The Hydratron Double Acting Air Driven Gas Booster is a reciprocating, positive displacement gas pump with a directly coupled, integral linear reciprocating air motor, designed to generate high-pressure gas output. With double acting models, the pressure increase is made possible by means of the area ratio between the larger diameter air drive piston directly connected to two smaller diameter gas pistons having the same diameter as each other. The reciprocating action of the gas booster draws gas at low pressure into the booster then displaces the gas at a higher pressure output from the booster into a closed system. On double acting models, the inlet gas pressure is used to provide additional energy allowing greater output pressures and higher flow rates to be achieved. All Models can easily be incorporated into easy to operate Standard System gas power/transfer units.