What is a double acting cylinder?

A double acting cylinder is characterized by its ability to exert force in both directions. This design allows the cylinder to extend and retract, applying force on the rod during both the forward and backward strokes. This dual action is made possible through the use of ports on both ends of the cylinder, which enable hydraulic fluid to be directed to either side of the piston. This characteristic is essential for applications requiring controlled motion both when moving outwards and when retracting, making double acting cylinders highly efficient and versatile in various mechanical systems.

In contrast, a cylinder that only exerts force in one direction (like a single acting cylinder) can only perform motion on one stroke, relying on an external force to return to its starting position. A cylinder that does not exert any force would not be functional or useful in any hydraulic application. Additionally, saying it's used only for lifting describes functionality too narrowly; double acting cylinders can be found in numerous applications, including pushing, pulling, and various forms of actuation across different industries.