We also deals with Double Acting Pneumatic Cylinders which operate on both ends of the piston, one element is used for the out stroke, while the other is used for in-stroke. These Double Acting Cylinders are commonly used in machinery such as steam engines, which is known as an external engine. This is because double acting pneumatic cylinders produce force from both ends of the piston. The Working Pressure of these pneumatic cylinders are 2 bar to 10 bar.