The air vacuum pump is a venturi-type AC pump that eliminates moisture from air conditioning systems, which makes it safe and easy to add refrigerant. The atmosphere vacuum pump 
is easy to run and pulls complete vacuum within two moments of being linked to an air range. 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 procedures require vacuum pumps.