Piston pumps are used for most large level vacuum applications. These pumps have got a sliding sleeve by which the gas enters, then drawn into a cylindrical chamber and exhausted by a Rotary Piston Vacuum Pump china rocking piston plunger. These pumps are very hardy and also have pumping speeds that range from 15 cfm to 2,000 cfm and the pumps can reach a pressure of 1 
1 x 10-4 Torr. Rotary piston pumps can be prepared for corrosive and oxygen service.