Industrial Vacuum Pumps Rotary vane: Rotary vane pumps are comprised of a number of vanes that are mounted to a rotor that turns inside a cavity. As the vanes rotate, centrifugal power extends them from their individual slots, forming compression cells that get larger to draw atmosphere in from the intake and smaller to force air flow out the exhaust.
Articulated piston: An articulated piston commercial vacuum pump functions in a way similar compared to that of an automobile engine. As the piston techniques downward in the cylinder, atmosphere is used through the intake valve. During the piston’s upward stroke, the surroundings is permitted to flee via an exhaust valve. Two spring-backed piston rings are accustomed to seal the piston to the cylinder.
Screw: Rotary screw pumnps include two parallel rotary screws in the pump casing. The screws are synchronized to turn in opposing directions, which in turn causes the compression action to occur. The gas is definitely compressed in direction of the pump’s discharge 
port.
Liquid ring: Liquid ring pumps also operate via positive displacement. During operation, the pump’s impeller rotates within the pump casing. A rotating liquid band then seals the impeller and its blades. Liquid can be sucked into the compression chamber to keep the ring stable. Conveyed gas can be compressed during each impeller revolution.
Claw: Claw vacuum pumps consist of two rotors that are extremely close but usually do not are exposed to one another during rotation. As the rotors switch they actually enlarge the space between them to attract air, then because they rotate around, actually reduce the space between them to compress the air out of the chamber.