Vac Pumps

Vac Pumps

Vacuum pumps are often made of stainless steel because of the material's strength and resistance to contamination. Vacuum pump tubing, gaskets and other parts are made from materials that resist cracking or degradation while maintaining the vacuum's seal. Vacuum pumps can be found in laboratories as well as in industrial and medical technology development settings. They are used in the production of electric lamps and vacuum tubes, which are used in microwaves. Manufacturers install integral vacuum pumps in vehicles with hydraulic brakes and camshafts. Vacuum pumps are also necessary for creating the vacuums in which semiconductor processing, electron microscopy and the production of analytical instrumentation takes place. Surgical procedures require vac pumps to provide suction. Pneumatic air supply, gas chromatography and air quality samplers also rely on vacuum pumps.

There are three main kinds of vac pumps: positive displacement, momentum transfer and entrapment pumps. Though all of the configurations are different, they each operate according to the same principles. Positive displacement pumps expand one part of a vacuum chamber while compressing the gas inside and exhausting it. Momentum transfer pumps cause repeated collisions between gas molecules and rotors or steam jets that direct the molecules out of the chamber. Entrapment pumps use condensation created by rapid heating and cooling to compress and trap gas molecules in a solid or absorbed state. Within each of these categories, a given vac pump can operate by dry or wet processes. Oil-lubricated vac pumps can operate at high levels because the presence of oil enhances the seal between moving parts. A downstream oil separator is necessary, however, to prevent the intake of oil and contamination of the vacuum or evacuated air. Medical pumps, for example, are usually oilless; the smallest trace of oil in the vacuum could cause pump malfunction or threaten the health of a patient. Pumps that do not use oil are called dry vacuum pumps and are more common than oil pumps. They are generally less expensive in terms of initial investment and continuing maintenance costs, though their vacuum generation ability is generally lower than that of wet vacuum pumps.