Flojet air operated diaphragm pumps offer excellent self-priming capability. pumps can be located above the supply tank. suction-side foot valve is recommended for best operation. liquid pressure is regulated by supply air pressure. no bypass or pressure relief plumbing is necessary. choice of santoprene, Buna, or viton elastomers provide a wide range of chemical compatibility. Quick disconnect liquid and gas port fittings provided for easy installation.