Automatic unloading valves are mainly used in hydraulic circuits equipped with accumulators, which automatically unload the hydraulic pump when the accumulator charging pressure reaches the set pressure of the valve. There is a built-in one-way valve in the valve to prevent the backflow of pressurized oil in the accumulator. At this time, the accumulator maintains the supply of oil to the system while the pump unloads, thereby achieving energy-saving effects. When the oil pressure in the accumulator drops to about 85% of the set pressure of the valve, the valve reloads and the hydraulic pump resumes charging the accumulator.

Working principle of automatic unloading valve: The automatic opening and closing of the valve is controlled by the pressure area difference between the upper and lower chambers, which is adjusted by a compression spring. The valve is divided into two parts, upper and lower, with small holes connected. When the fan is not started, the valve is open. If the fan is started, the air is blown into the valve body and unloaded. As the pressure increases, the diaphragm compresses the spring downward to close the sealing head. It adopts a pressure self tightening sealing structure, and the higher the medium pressure, the better the sealing performance. The design of valve split structure and the use of internal rubber parts greatly improve assembly accuracy, with functions such as lightweight valve body, low noise, smooth operation, long service life, easy installation, maintenance and disassembly, and automatic adjustment and control.

Common problems and solutions of automatic unloading valves:

1. Valve overheating issue: In high-pressure or high-temperature environments, overheating may occur due to the following reasons:

Check if the valve is selected correctly and meets the working pressure and temperature requirements of the system.

Check if the valve has sufficient cooling space to ensure that the surrounding environment temperature is appropriate.

Check if the valve has sufficient lubrication to ensure smooth valve movement.

2. Unstable pressure problem: It plays a role in stabilizing pressure in the system. If the pressure is unstable, it may be due to the following reasons:

Check if the valve adjustment range is correct and adjust according to system requirements.

Check if the valve spring is loose or damaged, and replace the spring if necessary,

Check whether the valve is dirty or blocked, and clean the inside of the valve.

3. Leakage issue: If there is a leakage issue, it may cause the system to be unable to maintain the required pressure. The solutions include:

Check if the valve sealing surface is damaged or dirty, clean or replace the sealing surface,

Check if the valve seat ring is worn or aged, and replace the seat if necessary,

Check if the valve is installed and adjusted correctly to ensure good sealing,

4. Noise issue: Noise may be generated during operation, possibly due to the following reasons:

Check if the valve is installed correctly and ensure a stable connection between the valve and the pipeline.

Check for loose parts in the valve and tighten if necessary.

Check the valve for damaged components and replace them if necessary.

5. Valve cannot be opened or closed: There may be situations where the valve cannot be opened or closed, which may be due to the following reasons:

Check for foreign objects or dirt inside the valve and clean the inside of the valve.

Check if the valve spring is damaged or stuck, and replace the spring if necessary.

Check if the valve piston or spool is stuck and ensure it moves freely.