Self-locking hydraulic jacks are mainly used for long time to support heavy objects, it can remove the oil pressure can still support heavy objects, and safe and reliable. Can be used for underwater, single acting, load retraction, nut self-locking to make the load more secure, especially in large projects, is easy to operate control and hydraulic jack, designed with safety pressure device, built-in relief valve to prevent overload Jack to facilitate safe operation. The connection of the device is made of high pressure hose and threaded joint connection, with the use of fast, and overcome the rapid traditional joint oil leakage Disadvantages are mainly used for power, construction, machinery manufacturing, mining, railway bridge, shipbuilding and other equipment installation The top of the demolition operations.
1. Application of self-locking type hydraulic jack:
Self-locking type hydraulic jack is used for supporting heavy in the long term, it could support heavy without oil pressure, safe and reliable. It also could be used under water, single acting, return with loading, nut can be locking automatically, making loading more safe, especially in the large project, it is more easily to be operated and controlled, it has pressurizer, pres-relief valve is prevent to over load in the cylinder to protect jack. The connection of the device adopt high pressure and thread couple, it has the function of quick use, and it also could conquer the disadvantage of oil leak. The jack is mainly used for rising, topping, tear downing in electric power, building, machine manufacturing, mining, railway, bridge, shipbuilding and many industrial.
2. Features of self-locking type hydraulic jack:
1) Single acting hydraulic jack.

2) Nut could be locking automatically, making load more safe.

3) Specially-made composite material coating has stronger anti-corrosion, and less force of friction.

4) Overflow hole has the function of limiting stroke.

5) The top of piston rod is with a ring like sphere spacer, it is allow about 8% of bias factor, keeping the pressure of the jack balanced, making jack more longevity.

6) Self-locking hydraulic jack can be customized into double acting hydraulic jack according to the requirement of customer, but closed height need to be increased.
3. Usage of self-locking type hydraulic jack:

1) If the oil capacity is not enough in the pump, it should pour working oil(10#) and then start to work.

2) Estimate tonnage, prohibit to overload.

3) Confirming the center of gravity of jack, finding the point of strength, meanwhile, it should consider the degree of hardness and softness of ground, whether it need to add a plank to prevent jack will be slant when lifting.

4) After jack lift the heavy, it should use some tough wood to support the heavy, prohibit to use jack as upholder to prevent unbalanced load, there has the dangerous of slant.

5) When working, firstly, it should connect quick coupling with jack, choose a suit placement, screw the bolt of oil pump, and then it could start to work, unscrew the bolt, the cylinder will be unloading.