• The number and tonnage of jacks are selected according to the weight of the object being lifted and the position where the jacking can be supported. Due to the inconsistent jacking speed of jacks, when several jacks are used at the same time, only 0.5 ~ 0.75 of the allowable load is usually considered.
•  Select jacks according to the weight, shape, environment and construction requirements of the equipment to be jacked.
•  After the hydraulic jack is used up, drain the oil in the oil chamber (the piston falls back to the starting position), wipe the surface clean, and put it in a dry place, with a wooden board or moisture barrier under it, and a special person should keep it.
•  If the jack is parked for a long time, it should be all opened, and the leather bowl, sealing ring, marble, etc. should be cleaned to avoid corrosion.
• The oil used in the jack should be properly kept, and it should not enter dirt and water.

Precautions for Using Jacks

(1) The jack should be placed in a dry and dust-free area, and must not be exposed to direct sunlight or rain.

(2) Before using the jack, it should be wiped clean, and it is necessary to check whether the piston can rise and fall and all components are flexible, whether there is any damage, and whether the oil is clean, etc.

(3) When using a jack, it should be placed on a flat and solid surface. When used on soft ground, a backing plate should be laid to increase the pressure-bearing area. The selection of the base plate should be based on the geological conditions and be adapted to the weight that the jack can bear. A wooden board should be placed at the contact point between the top of the jack and the object to prevent equipment damage and sliding.

(4) The jack must not be used beyond its load capacity. The handle must not be extended at will and multiple people must not apply pressure. The lifting height must not exceed the marked line on the sleeve or piston. If there is no marked line, the lifting height during use must not exceed three quarters of the total height of the screw thread or oil plug.

(5) When operating, the object should be slightly lifted first. Then, check whether the bottom pad of the jack is flat and firm, and whether the jack is vertical. If the jack is uneven, unstable or skewed after being compressed, it should be loosened and properly treated before being lifted upwards.

(6)When lifting, sleepers, wooden boards or iron blocks should be placed under the object as it rises to prevent the risk of the jack returning oil and causing the piston to suddenly drop. When the hydraulic jack is descending, slightly open the throttle to allow it to descend slowly to avoid damaging the sealing rubber bowl or causing oil spraying.

(7) When several jacks are used to lift an object simultaneously, they should be under unified command. They should lift and lower at the same speed simultaneously to prevent the object from tilting during lifting and causing an accident. If conditions permit, a common oil pump can be used for centralized operation.

(8) When releasing a rack-type jack, it should be lowered step by step. Sudden lowering is not allowed; otherwise, the internal device will be damaged by impact, causing the handle to jump and injure people.