Abstract: A pump system especially suitable for pumping out liquids from tank enclosures. A liquid pump, Preferably powered by pressurized gas such as compressed air or natural gas from a nearby well, is mounted in a tubular member frame. The rate of pressurized gas flowing to the pump, and consequently the liquid pumping rate, is controlled by a limit valve, lever arm, and float assembly. As the liquid level increases, the float rises and the lever arm opens the limit valve, permitting a higher rate of pressurized gas flow and higher pump rate. At least some components of the frame have liquid inlet openings, which permit liquids to enter the frame, and the frame serves as a conduit to carry the liquids to the intake of the pump.