Excavator hydraulic parts PC200-6 PC120-6 relief valve 708-2L-04523

Relief valve common troubleshooting methods
The common faults of the relief valve are: vibration and noise; The adjustment pressure is low, the adjustment is ineffective; The adjustment pressure is high, the adjustment is ineffective; Pressure fluctuation; Leaks, etc. The causes of these failures and troubleshooting methods are as follows:

1. Vibration and noise

1) Fluid noise should be taken according to the following reasons:

(1) Cavitation cavitation noise and eddy current and shear fluid noise after the overflow valve should be replaced;

(2) The impact sound of the pressure wave during the unloading of the relief valve should increase the unloading time, and the high-frequency noise caused by the uneven distribution of pressure in the pilot valve and the main slide valve should improve the geometric accuracy of the valve, increase the diameter of the return oil pipe, choose a softer main valve spring and the appropriate viscosity of the oil return pipe with air, should check the seal and exhaust. If the back pressure in the return oil pipe is too large, the return oil pipe diameter should be increased and the return oil pipe should be set separately.

(3) The relief valve internal pressure control area into the air, should check the seal and exhaust flow exceeds the allowable value, should be selected to match the flow of the relief valve.

2) Mechanical noise, corresponding measures should be taken according to the following reasons:

The slide valve and the valve hole are too tight or too loose to cause vibration and noise, should check and repair the pressure regulating spring is too soft or deformed to produce noise, should replace the pressure regulating spring

If the pressure regulating nut is loose, it should be tightened and the taper valve should be worn out, it should be repaired in time to generate resonance noise with other components of the system, and it should be dealt with in time to eliminate resonance.