vertical or horizontal multistage centrifugal pump, two or more impellers to have high pressure. A multistage pump is a type of centrifugal pump that combines the suction and discharge sections with the intermediate sections through connecting rods. It can generate high water output pressure and relies on the rotation of the impeller to create centrifugal force, thereby transporting materials. When the gas density reaches the operating range of the mechanical vacuum pump, it is extracted, gradually achieving a high vacuum. The multi-stage pump operates by changing the volume of the pump chamber to achieve suction, compression, and discharge, making it a variable-volume centrifugal pump