Jack refers to the light and small lifting equipment that uses rigid lifting parts as working devices and lifts heavy objects in a small stroke through the top bracket or the bottom bracket. Jacks are mainly used in factories, mines, transportation and other departments as vehicle repair and other lifting and supporting work. Its structure is light and firm, flexible and reliable, and it can be carried and operated by one person.

　　Matters needing attention:

　　Jack is a safe and reliable lifting equipment, and there will be no problems in general. However, there are also the following precautions in use:

　　(1) The working medium of general jacks is YB-N32 hydraulic oil. When the ambient temperature is lower than 10℃, YB-N22 hydraulic oil can be used, and when the ambient temperature is higher than 40℃, YB-N46 hydraulic oil can be used.

　　(2) During work, the liquid level of the oil tank should always be kept at the center line of the oil gauge to prevent the oil pump from sucking air. When refueling, a 120-mesh oil screen should be used to filter out the impurities in the new oil. When frequently used, the oil filter should be cleaned every two months, the oil tank should be cleaned every six months, and the new oil should be replaced at the same time.

　　(3) The normal working temperature of the jack oil pump is 10 ~ 50℃. If the oil temperature is too high, it is necessary to take cooling measures or stop the pump; If the oil temperature is too low, heating measures or low-pressure operation should be taken to increase the oil temperature.

　　(4) Before starting the motor, change the reversing valve to the middle half position, inching it several times to prevent the high-pressure pump from sucking air and removing air before using it.

　　(5) The working pressure set by the pump when it leaves the factory shall not be increased arbitrarily.

　　(6) When the high-pressure hose leaves the factory, it has undergone a pressure test which is 1.25 times of the rated pressure. Due to the aging of the gum, users should pay attention to regular inspection and check it once every six months. In case of leakage, bulge or explosion during the pressure test, it must be replaced. When in use, discount and sharp bend should be avoided, and at the same time, it should not be too close to the hose to prevent people from being hurt by blasting. In fixed situations, steel pipes can be used instead.

　　(7) The pump shall be overhauled once a year. All parts shall be cleaned with kerosene, and the mating surfaces of jacks shall be protected from any bump. After assembly, all moving parts shall move flexibly without local jam.