RSS screw vacuum system is high vacuum system, which consist of RV roots vacuum pump as main pump and DPSB screw vacuum pump as backing pump in series, take the advantages of high vacuum, compact structure, convenient for operate. It is suitable to pumping all kind gas and solvent vapor, and weak corrosive gas. Widely used in big pumping speed and all kinds of high vacuum systems, such as scientific experiments, chemical and pharmaceutical, vacuum smelting, vacuum coating, semiconductor, electrical equipment and so on.