The air vacuum pump is a venturi-type AC pump that eliminates moisture from air-con systems, which makes 
it safe and easy to add refrigerant. The atmosphere vacuum pump is simple to operate and pulls full vacuum within two minutes of being linked to an air collection. Contains 1/2 in. ACME (R134a) and R12 connectors.
Air-powered vacuum pumps work when compressed air passing via an orifice increases its velocity and lowers its air pressure. Ambient surroundings is drawn in through stations in the generator, creating suction and vacuum. The air stream exits through the exhaust. … These operations require vacuum pumps.