Rodionov Yu.V., Zakharzhevsky S.B., Vorobyov V.B., Nikitin D.V., Shestakov V.E.Calculation of Operating Speed for Two-Stage Liquid Sliding-Vane Vacuum Pump // Journal "Problems of Contemporary Science and Practice" Vernadsky University , Tambov. TSTU publisher house , 2012. (pdf-file) Abstract: The paper deals with the calculation of operating speed for liquid sliding-vane vacuum pump and stating the loss factor. The mathematical model of real gas flow through the hinge seal is given. The paper presents the laboratory-scale set-up for calculating experimentally the volume of gas leakage through the hinge seal.