Datasheet: Double Wall Aboveground Fuel Storage Tank (2500)Source: BakerCorp
These tanks are designed for diesel or heavier fuels. They are not for gasoline. The tank is a double wall design having one cylindrical tank inside another. There is a small annular area between the two tanks that will contain any leakage from the inner tank, preventing liquid from reaching the environment. The annular area can be monitored for leakage. These tanks are fitted with emergency vents and an overfill alert. Some tanks are fitted with electric dispensing pumps. These tanks are UL-142 and UL-2244 listed.