Double-skin vertical cylindrical tanks made in carbon steel quality S 235 JR according to UNI EN 10025 and provided with structural steel feet. Tanks are made with shell plates and dished ends assembled according to a certified welding process. Each tank is pressure - tested at 1 bar or 0.5 bar for the interstitial space and are provided with a calibration table. This type of tank represents an ideal solution for storage or refuelling stations where safety and environmental protection are strictly required.