1. Oil leakage from the piston seal in the oil cylinder: Since the oil leakage of the oil seal in the oil cylinder cannot be seen from the outside, it is difficult and complicated to judge whether the sealing ring in the oil cylinder is worn or damaged. If the hydraulic oil keeps flowing out from the oil return pipe joint on the oil cylinder, since the piston has moved forward at this time, it can be judged The piston seal is damaged and should be replaced. In this case, the replacement is more complicated. Please repair it under the guidance of the manufacturer's personnel to avoid danger.

2. Electromagnetic reversing valve failure: The inlet and outlet pipes can be disassembled from the oil cylinder and the electromagnetic reversing valve can be pressed and loosened to check the internal leakage. If the internal leakage is too large, use kerosene to clean or replace the sealing parts. Small internal leakage is not enough to affect the oil pressure, but it will slow down the advance and retreat speed of the oil cylinder. The push rod of the reversing valve is shortened due to long-term impact, wear and tear, or the contact point between the armature and the push rod is worn, resulting in insufficient reversing stroke of the spool. .

3. Insufficient oil level: Because the hydraulic system of the automatic pressure-maintaining automatic filter press is in a high pressure state for a long time, some seals will inevitably seep oil. At the same time, after the automatic filter press is used for a period of time, a small amount of hydraulic oil will also evaporate naturally. These all cause the oil level of the fuel tank to drop. When the oil level is too low, the oil pump will not be able to pump the 46th or 68th hydraulic oil.

4. Failure of overflow valve Failure of insufficient oil pressure in hydraulic system: more than 50% is caused by failure of overflow valve. If the pressure of the overflow valve is adjusted to a large value and still cannot meet the pressure requirements of the automatic filter press, the overflow valve should be considered Whether there is a fault. The effective way to judge the failure of the relief valve is the replacement method, replace it with a relief valve of the same type and try it out. If the pressure after the replacement can meet the requirements, it can basically be judged as a failure of the relief valve.