Relief valves

These small parts are of great importance in the safe operation of any machine. Relief valves are used to protect other components of the circuit (cylinder pumps, etc.) against pressure surges that result from e.g. sudden stoppages in operation.

Maintaining the appropriate pressure in the hydraulic system consists in the use of a sealing element is maintainded in the closed position by the spring load, available in cartridge type or with a manifold. When the pressure in the circui exceeds the value of the valve setting, the plunger opens and downloads the quantity of oil required to maintain the pressure in the circui at the caibration value. When the pressure int the circui exceeds the valvue of te valve setting, the plunger opens and downloads the quantity of oil required to maintain the pressure in the circuit at the calibration value. The excess pressure (pressure exceeding the valve setting value) and the unused pressure generated return to the tank. Warinng: any pressure on the exhaust line is added at a 1:1 radtio to the calibration pressure.

The pressure maintained by the valve is therefore a function of the calibration valvue and of the flow rate that must be dischargerd. The calibration valuve shold ALWAYS be referred to an univocal value of flow rate and oil viscosity. The calibration value reported in the catalog is meant by flow rate of 5 (+/- 0,5) l/ min , oil temperatur of 50°C and viscosity of 24 mm2/s (cSt).

Available example models:

      VMP 3/8 - 50-250 bar    VMP 1/2 - 50-250 bar     VMP 3/4 - 50-250 bar      VAU 1/2 T: 175; 190bar  VMPP   VMPD  VMPDI  VAU VAU 1/2" OMS   VAU OMP-OMR   VAU 3/4" OMT