Tandem cylinders are two separate double acting air cylinders arranged in line to one cylinder body so that the power generated by the two is added together.
Thereby approximately doubling the piston output.
A tandem cylinder is used in applications where a large amount of force is required from a small-diameter cylinder.
Basically, a tandem cylinder is simply two or more separate cylinders stacked end to end in a unit and with all the pistons mounted on a common piton rod.
Pressure is applied to both pistons, resulting in increased force because of the larger area.