ULC 653

This Standard covers steel contained tank assemblies that are used for aboveground storage of flammable and combustible liquids such as gasoline, fuel oil, or similar products with a relative density not greater than 1.0.Contained tank assemblies consist of primary tanks contained within steel containments having capacities of not less than 110% of the capacities of the primary tanks. The calculation of this capacity includes any part of the primary tank that would be submerged in the containment. The minimum design of the containment shall be such that any leak from a perforation in the lower half of the primary tank shall be contained. This Standard does not cover requirements for accessory devices and appurtenances such as overfill protection, spill containment and sumps.