How does a ROBOT control valve work

Pressure relief valve

Overload protection through pressure relief valves

For safety reasons and component protection, it is necessary for almost every hydraulic system to limit the pressure in the system. Directly controlled pressure relief valves are sufficient for small flow rates.

Image: Principle and circuit symbol of a direct operated pressure relief valve

The closer element is controlled by a spring according to its strength and preload (mostly adjustable) pressed onto the seat. If the compressive force of the oil exceeds the spring force - which means an increase in pressure, opens the cone the connection. The ones in the system excess Liquid flows back into the tank via the pressure relief valve.

The circuit diagram below shows how the pressure relief valve is connected as a safety valve:

  • It is not connected in the main stream, but in the secondary stream.
  • The starting position is closed
  • It is controlled from the input side