Single Acting Hydraulic Jack

Ⅰ. Single acting jacks use one oil port(circuit) for inlet and outlet, and both lifting and retraction are performed through the same oil hole.

Ⅱ. The principle of single acting jack lifting is that the hydraulic oil pump (electric or manual) supplies oil to the hydraulic jack through a high-pressure oil pipe.

Ⅲ. Single acting jacks use oil pressure lifting springs to achieve automatic reset of single acting hydraulic jacks, or return by applying a stable external force.

Ⅳ. The structure is relatively simple and there may be fewer failure points. If operated properly, it is safer and more reliable in some specific small-scale lifting operations.

Double Acting Hydraulic Jack

Ⅰ. Double acting jacks use dual oil circuits, separate oil supply and oil return, and oil is supplied through the oil supply hole and oil return hole during lifting and retraction.

Ⅱ. The lifting principle of the double acting jack is the process of the hydraulic pump station (electric or manual oil pump) supplying oil to the double acting hydraulic jack through the high-pressure oil pipe;

Ⅲ. The double-acting hydraulic jack realizes the lifting and resetting of the jack by oil pressure lifting and oil pressure retraction.

Ⅳ. Because the lifting and retraction can be actively controlled, it is more stable and controllable during operation, especially in some occasions where the height and operation process need to be precisely controlled, the safety is relatively high.

In general, choose the appropriate jack according to the specific use scenario, and operate it strictly in accordance with the operating procedures, and perform regular maintenance and inspection to ensure safe use.

Applicable Scenarios of Single Acting Jacks and Double Acting Jacks

Applicable Situations for Single Acting Jacks

Ⅰ. Occasions where the lifting height requirement is not high and the working space is relatively narrow. For example, when performing local lifting and maintenance at the bottom of some small equipment, the single acting jack has a simple structure, a small size, and is easier to place and operate when the space is limited.

Ⅱ. Operations that do not require high return speed. If you only need to lift the heavy object and can accept a slower return speed, you can choose a single acting jack, which relies on external forces such as gravity or springs to return, and does not require a complex hydraulic circuit to control the return action.

Applicable Situations for Double Acting Jacks

Ⅰ. Occasions where both the lifting and lowering processes need to be precisely controlled. For example, in the installation and commissioning of large mechanical equipment, the height needs to be adjusted frequently and the accuracy is high. The double acting jack can actively control the retraction action to achieve more accurate height adjustment.

Ⅱ. Situations where there is a need for frequent lifting and retraction operations. For example, in some continuous production lines, multiple lifting and lowering operations need to be performed quickly and efficiently. Double acting jacks can meet the requirements of such frequent operations.

It is not necessary to use a double acting jack if the cargo is heavy. If you only lift the heavy object to a certain height at one time and can accept a slower return method, even if the cargo is heavy, a single acting jack can be used within its rated load range. 

However, if the heavy object needs to be adjusted frequently and the operation accuracy and speed are required, then a double acting jack is more suitable.