On construction sites, hydraulic jacks are primarily used for lifting, supporting, and moving heavy objects. For instance, when assembling large steel beam structures, they can effortlessly lift the beams to the required height with precision. Similarly, when replacing foundation components of a building, they can support a portion of the structure's weight, facilitating safe and efficient operations for workers.

The working principle of a hydraulic jack is based on Pascal's Law. Simply put, in a sealed container filled with liquid, the pressure applied to the liquid can be transmitted equally in all directions. Inside the hydraulic jack, there are two hydraulic cylinders of different diameters. A small force is applied to the smaller cylinder, and the pressure is transmitted through the liquid to the larger cylinder, generating a significant lifting force in the larger cylinder, enabling the effortless lifting of heavy objects.

Operating a hydraulic jack is not complicated. First, ensure the jack is placed on a solid, level surface to prevent tilting during lifting. Then, align the jack's lifting head with the designated lifting point of the heavy object and connect the hydraulic pump. Next, slowly operate the pump handle to allow the fluid to gradually enter the jack, enabling the smooth lifting of the object. When lowering, slowly open the pressure relief valve to let the fluid flow back gradually, allowing the object to descend steadily. Throughout the entire process, closely monitor the state of the heavy object to ensure safety.