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