In order to understand the precautions of the pressure reducing valve in use, first of all, select a pressure reducing valve suitable for the hydraulic system:
1. Select the type of pressure reducing valve according to the operating conditions and specific requirements of the hydraulic system;
2. According to the working pressure and flow rate of the hydraulic system, the rated pressure and flow rate (path) specifications of the pressure reducing valve are selected properly;
3. According to the purpose and role of the pressure reducing valve in the hydraulic system to determine and adjust the secondary pressure, attention must be paid to the relationship between the set pressure of the relief valve and the load pressure of the actuator.
In the use of the process should be noted as follows:
1, the correct use of pressure relief valve connection method, the correct selection of connectors (installed base plate or pipe joints), and pay attention to the sealing joints;
2. Each port of the valve should be properly connected to the system, and the external port must be directly connected to the tank;
3. Note that the changing trend of the opening and closing characteristics of the pressure reducing valve is opposite to that of the relief valve (ie, the secondary pressure is reduced when the flow rate of the pressure reducing valve increases);
4. The secondary pressure setting value of the main pressure reducing valve should be higher than the setting pressure of the remote pressure regulating valve;
5. The adjustment range of secondary pressure is determined by the flow rate of the pressure regulating spring and valve used;
6, the minimum regulating pressure should ensure that the difference between primary and secondary pressure is 0.3-lMPa.
7, should pay attention to the pressure relief valve more than other control valves, there is always out of the pilot valve oil (sometimes up to 1L/min above), thus affecting the choice of hydraulic pump capacity;
8, adjust the pressure should pay attention to the correct direction of rotation to adjust the pressure regulating mechanism, pressure adjustment should be fixed at the end of the lock nut;
9. If a multi-stage decompression control is required for the system through the remote control port of the pilot-operated pressure reducing valve, the screw plug of the remote control port shall be unscrewed and connected to the control oil circuit; otherwise, the remote control shall be tightly sealed;
10. The oil return port of the unloading relief valve should be directly connected to the tank to reduce back pressure.
11. When the pressure reducing valve is faulty or the noise is large, etc., the following methods may be used for diagnosis and troubleshooting. The parts of the valve that have been disassembled and washed shall be properly installed and the secondary pollution shall be prevented.
Pressure relief valve common faults and troubleshooting
Common malfunctions:
1, can not decompression or no secondary pressure;
2, the secondary pressure can not continue to rise or pressure instability;
3, the pressure during the pressure adjustment process is not continuous, but uneven decline.
cause of issue:
1. The drain outlet is different or the drain passage is blocked, so that the main valve plug is blocked in the original position and cannot be closed;
2, the pilot valve is blocked;
3, the pilot valve is not strict, the main valve block in a certain position, the load has mechanical interference;
4. One-way valve in one-way pressure reducing valve leaks too much;
5, pressure spring bending or breaking;
Discharge method:
1. Check the drain line, drain port, pilot valve, main spool, one-way valve, etc. and repair it;
2, check the discharge actuator mechanical interference;
3, demolition and replacement.