Vacuum pumps are used in many industrial and scientific processes including: Composite Plastic moulding processes (VRTM) Driving some of the flight instruments in older and simpler aircraft without electrical systems. The production of most types of electric lamps, vacuum tubes, and CRTs where the device is either left evacuated or re-filled with a specific gas or gas mixture Semiconductor processing, notably ion implantation, dry etch and PVD, ALD, PECVD and CVD deposition and soon in photolithography Electron microscopy Medical processes that require suction Uranium enrichment Medical applications such as such Radiotherapy, Radiosurgery, Radiopharmacy Analytical instrumentation to analyse gas, liquid, solid, surface and bio materials Mass spectrometers to create an ultra high vacuum between the ion source and the detector Vacuum coating on glass, metal and plastics for decoration, for durability and for energy saving, such as low-emissivity glass Hard coating for engine components (as in Formula One) Ophthalmic coating Milking machines and other equipment in dairy sheds Air conditioning service - removing all contaminants from the system before charging with refrigerant Trash compactor Vacuum engineering Sewage systems (see EN1091:1997 standards) Freeze Drying Vacuum may be used to power, or provide assistance to mechanical devices. In diesel engined motor vehicles, a pump fitted on the engine (usually on the camshaft) is used to produce vacuum. In petrol engines, instead, vacuum is obtained as a side-effect of the operation of the engine and the flow restriction created by the throttle plate. This vacuum may then be used to power: The vacuum servo booster for the hydraulic brakes Motors that move dampers in the ventilation system The throttle driver in the cruise control servomechanism In an aircraft, the vacuum source is often used to power gyroscopes in the various flight instruments. To prevent the complete loss of instrumentation in the event of an electrical failure, the instrument panel is deliberately designed with certain instruments powered by electricity and other instruments powered by the vacuum source. Source: wikipedia
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http://en.wikipedia.org/wiki/Vacuum_Pump