The role of hydraulic cylinders can be divided into the following types.
1. Standard double-acting: the power stroke is in two directions and used in most applications;
2. Single-acting cylinder: When thrust is required in only one direction, a single-acting hydraulic cylinder can be used;
3. Double-rod cylinder: When equal displacement is required on both sides of the piston, or when it is mechanically advantageous to connect a load to each end, the additional end of the double-rod cylinder can be used to install cams such as operating limit switches;
4. Spring-return single-acting cylinders: usually limited to small short-stroke cylinders for holding and clamping. The length required to accommodate the return springs makes them limited when they require long strokes;
5. Plunger-type single-acting cylinder: There is only one fluid chamber. This type of hydraulic cylinder is usually installed vertically, and the load reset causes the cylinder to shrink. The plunger-type single-acting cylinder is called a "displacement cylinder", and it is practical for long trips;
6. Multi-stage telescopic cylinder: up to 4 sleeves can be attached, the length of the retractable cylinder is shorter than the standard cylinder, single-acting or double-acting. Multi-stage telescopic cylinders are more expensive than standard cylinders, and are usually used in occasions where the installation space is small but a larger stroke is required;
7. Tandem cylinder: A tandem cylinder is composed of two coaxially installed hydraulic cylinders. The pistons of the two cylinders are linked by a common piston rod. A rod seal is set before the two cylinders so that each cylinder can double-act. When the installation width or height is restricted, the tandem cylinder can increase the output;
8. Double cylinder: A double cylinder is composed of two coaxially installed hydraulic cylinders, the pistons of the two cylinders are not connected. A rod seal is provided between the two cylinders so that each cylinder can double-act. The two cylinders can be installed through the piston rod or back-to-back, usually used to provide three-position work.