Rotary vane: Rotary vane pumps are made up of a series of vanes that are mounted to a rotor that turns inside a cavity. As the vanes rotate, centrifugal push extends them from their individual slots, forming compression cellular material that get larger to draw air flow in from the intake and smaller to drive atmosphere out the exhaust.
Articulated piston: An articulated piston industrial Industrial Vacuum Pumps vacuum pump operates in a way similar compared to that of an automobile engine. As the piston techniques downward in the cylinder, surroundings is used through the intake valve. During the piston’s upward stroke, the air is permitted to escape 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 housing. The screws are synchronized to turn in reverse directions, which causes the compression action to occur. The gas is compressed in the direction of the pump’s discharge port.
Liquid ring: Liquid ring pumps also operate via positive displacement. During procedure, the pump’s impeller rotates inside the pump casing. A rotating liquid band after that seals the impeller and its blades. Liquid is sucked in to the compression chamber to keep the ring stable. Conveyed gas is definitely compressed during each impeller revolution.
Claw: Claw vacuum pumps contain two rotors that are very close but do not come in contact with one another during rotation. As the 
rotors switch they actually enlarge the area between them to draw in air, then because they rotate around, physically decrease the space between them to compress the air flow out from the chamber.