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 surroundings vacuum pump is simple to work and pulls full vacuum within two mins of being linked to an air collection. Includes 1/2 in. ACME (R134a) and R12 connectors.
Air-powered vacuum pumps work when compressed air passing through an orifice increases its velocity and lowers its air pressure. Ambient atmosphere is drawn in through stations in the generator, creating suction and vacuum. The air flow stream exits through the exhaust. … These procedures require vacuum pumps.