The peculiarity of this type of tank is the presence of a floating cover, provided with arm and lifting device; the fundamental characteristic is that the floating cover remains constantly on contact with the upper surface of the product, in order to avoid the air presence inside the container, and consequently no oxidation of the liquid-food; this solution allows to maintain the integrity of the products, to whom has the necessity to store small quantities, without the need to realize a nitrogen inertisation system only for some tanks, avoiding significant costs.