building an energy conserving pneumatic system

[Rafael2215]

Hi,
We were wondering whether it is possible to build a pneumatic system that conserves the air it's using, meaning that after the first pressurization of the tanks, made by the compressor, there will be no need for any more pressurizations for the remainder of the match, that is you start the compressor only once at the begginnig of the match and stop it when the pressure in the tanks reaches 115 psi (this being achieved by having the same volume of air leaving the piston at one end entering the piston at the other end simultaneously).
If it is possible, can anyone shed some light about how to build such a system?

Thanks,
Team 2215