In order, in a pressure accumulator, to generate a required operating pressure
of a fluid situated in the pressure accumulator, a heater device is provided, disposed
in an upper region of the pressure accumulator. The device generates a vapor cushion
and the required operating pressure. Where necessary, when the fluid flows out,
the pressure in the pressure accumulator is automatically reduced after the level
has fallen below a defined filling level, as a result of the vapor condensing at
a cold insulating device with a high heat-accumulation capacity. The pressure accumulator
is preferably used as an emergency shut-down tank or as an emergency accumulator
in a nuclear power plant.
