A pneumatic pump works by using compressed gas inside a chamber between two pistons that have different diameters. The chamber is pressurized, and in turn, more force acts upon the smaller piston. Because of this pressure, liquid moves through the system.
Pneumatic pumps are generally found in chromatography, or the separation of chemical mixtures, in which the pressures are used to analyze the components as they move through columns. The pneumatic pump is simpler and easier to use and maintain than other pumps, such as the syringe pump and hydraulic pump, with hydraulic pumps being even more powerful.