The tank serves as a barrier fluid cooler. For this purpose, a pipe system is placed inside it, through which a cooling medium is pumped. The barrier liquid enters the tank in its upper part from the side, is cooled, passing from top to bottom, and leaves the tank through the fitting in the bottom. The bottom also has a fitting for draining sediment, removing the barrier liquid, and flushing during periodic and unscheduled maintenance of the tank.