Abstract: The present invention relates to a fluid reservoir (21), said fluid reservoir (21) comprising at least one first cavity (29) and one second cavity (30) in fluidic communication with each other and adapted to accommodate fluid (7), the fluid reservoir (21) further being connected to a fluid-container system (7, 8, 9, II, 22), a fluid consumer (5) in fluidic communication with at least the second cavity (30), a pressurization system (I, 2) adapted to generate a substantially constant pressure, and a vacuum system (58, 59, 60) adapted to generate a pressure below ambient pressure. The invention further comprises a fluid-supply system.