A liquid band vacuum pump is easy to operate and can be used in several applications across various industries. A liquid band pump works together with a sealant necessary in its operation. This liquid could be water, oil or any various other solvent which is rotated by an impeller within the casing of the pump.
As the shaft turns, a liquid ring is created by the centrifugal force generated by the rotating impeller. This power holds the liquid ring against the inner wall of the pumping chamber. Since the impeller is located eccentric to the pumping chamber, the depth of access of the blades in to the liquid ring decreases and raises 
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 ring. This escalates the pressure until discharge occurs through the discharge interface.
A continuing flow of refreshing sealing liquid comes to the pump via the sealing-liquid inlet.
Regarding the two-stage liquid ring pump, the discharge from the initial stage will not discharge to atmosphere. Instead, the initial stage discharges through the manifold resulting in the second stage in addition to through a discharge port positioned in the intermediate plate between the first- and second-stage impellers.