Cylinders that convert energy into linear motion can be powered by hydraulic fluid or compressed air. Hydraulic cylinders are usually the go-to option for seriously heavy-duty lifting and moving because hydraulics are very powerful and can provide tremendous holding strength. But for most industrial applications, the more agile air cylinder is often a better choice.
Air, or pneumatic, cylinders typically cost less upfront than hydraulic cylinders, and they are much less costly to maintain. They can be compact in size without sacrificing performance, and they offer an outstanding variety of configuration possibilities. (W.C. Branham can also custom-design pneumatic cylinders, if needed.)
Before you decide on the exact size and configuration that’s right for your project, though, you have to determine if you will need a single-acting unit or a double-acting air cylinder. Fortunately, that’s a pretty straightforward decision.
Single- vs. double-acting cylinders
The name says it all:
- A single-acting cylinder produces thrust that moves a load in one direction. The cylinder can be configured to either push a load forward or pull it backward at time of ordering. When it gets to the end of its “throw,” a spring or some similar mechanism returns the piston to its original position.
- A double-acting pneumatic cylinder produces thrust in two directions. So it can push a load up and then down, or back and forth. The cylinder has common porting at each end so compressed air can enter from one end to push and the other end to pull.
Deciding which one is right for your application depends on what you need to accomplish. If you require only single-direction movement, a single-acting cylinder is just the ticket. If you need to move a load in two directions under power, double-acting is the cylinder for you.
When to use a double-acting air cylinder
Theoretically, you could use two single-acting cylinders to separately produce push and pull motions. This could be a benefit in a situation where you require positive end-of-stroke positioning in both directions. In the vast majority of cases, though, a double-acting cylinder allows for more efficient design. These cylinders are stronger, faster, and more energy-efficient than single-acting cylinders and they come in longer stroke lengths, especially double-acting air cylinder types such as; Rodless Cylinders and Cable Cylinders.
Because double-acting pneumatic cylinders are very versatile, they can be used for:
- Opening and closing a gate, carwash or loading dock doors
- Opening and closing valves
- Moving items onto or off of conveyors
- Moving the conveyor systems themselves
- Silk screening
- Paint or Powder Coat Spraying
- Presses and punches
- Medical equipment
- The opening and closing shuttle bay doors on the International Space Station
Double-acting hydraulic cylinders are also used in a wide variety of non-industrial applications such as:
- Suspension systems in cars and other vehicles as well as airplane landing gears
- Earth-moving and other construction equipment
- Car transport carriers
While it may be easy to decide if you need a single- or double-acting cylinder, the options become much more complex after that. We’re happy to help you choose precisely the right configuration for your application, because finding Solutions in Motion is what we do here at W.C. Branham. Just give us a call.