Vacuum pumps are devices that can be used to remove both air and gases from a tightly closed container. While an absolute vacuum is difficult to achieve, an acceptable partial level of vacuum is suitable for many applications. Vacuum pumps and the removal process are used in various industries such as the scientific, medical, automobile, aerospace, and machinery sectors. They are used for things such as: vacuum tubes, electric lamps, cathode ray tubes, ion implantation in semiconductor applications, electron microscopes, throttle controllers for a car's cruise control, power brake boosters, gyroscopes in airplanes, lab experiments and testing environments, special parts testing, and analysis, etc.
Vacuums are measured in kPa, torr or mm of HG. To ensure greater levels of vacuum, several pumps can be connected in a series. High-flow vacuums generally have lower vacuum and low-flow vacuums usually have higher vacuum. Vacuum pumps come in assorted sizes with the larger pumps usually being used for continuous pumping. Smaller pumps are generally more efficient however they tend to easily over heat if they are over used.
If you are going to run your pump quite a lot it’s probably better to use one that is made to operate constantly instead of one that may overheat. The type of pump lubrication can lower the operating noise and vibration of the unit however it will raise the cost and increase the size of it. Oil lubricated pumps usually last longer though.
There are several types of vacuum pumps such as: venturi vacuum pumps, entrapment pumps, transfer pumps, diaphragm, rocking-piston, reciprocating-piston, liquid-ring, rotary-screw, rotary-vane, lobed-rotor, cryo pump rubber, plastic-sealed piston pumps, turbo molecular pumps, scroll pumps, roots blower, rotary compression pumps, diffusion pumps, and ion pumps, etc. These pumps sometimes require more than one chamber to achieve optimum vacuum rating. Venturi pumps use a flow of compressed air, liquid or other gases to pull or create a vacuum.
Vacuum pumps are rated by their pumping speed, their class of vacuum, and the number of stages required, etc. These pumps are more power efficient than air compressors and if they are properly maintained they should last you for quite some time.