It is a mechanical pump with high evacuating speed also referred to as mechanical reinforcing pump. Fast start with speedy evacuation in the vacuum condition of 1000~1Pa, it can achieve its ultimate pressure within a shortest possible time. But it can not operate individually. It must be in combination with its fore stage pump that makes it possible to start work by making the pressure permissible at its inlet.

          It is widely used in vacuum coating, metallurgical industry for degassing, vacuum treatment for molten steel and vacuum simulation for space chamber or space capsule, etc, in chemistry, food, medicine, motor making industries as well as distilling, evaporating and dry process.