A method for retaining the temperature of a liquid in a liquid distribution system having at least one liquid conduit extending from a liquid source (2,22,6) to a liquid tap provided with a valve device having a gas valve unit (110,116) and a liquid valve unit, comprising the steps of - evacuating the liquid from the liquid conduit after completion of a tapping operation, by generating a backward pressure gradient in said liquid conduit, causing the liquid to flow backwards towards said liquid source, while letting a gas flow into the liquid conduit and replace the backwardly flowing liquid therein, - stopping said backward flow of liquid when the liquid conduit is evacuated, and - evacuating the gas from the liquid conduit when liquid is to be tapped again from said liquid tap, by generating a forward pressure gradient in said liquid conduit causing the liquid to flow from said liquid source to said liquid tap, - said step of evacuating the gas from the liquid conduit and refilling of liquid in said liquid conduit being performed in three steps: - a first step, initiated by said liquid tap being activated, the activation of the liquid tap causing a change of a physical variable, said change being sensed by a sensor (15,16; 120,121,130; 120a,130a; 120b,130b) so as to initiate a second step, - said second step involving refilling the liquid conduit with liquid from said liquid source, while permitting remaining gas to escape via a gas passage in said gas valve unit being separate from a liquid passage in said liquid valve unit, and - a third step, initiated when the liquid reaches said liquid tap, involving opening said liquid passage so as to permit liquid to flow out via said liquid passage and through said liquid tap, characterized in that, at the end of said second step of refilling the liquid conduit with liquid from said liquid source, the motion of liquid will be dampened, when it approaches said valve device, by means of - either a compressible volume of gas located in front of the moving liquid adjacent to said gas valve unit, said compressible volume of gas being compressed when it is pushed forward and is trapped inside or outside an inner tubular body disposed in an end portion of said liquid conduit, or - a container forming part of a closed gas system, said gas passage communicating with a closed volume of pressurized gas. - evacuating the liquid from the liquid conduit after completion of a tapping operation, by generating a backward pressure gradient in said liquid conduit, causing the liquid to flow backwards towards said liquid source, while letting a gas flow into the liquid conduit and replace the backwardly flowing liquid therein, - stopping said backward flow of liquid when the liquid conduit is evacuated, and - evacuating the gas from the liquid conduit when liquid is to be tapped again from said liquid tap, by generating a forward pressure gradient in said liquid conduit causing the liquid to flow from said liquid source to said liquid tap, - said step of evacuating the gas from the liquid conduit and refilling of liquid in said liquid conduit being performed in three steps: - a first step, initiated by said liquid tap being activated, the activation of the liquid tap causing a change of a physical variable, said change being sensed by a sensor (15,16; 120,121,130; 120a,130a; 120b,130b) so as to initiate a second step, - said second step involving refilling the liquid conduit with liquid from said liquid source, while permitting remaining gas to escape via a gas passage in said gas valve unit being separate from a liquid passage in said liquid valve unit, and - a third step, initiated when the liquid reaches said liquid tap, involving opening said liquid passage so as to permit liquid to flow out via said liquid passage and through said liquid tap, - a first step, initiated by said liquid tap being activated, the activation of the liquid tap causing a change of a physical variable, said change being sensed by a sensor (15,16; 120,121,130; 120a,130a; 120b,130b) so as to initiate a second step, - said second step involving refilling the liquid conduit with liquid from said liquid source, while permitting remaining gas to escape via a gas passage in said gas valve unit being separate from a liquid passage in said liquid valve unit, and - a third step, initiated when the liquid reaches said liquid tap, involving opening said liquid passage so as to permit liquid to flow out via said liquid passage and through said liquid tap, - either a compressible volume of gas located in front of the moving liquid adjacent to said gas valve unit, said compressible volume of gas being compressed when it is pushed forward and is trapped inside or outside an inner tubular body disposed in an end portion of said liquid conduit, or - a container forming part of a closed gas system, said gas passage communicating with a closed volume of pressurized gas.