1. SCOPE 1.1 These requirements cover single and double wall cylindrical steel tanks of the horizontal,
non-pressure type that are used for the underground storage of Flammable Liquids and
Combustible Liquids, such as gasoline, fuel oil, or similar products. 1.2 Part A of these requirements cover single wall tanks. 1.3 Part B of these requirements cover double wall tanks with provision for leak detection
monitoring of the interstice between the walls. 1.4 Part B also provides design criteria for the attachment of liquid tight containment
chambers to accommodate leak detection equipment and spill containment for product piping
systems. 1.5 These requirements cover tanks which are fabricated, inspected and tested for leakage
before shipment from the factory as completely assembled vessels. NOTE: For the requirements for tanks provided with corrosion protection at the factory, refer
to the Standard CAN/ULC-S603.1, Standard for Galvanic Corrosion Protection
Systems for Steel Underground Tanks for Flammable and Combustible Liquids. 1.6 These requirements do not cover tanks of capacities greater than 250 000 L. 1.7 The requirements of this Standard are for the construction of stationary tanks. The
installation of these tanks may be covered by any of the following: A National Fire Code of Canada, Part 4; B API 1615, Installation of Underground Petroleum Storage Systems; C CSA B139, Installation Code for Oil Burning Equipment; D NFPA 30, Flammable and Combustible Liquid sCode; and E Regulations of the appropriate authority having jurisdiction.