[tr6scott]

A couple of finer details to consider.

If you are working with the constraints of only using tanks, remember you have to feed the cylinder on both the extend and retract if it is a repetitive motion. In these situations, it may be favorable to look at cylinder that has a spring to return for one of the motions, so you don't have to supply air from the tank to return the cylinder.

Also there is what is called rod end of the cylinder. This is the side the working arm attaches to the piston in the cylinder. The working area on the rod end, is the area of the cylinder bore, less the area of the rod bore. So the rod end has less force at the same psi. Also the volume of air is less on the rod end of the cylinder.