Steel Underground Tanks for Flammable and Combustible Liquids
1.1 These requirements cover horizontal atmospheric-type steel tanks intended for the storage underground of flammable and combustible liquids.
1.2 These requirements cover single wall tanks, secondary containment tanks, multiple compartment single wall and multiple compartment secondary containment tanks.
1.3 The tanks covered by these requirements are intended for installation in accordance with the National Fire Protection Association Standard for the Installation of Oil-Burning Equipment, NFPA 31, the Flammable and Combustible Liquids Code, NFPA 30, the Automotive and Marine Service Station Code, NFPA 30A, the Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines, NFPA 37, the Fire Code, NFPA 1, and the International Fire Code, published by the International Code Council.
1.4 Tanks covered by these requirements are cylindrical tanks that are fabricated, inspected, and tested for leakage before shipment from the factory as completely assembled vessels.
1.5 These requirements do not apply to tanks covered by the Standard for Welded Steel Tanks for Oil Storage, API 650, nor tanks intended for use in chemical and petrochemical plants.
1.6 This Standard does not cover corrosion protection which may be required by local, state or federal authorities. Corrosion protection systems installed at the factory on carbon steel underground storage tanks are covered in the Standard for External Corrosion Protection System for Steel Underground Storage Tanks, UL 1746.