Abstract: A liquid ring fluid flow machine is presented. The machine includes a stationary annular housing having an outer surface and an inner surface. The inner surface defines a chamber that is arranged to receive a liquid. A rotor having a core and a plurality of radially extending vanes is eccentrically rotatably mounted within the chamber for directing the liquid into a recirculating liquid ring in proximity to the inner surface of the housing within the chamber. The inner surface of the housing that is in contact with the recirculating liquid ring is covered by a hydrophobic coating. The machine further includes a first supply pipe and a second supply pipe, each in fluid communication with the chamber.