11 Apparatus for heating, steam generating, cooking, refrigerating, drying, ventilating, water supply and sanitary purposes; overflow tanks for central heating systems; refrigerating containers; containers included in this class; hot water cylinders, heating buffer storage tanks, stratified buffer storage tanks, high-capacity storage tanks, combination storage tanks, buffer storage tanks, solar storage equipment, special storage tanks, heat pump storage tanks, underground storage tanks, baking oven containers; fire bowls