As we all know, hydraulic jacks can not be used horizontally, but why not? Many people do not understand the reason. The following is a brief explanation from guanhang.

The working principle of the hydraulic jack is completed through the internal hydraulic system. It is required to press the hand lever. Under the Pascal principle, the heavy objects are lifted by the liquid pressure. After the operation is completed, the oil return valve is screwed, and the hydraulic oil is squeezed back to the oil tank under the action of heavy pressure and gravity. However, if the hydraulic jack is used horizontally, the flow direction of the liquid in the entire hydraulic system will change. Many people should understand this truth: "water flows to the lower part". Most of the liquid flows from high to low without external force, and the liquid in the hydraulic jack also follows this theorem.

When the hydraulic jack cannot work effectively under the cooperation of gravity, the lifting capacity of the hydraulic jack will also be greatly affected, which is the reason why the hydraulic jack cannot be used horizontally.