UN portable ISO tank containers have uniform external appearances, and the construction materials, linings, and fittings vary. Tank containers are classified according to the products carried and are commonly grouped in categories and referred to as CHEMICAL, FOOD-GRADE, GAS, and BITUMEN tanks. SWAB BODY tanks are exclusively used on the European continent, with larger capacities. The tank container is a pressure vessel mounted in a frame. Frame dimensions comply with the International Standard Organization (ISO) guidelines and are constructed following uniform international regulations for the carriage of bulk cargoes by truck, train, or ship.
Standard exterior frame dimensions on all ISO tank containers are 20' long by 8' wide by 8'6' high (609 cm x 259 cm x 243 cm). The Swab Body tanks have different dimensions. Corner castings are in each of the 8 corners, similar to standard cargo containers. Tank containers range in size from 20,000 (5283 US gallons) to 26,000 liters (6868 US gallons) and are available as insulated or non-insulated units, with or without steam-heat capability. There are many variations on these themes, such as the Swab Tank container mainly utilized in domestic European trade lanes in sizes up to 35,000 liters and special tanks for the carriage of Bitumen.
The most common frame types available - BEAM TANK - The end frame utilizes the inherent strength of the tank cylinder as a beam. FRAME TANK - The full frame supports the cylinder within a steel frame.
