pressure and the load relief pressure difference is an important performance index of unloading relief valve, generally loading pressure relief pressure of about 85 percentage. The same as the relief valve performance.
1. Unloading valve works
unloading relief valve of the relief valve and the check valve. When the system pressure reaches the opening pressure of the relief valve, relief valve opens, pump unloading; when the system pressure was reduced closing pressure relief valve, the relief valve closed, the pump to the system load. The pressure at the pump discharge pressure is called unloading, loading state of the pump is called load pressure.
2. Unloading valve function of the application
The main function of unloading relief valve of the pump is controlled automatically loading or unloading. Given the function of unloading relief valve, there are some differences between the required discharge pressure and the load pressure bearing. The difference is too small, the pump unloading and loading action too often; the difference is too large, the system changed so much pressure. .
The main purpose unload valve 3
A pump energy storage system in an automatic loading and unloading;..
B high and low pressure pump assembly high flow low pressure pump unloading .
4. Unloading valve selection
unloading relief valve for a hydraulic circuit with accumulator, when charging the accumulatorAutomatically unloading the hydraulic pump when the hydraulic pressure reaches the set pressure of the valve. Valves have built a check valve to prevent a pressure oil in the accumulator back. At this time, the system is maintained by the accumulator and the fuel supply pump thus received energy-saving effect unloading. When the accumulator oil pressure dropped to about 85 percentage of the set pressure of the valve, the valve is once set, the hydraulic pump to the accumulator filling recovery.
Such a valve can also be used to double-pump high-pressure circuit. Two low pressure pump supplies oil to the system at the same time, this high pressure pump unloading valve so that the large and the high pressure portion spaced from it.
for the valve between the accumulator and the accumulator 10 to the pressure drop must not exceed the percentage of the set pressure. Leakage drain port back pressure valve can not exceed the percentage of the set pressure of 2