A liquid ring vacuum pump is easy to operate and is used in a number of applications across various industries. A liquid band pump works together with a sealant needed in its procedure. This liquid could be water, oil or any other solvent which is usually 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 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 entry of the blades into the liquid ring decreases and raises as the impeller rotates. This creates increasing cellular volume on the inlet interface side, creating vacuum.
On the discharge interface side, the impeller cell volume decreases as the blades move further into the liquid ring. This escalates the pressure until discharge takes place through the discharge slot.
A continuous flow of refreshing sealing liquid comes to the pump via the sealing-liquid inlet.
In the case of the two-stage liquid band pump, the discharge from the first stage does not discharge to atmosphere. Instead, the first stage Liquid-Ring Vacuum Pump discharges through the manifold resulting in the second stage as well as through a discharge slot situated in the intermediate plate between the first- and second-stage impellers.