A cryogen storage vessel at an installation is filled with liquid cryogen from a liquid cryogen storage tank that has a pressure lower than that of the vessel. After headspaces of the vessel and tank are placed in fluid communication with another via a gas transfer vessel and are pressure-balanced, a pump in a liquid transfer line connected between the tank and the vessel is operated to transfer amounts of liquid cryogen from the tank to the vessel via the liquid transfer line and pump as amounts of gaseous cryogen are transferred, through displacement by the pumped cryogenic liquid, from the vessel to the tank.