Rotary vane: Rotary vane pumps are comprised of a series of vanes that are mounted to a rotor that turns in the cavity. As the vanes rotate, centrifugal pressure extends them from their individual slots, forming compression cellular material that get larger to draw air flow in from the consumption and smaller to press air flow out the exhaust.
Articulated piston: An articulated piston commercial vacuum pump operates in a manner similar compared to that of a car engine. As the piston movements downward within the cylinder, surroundings is drawn in through the consumption valve. During the piston’s upward stroke, the surroundings is permitted to escape via an exhaust valve. Two spring-backed piston bands are used 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 actions that occurs. The gas is certainly compressed in the direction of the pump’s discharge slot.
Industrial Vacuum Pumps Liquid ring: Liquid ring pumps also operate via positive displacement. During procedure, the pump’s impeller rotates in the pump casing. A rotating liquid band then seals the impeller and its blades. Liquid is 
usually sucked in to the compression chamber to keep carefully the ring steady. Conveyed gas can be compressed during each impeller revolution.
Claw: Claw vacuum pumps consist of two rotors that are very close but do not are exposed to each other during rotation. As the rotors switch they actually enlarge the area between them to draw in air, then as they rotate around, actually decrease the space between them to compress the air flow out from the chamber.