Case 1: The quality of the seal is not good. The seal structure is unreasonable, the material is not good, the manufacturing process and accuracy are poor, the mold is defective, and the trimming defect causes the hydraulic jack to be damaged.

Case 2. Reasons for storage, transportation and maintenance. Storage overflow, improper humidity, corrosion by oxygen and ozone, improper stacking conditions, and improper maintenance cause damage to the hydraulic jack. Case 3. Parts manufacturing and assembly are of poor quality.

Case 3: The processing accuracy and surface roughness of the accessories do not meet the requirements, and the processing method is unreasonable.When the seal passes through the sharp edge and the thread tip during installation, the lip is damaged due to unprotected and the hydraulic jack is damaged.

Case 4: The fitting design structure is unreasonable. The selected seals cannot meet the requirements of working pressure, speed and temperature, and are not compatible with the oil medium and environmental conditions. The grooves for installing the seals are not designed properly, and the gap and compression are selected. Unreasonable, and failure to pay attention to anti-corrosion, anti-vibration, pressure equalization, etc., are all unreasonable design structures of the mating parts, which cause damage to the hydraulic jack during use.