A liquid ring vacuum pump is easy to operate and is used in a number of applications across various industries. A liquid ring pump works with a sealant required in its operation. This liquid could be water, essential oil or any various other solvent which is certainly rotated by an impeller within the casing of the pump.
As the shaft turns, a liquid band is Liquid-Ring Vacuum Pump established by the centrifugal force produced by the rotating impeller. This power holds the liquid ring against the inner wall structure of the pumping chamber. Because the impeller is situated eccentric to the pumping chamber, the depth of access of the blades in to the liquid ring reduces and raises as the impeller rotates. This creates increasing cellular volume on the inlet port side, creating vacuum.
On the discharge interface side, the impeller cell volume decreases as the blades 
move further in to the liquid ring. This escalates the pressure until discharge occurs through the discharge port.
A continuous 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 does not discharge to atmosphere. Instead, the initial stage discharges through the manifold resulting in the second stage in addition to through a discharge slot positioned in the intermediate plate between the first- and second-stage impellers.