Liquid ring vacuum pumps are a single stage block model, suitable to compress gas and vapours in the industrial processes. The main features are: - able to pump gases and vapours; - nearly isothermal compression of gases; - no lubricant in contact with pumped gas; - the pumps must be continuously fed with service liquid, normally water (oil, organic liquids etc. can be used), while working in a sufficient rate to eliminate the heat produced by the compression of gases and to replace any liquid which flows out of the pump together with the gas. The service liquid can be separated from the gas in a liquid separator and can be recirculated either partially or entirely, after intermediate cooling; - safe operation and minimum maintenance; - reduced noise and vibration. The liquid ring vacuum pumps range includes the following sizes: - RVS 3÷16 /M directly coupled to the flange of an electric motor and the impeller is supported by the electric motor standard bearings; - > RVS 17÷21 /SG are supported by a bearing support with two sealed bearings life lubricated with grease; - RVS 23÷60 /CT bearing support with bearings grease lubricated.