A vacuum pump is a pump that removes molecules of air and gas from a sealed volume leaving behind a partial vacuum. Vacuum pumps are also able to move water or fluids from one area to another. Vacuum pumps can also be called suction pumps. Find out more in our complete guide to vacuum pumps.Types of Vacuum PumpsMomentum transfer pump – This is where the air or gas is transferred from the inlet to the exhaust side of the pump. This is done by a mechanical rotating part that accelerates the gas molecules from the vacuum side to the exhaust side.Entrapment pump – These pumps capture gases in a confined space. They are cooled and condensed and then removed in a solid state. An ion pump will use electrical fields to ionise the gases into a solid state.Positive displacement pump – This vacuum pump has an expanding cavity on the suction side of the pump and a decreasing cavity on the discharge side. The same volume is moved in each cycle so it delivers consistent capacities. These pumps are suited to applications that need moderate flow and moderate pressure like food manufacturing industries. Positive displacement pumps guarantee constant speed and flow.Diaphragm pump – These work in a similar way to positive displacement pumps and are often used for fluid transfers. These pumps consist of two diaphragms that flex forwards and backwards which causes the volume in the pump chamber to increase and decrease. A valve then stops a reverse flow of the fluid. Diaphragm pumps are used in many industries for filling and dispensing as they are very accurate.Vacuum Pump Applications:Semiconductor processingAir conditioningFlight instrumentsComposite mouldingUranium enrichmentPrint pressesMedical applications