Liquid Band Vacuum Pump Working Theory. The vacuum pump consisting an impeller which is located eccentric to 
the cylinder body(Vacuum pump casing). Vacuum is created in the vacuum pump by using a liquid seal. … When the impeller starts to rotate, the liquid is usually starts move outward by centrifugal pressure.
Water band vacuum pump is a common kind of liquid band vacuum pump. Water band is certainly a rotor with Water Vacuum Pump multi-blades eccentrically set up in the pump shell. When it rotates, it throws liquid into the pump and forms a liquid ring concentric with the pump shell. The liquid ring and the rotor blade form a rotating variable capability vacuum pump with periodic quantity change. When the functioning liquid is water, it is called water Ring vacuum pump. There are several kinds of water ring vacuum pumps with different prices. .Among them, 2BV is more cost-effective. The type selection of water ring vacuum pump should be based on your on-site procedure, the required vacuum level and the amount of air pumping required.