A liquid band vacuum pump is simple to operate and is utilized in several applications across various industries. A liquid ring pump works together with a sealant necessary in its operation. This liquid can be water, essential oil or any additional solvent which can be rotated by an impeller within the casing of the pump.
As the shaft turns, a liquid ring is established by the centrifugal force produced by the rotating impeller. This force holds the liquid ring against the inner wall structure of the pumping chamber. Since the impeller is situated eccentric to the pumping chamber, the depth of access 
of the blades in to the liquid ring reduces and improves as the impeller rotates. This creates increasing cellular quantity on the inlet slot side, creating vacuum.
On the Liquid-Ring Vacuum Pump discharge slot side, the impeller cell volume decreases as the blades move further in to the liquid ring. This increases the pressure until discharge occurs through the discharge port.
A continuing flow of new sealing liquid comes to the pump via the sealing-liquid inlet.
Regarding the two-stage liquid band pump, the discharge from the 1st stage does not discharge to atmosphere. Rather, the initial stage discharges through the manifold leading to the second stage in addition to through a discharge port located in the intermediate plate between the first- and second-stage impellers.