Single-acting cylinders vs double-acting cylinders

Here at API Pneumatic UK, we deal with a range of cylinder enquiries daily. The majority come from customers who know precisely what cylinder type they want and how it will complement their systems, while others are completely new to the world of pneumatics. As such, they may not know which cylinder type is best for their application requirements. If you are a first-time cylinder buyer, you might find that you fall into this category.

As such, it is important to understand that the two most common working principles for cylinder types are single-acting and double-acting. Before you can understand what cylinder type is best for you, you must first understand the difference between single-acting cylinders and double-acting cylinders. Here, API UK breaks down each of their advantages, as well as which industries and applications are best suited to each of these cylinder types in this helpful guide for first-time cylinder buyers.

What are single-acting cylinders?

The working principle of single-acting cylinders is to transfer hydraulic fluids or an output force in one direction only. The piston rod housed within the cylinder can push outwards but cannot pull back, which is why single-acting cylinders require a force in the opposite direction to return the rod back to its original position.

This is traditionally achieved by a second component, such as a pump, motor or internal springs. The two main types of single-acting cylinders are push types and pull types, whereby applications of pressure produce push or pull motions in a singular direction.

Advantages of single-acting cylinders

  • Reliability
  • Simplicity
  • Compact
  • Economical

What applications are best suited for single-acting cylinders

  • Clamping
  • Positioning
  • Punching
  • Reciprocating engines
  • Pumps
  • Hydraulic rams

What are double-acting cylinders?

Double-acting cylinders are the polar opposite of their single-acting counterparts, as their working principle is to transfer hydraulic fluids and output force in both extending and retracting directions. Ports at each end of the cylinder allow the piston to move forwards and backwards. This is achieved by alternating which port receives the pressure. In operation, the pressure is applied alternately to the ends of the piston.

This application produces thrust in the positive and negative stroke to perform push and pull functions. This means outward and retraction movements can be achieved under the cylinder’s own pressure without any external sources of power. Whereas single-acting cylinders only have pressing power, double-acting cylinders have both pressing and pulling power.

Advantages of double-acting cylinders

  • Most commonly used cylinder type
  • Energy-saving
  • Accuracy
  • Precision

What applications are best suited for double-acting cylinders?

  • Large scale engines
  • Industrial furnaces
  • Digging machines
  • Lift shafts
  • Steering mechanisms

Single-acting and double-acting cylinder suppliers

When it comes down to selecting which cylinder type is best for you, you need to weigh up the amount of control you require against what you can afford to have in place. For heavy lifting in one direction, single-acting cylinders are the way to go. However, if you’re moving something in two directions and require full control of the process, then double-acting cylinders are the best bet.

As leading cylinder manufacturers and suppliers, API Pneumatic UK has a broad portfolio of single-acting and double-acting cylinders to choose from, all at affordable prices and with quick turnarounds. Browse our pneumatic cylinder range online, or to discuss your specific cylinder requirements, why not chat to one our technical team on 01782 206 995 or email sales@apiuk.co.uk.