The air vacuum pump is a venturi-type AC pump that eliminates moisture from air-con systems, 
making it safe and simple to add refrigerant. The air vacuum pump is simple to work and pulls full vacuum within two a few minutes of being connected to an air line. Includes 1/2 in. ACME (R134a) and R12 connectors.
Air-driven vacuum pumps work when compressed air moving through an orifice increases its velocity and lowers its air pressure. Ambient atmosphere is used through channels in the generator, creating suction and vacuum. The atmosphere stream exits through the exhaust. … These functions require vacuum pumps.