Single Acting vs Double Acting Hydraulic Cylinder: Difference and Usage

When getting to know about Hydraulic cylinder, there are many ways of dividing them into different categories. The easiest method is to count their ports and you can get a “Single Act Hydraulic Cylinder” or “Double Act Hydraulic Cylinder”.

The main difference in function between single and double acting hydraulic cylinder is a double act cylinder push and pull the cylinder rod in both direction using hydraulic pressure, while single act cylinder using hydraulic force in one direction and relies on other force(gravity, spring, air) to pull back.

It is easy to tell that a cylinder is double act or single act by counting its ports. Knowing the basics of hydraulic cylinder is very useful whether you are doing repairing or find a replacement for your own project.

Let get into details of each of cylinders.

 

Single Acting Hydraulic Cylinders

 

A single act hydraulic cylinder has a lot advantages including simplicity, less cost, easier maintenance etc.. It is the simplest way of applying Pascal Law that give you enormous force with little cost.

Because of low cost and high reliability, you can easily find single act hydraulic cylinder in lifting equipment like lift jack, truck lift, dump unloading trailer. It is also used in punch or marking machine, leave a mark with heavy force then pull back by string within cylinder. Due to the cost and structure, through double act cylinders are able to do the same jobs, single act cylinders are the first choice for executing such actions.

 

Double Acting Hydraulic Cylinders

 Compared to single act hydraulic cylinders, double act cylinders are complex in design and cost much in manufacturing. But thanks to the structure, the application ranges of a double act cylinder is widely extended. It need no extra force to recover original status, thus both direction can do the same job, and the speed can be controlled accurately.

Where you can see a double act hydraulic cylinder? It is easy to find double act hydraulic cylinder in engineering machines like garbage trucks, wheels steering system, agricultural machinery etc. Because the nature of double act cylinder, it can be used to execute the most complicated work and generates lot of varieties.

Comparison Table for single acting and double acting

Here is a comparison table refered from Enerpac, showing the difference between single and double act cylinders

 

reference: wikipedia