What Is The Difference Between A Single And Double Acting Cylinder?

There are several sections you can look at within hydraulic cylinders that would allow you to tell them apart. We’re here to help you figure out which is which and get the most out of your components.

Single Acting Cylinder

These hydraulic cylinders have only one port available for the user to connect hydraulic cylinders or hose fittings to. As a result of there being the single port, this is also where the hydraulic fluid enters the system which then extends the rod due to the area difference. To return the piston rod an external force or gravity function is used.

Single acting cylinders are simpler than their double counterparts and require less maintenance throughout their life, due to their actions being determined by the pressure only being on one line.

Advantages:

• Simple design that makes it easy to install.
• Low cost to initially purchase.
• Single port and small housing systems.
• Reduction in valve and piping costs compared to the double acting cylinders.

Disadvantages:

• Compressed fluid requires proper preparation before use.
• Springs take up too much space and limit the available working area.
• Reduced thrust due to the opposing spring’s force.
• With prolonged spring usage, pistons strokes can become inconsistent.

Double Acting Cylinders

Double acting hydraulic cylinders have two separate ports. The first port is where advanced (extending) hydraulic hose fittings will be attached to the cylinder. Whereas the second port is where the retracting hydraulic hose fittings are attached. In this case hydraulic fluid is supplied for both the retraction and extension actions within the hydraulic cylinder, so to return the piston rod an external force is not needed.

With the double acting cylinder the user needs to have full control of the mechanism as the component is moving in two separate directions without the need for manual returns on the piston rod. This means that the hydraulic cylinder needs to be checked regularly and monitored more closely than the single acting cylinder.

Advantages:

• There is more control over movement, as pressurised fluid moves both ways.
• Faster, stronger and uses less energy.
• Offers more design variation with the stroke and bore sizes.
• Many double acting cylinders are ISO compliant as opposed to single pneumatic cylinders.

Disadvantages:

• More costly than a single cylinder.
• Requires a bigger housing - if used as a feed cylinder it needs to be coupled with another machine system.
• In certain situations, fluid consumption may be calculated at different rates.

Unsure which hydraulic cylinder is best for you?
For those needing to eject parts off of a conveyor belt then the single acting cylinder could be for you. Need speed and force? Then the double acting cylinder would be better suited for the application you have in mind.

If you are still unsure about which cylinder is the best one for you, then get in contact with our expert team. They’ll offer technical advice and even find you the perfect hydraulic cylinder for you today!

Or, check out our wide range of hydraulic cylinders to find the hydraulic component you need!