Several types of vacuum pumps commonly used in the pharmaceutical industry - vacuum pumps commonly used in the pharmaceutical industry can be simply divided into variable displacement vacuum pumps and jet vacuum pumps. Variable displacement vacuum pumps are devices that use the periodic changes in pump chamber volume to complete suction and exhaust. Reciprocating vacuum pumps, rotary vane vacuum pumps, slide valve vacuum pumps, water ring vacuum pumps, and Roots vacuum pumps belong to variable displacement vacuum pumps. Jet vacuum pump is a momentum transfer pump that uses the pressure drop generated by the Venturi effect to transport gas to the outlet through high-speed jets. Water jet vacuum pump, steam jet vacuum pump, steam water series jet vacuum pump, and steam water combination jet vacuum pump all belong to jet vacuum pumps.