • The volume of a closed system is reduced
  • The load of the actuator rises
  • Heat is introduced into a closed system
  • The hydraulic resistance of the system rises