Rotary piston vacuum pump is suitable for pumping air and
other ordinary gases, when a gas ballast valve is used it can also
pump condensable gases. The pump must be fitted with appropriate
accessories if gas is rich in oxygen, explosive, corrosive to
ferrous metal, chemical reactive with vacuum pump oil. The HGL, HG
pump can be operated singly or as a backing pump combined with
other high vacuum pump, such as diffusion pump and oil booster
pump. It is widely used in the industry of vacuum coating, vacuum
heat treatment, vacuum impregnation, vacuum smelting, vacuum drying
and molecular distillation .
