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