Double-acting Hydraulic Cylinder

A double-acting hydraulic cylinder has a port at each end, supplied with hydraulic fluid for both the retraction and extension of the piston. A double-acting cylinder is used where an external force is not available to retract the piston or it can be used where high force is required in both directions of travel.A single-acting hydraulic cylinder includes just one port. This is where the hydraulic fluid enters and forces the plunger out in one direction. A double-acting cylinder includes two ports. One for the hydraulic fluid to enter and extend the plunger, and the other for retracting the cylinder.