A system for deaeration of a liquid comprises a heater for heating the liquid to a well-defined temperature, means for pressurizing the liquid, a first piping for guiding the heated liquid to a separation vessel, a vacuum pump for evacuating deaerated gases from the separation vessel, and a second piping for guiding the deaerated liquid from the separation vessel. The system further comprises an inert-gas supply and a mixer for supplying and mixing in inert gas into the liquid in the first piping. The vacuum pump is controllable to maintain a separation pressure in the separation vessel corresponding to a pressure at or slightly above the saturation pressure.
