A liquid ring vacuum pump is easy to operate and is utilized in a number of applications across various industries. A liquid ring pump works together with a sealant necessary in its procedure. This liquid can be water, oil or any additional 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 push holds the liquid band against the inner wall structure of the pumping chamber. Since the impeller is located eccentric to the pumping chamber, the depth of access of the blades into the liquid ring reduces and increases as the impeller rotates. This creates increasing cellular volume on the inlet port 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 band. This increases the pressure until discharge takes place through the discharge port.
A continuous flow of fresh sealing liquid comes 
to the pump via the sealing-liquid inlet.
Regarding the two-stage liquid band pump, the discharge from the 1st stage will not discharge to atmosphere. Rather, the first stage discharges through the manifold leading to the second stage as well as through a discharge interface situated in the intermediate plate between the first- and second-stage impellers.