Understanding the difference between a single and double acting hydraulic cylinder

The use of hydraulic cylinders, also known as cylinder jacks, extends to a large number of lifting and pushing applications in the load as well as house moving industry. The basic set of a hydraulic cylinder comprises of a hydraulic hose that connects the hydraulic pump to the cylinder. For a jack to operate, setting up of the following 3 components is crucial.

The pump
The hose
The cylinder

The pump takes the hydraulic oil or fluid and transfers it to the connected hydraulic hose. The fluid flows through the hose into the connected hydraulic cylinder. When the oil reaches the cylinder, the piston is raised out of the cylinder.

Hydraulics cylinders are categorized into two classes, single acting cylinders and double acting cylinders.

Single acting cylinders

These types of cylinders transmit the hydraulic force in one direction only. The cylinder may be either pulling or pushing. To return the cylinder to its original position, it is important to apply the force in opposite direction. A built-in spring system can be used to create the opposite effect. The counterforce is generally the load that the cylinder moves.

Single acting cylinders are usually designed as a flask sealed with two chambers in the cylinder, or as plungers equipped with one chamber and no piston seal. When there is only one chamber in the cylinder, the pressure force is exerted on the rod end. These cylinders are usually equipped with one oil connection. In a flask-sealed cylinder, the non-power transmitting chamber can be fitted with air filters or a connection can be formed with the return to the tank. This helps remove excess oil from the cylinder.

The advantages of single-acting cylinders include:

Defined position in case of power failure
Reduced air consumption
Easy actuation via 3/2 – way valve

Double acting cylinders

Double acting cylinders transfer hydraulic power in two different directions, considering that they have both pulling and pushing force. These types of cylinders are designed as a piston which is sealed with two chambers in the cylinder.

The power transfer section of the compressive chamber of the cylinder is within the diameter area of cylinder tube. In double acting cylinders, one oil connection is fitted to the tension side while the other oil connection is fitted to the pressure side.

The advantages of double acting cylinders include:

Force build-up in both directions of movement
Constant force
Strokes of several meters are possible

With a lower capacity cylinder, it is easy to push the extended piston back down and force the fluid to flow back to the pump by just pushing down the piston using your foot. This is when a single acting cylinder is a suitable set-up. On the contrary, with larger capacity cylinders, the piston would not retract fast or with the pressure of your foot. You need to count on either the weight of the load to bring the piston down or have a double acting system to force the piston to retract.

To get the right cylinders, get in touch with one of the leading telescopic cylinders company.