The main overflow valve is an important part of pressure control in hydraulic system of excavator. Its main function is to regulate and limit the system pressure and protect the hydraulic system from damage. The pressure of the hydraulic system is provided by the hydraulic pump. If the consumption of multi section pipeline and the pump pressure are not high, the pressure of hydraulic oil when reaching the working cylinder or motor is very low, which makes it impossible to push the actuator to move. However, if the pressure is too high, the engine speed will drop rapidly, smoke and power will be insufficient, and even the hydraulic oil pipe will burst. However, the excavator shows slow action and weakness mainly due to the low pressure of the main overflow valve.
The failure points of the main overflow valve are usually concentrated on the valve core, spring and spring seat. For example, the valve core is worn, jammed, and the spring is broken. Therefore, when it is detected that the main overflow valve has a fault, only the accessories can be replaced. Another fault is caused by manually adjusting the pressure of the main overflow valve. For example, if the excavator is found weak during operation, someone will increase the pressure value of the main overflow valve because they want to raise the speed. Or lower the pressure value. Both of these conditions may cause the excavator to malfunction.
The main overflow valve is directly related to the power of the excavator. Therefore, if the excavator is weak or the engine speed drops rapidly, check whether the main overflow valve is faulty. In addition, after replacing the main overflow valve, measure the primary pressure value to ensure that the pressure setting is normal. Most importantly, do not easily adjust the pressure setting value, which will adversely affect the performance of the excavator.
