Vacuum boosters matched with liquid ring pumps have higher capacity and can pump at lower pressures than liquid ring pumps alone. These systems are ideal for pumping wet gas mixtures at low pressures. Peak operation is available over a moderate pressure range.

A wide variety of two stage and three stage systems are available. Oil-filled systems can avoid problems with corrosive contaminants and vapor pressure of sealant liquid at low pressures with warm sealant.