Working principle and attributes:
The series HGL, HG pump is actually a type of single-stage and single-cylinder rotary piston vacuum pump. It can be enormously enhanced series H rotary piston pump and involves four patents; its basic capabilities have a good improvement.
Rotary piston vacuum pump is often a sort of vacuum manufacturing products suitable for pumping ordinary gases and condensable gases(when a fuel ballast made use of). The pump has to be fitted with proper equipment if gas is rich 
in oxygen, explosive, corrosive to ferrous metal, chemical reactive with vacuum pump oil.
Operation principle demonstrate in operating principle graph: A rotary piston with slide valve across ecentric wheel driven by shaft in the housing. Piston pole can slide and swing freely in arch track. The whole pump chamber is divided into chamber A and chamber B by piston. When shaft rotates the volume of chamber A and chamber B are modified repetitively, so that pumping goal can be attained.
The series HGL, HG pump can be a backing pump when mixed with an additional substantial vacuum pump as well as operate singly. It's widely used in vacuum smelting, vacuum drying, vacuum impregnation and large vacuum simulation testing,etc.
