Creating a vacuum in a system requires moving all molecules of gas out of the system. Molecules will only move if there is a difference in pressure between two regions. The region that has the smaller number of molecules will be the low pressure region and the area with more molecules will be considered the high pressure. A device that can induce pressure difference between two regions of space is considered a pump. In a certain system, the pump that creates a vacuum is considered a vacuum pump.
There are two types of vacuum pumps, one being a transfer pump and the other being a trapping pump. The transfer pump, which is also called a kinetic pump since the gas is being pushed that the gas is transferred from the inlet of the pump to the outlet. This is often done by a mechanically moving part of the pump that often rotates, accelerating the molecules of the gas and making the region of low pressure. When the level of vacuum is reached the tank is isolated by a high vacuum valve. Any exchange of gas between the container and the pump is stopped by the valve.
A trapping pump, also known as a capture pump, is usually located in the container that is being evacuated. The pump removes the gas molecules by sorption or condensation on the internal surface. If the gas molecules come in contact with the refrigerated surface of the pump, the gas will be condensed and removed as a liquid.
Vacuum pumps can be damaged over time and basic maintenance is needed to keep the equipment up and running. Vacuum pump repair is offered throughout the country and a number of different companies may operate in your area. Reviews on many of these companies can be found on different websites throughout the web.