Water ring type vacuum pumps are a type of vacuum pump that uses a rotating impeller to create a vacuum. They are commonly used in industrial and commercial applications to create a vacuum in a sealed system, They are also used in many laboratory and medical applications. Water ring type vacuum pumps are reliable, efficient, and cost-effective. They are also easy to maintain and operate. This makes them an ideal choice for many applications.

Vacuum pumps are simply compressors that take in gas at a pressure lower than atmospheric pressure, compress it, and discharge the gas at atmospheric pressure. Since gas at low pressures has a large volume, vacuum pumps tend to be bulky. Steam jet ejectors are extensively.

Liquid-ring pumps are typically used as vacuum pumps, but can also be used as gas compressors. The function of a liquid-ring pump is similar to a rotary vane pump, with the difference being that the vanes are a rigid part of the rotor and churn a rotating ring of liquid to form the compression-chamber seal. They are an inherently low-friction design, with the rotor being the only moving part. Sliding friction is limited to the shaft seals. Liquid-ring pumps are typically powered by an induction motor.