A liquid band vacuum pump is easy to operate and is utilized in several applications across various industries. A liquid band pump works with a sealant necessary in its operation. This liquid could be water, oil or any additional solvent which can be rotated by an impeller within the casing of the pump.
As the shaft turns, a liquid band is established by the centrifugal force generated by the rotating impeller. This pressure holds the liquid ring against the inner wall of the pumping chamber. Since the impeller is situated eccentric to the pumping chamber, the depth of entry of the blades into the liquid ring reduces and increases as the impeller rotates. This creates increasing cellular volume on the inlet slot side, creating vacuum.
On the Liquid-Ring Vacuum Pump china discharge slot side, the impeller cell volume decreases as the blades move further into the liquid band. This increases the pressure until discharge occurs through the discharge slot.
A continuous flow of new sealing liquid comes to the pump via the sealing-liquid inlet.
In the case of the two-stage liquid ring pump, the discharge from the 1st stage will not discharge to atmosphere. Instead, the 1st stage discharges through the manifold resulting in the second stage in 
addition to through a discharge slot situated in the intermediate plate between your first- and second-stage impellers.