These requirements cover external corrosion protection systems on steel non-pressure tanks that are used for the underground storage of flammable liquids and combustible liquids. The requirements are as follows:

A Part 1 covers external corrosion protection using sacrificial anodes, electrical isolation and thin film dielectric coating (cathodic protected tank);
B Part 2 covers external corrosion protection using dielectric fibre reinforced plastics or resins that are bonded to the tank (composite tank);
C Part 3 covers external corrosion protection and secondary containment using dielectric jackets (jacketed tanks); and

NOTE: Jacketed tanks as described in this Standard are also considered to be double walled.

D Part 4 covers external corrosion protection using polyurethane (coated tanks).
These external corrosion protection systems are intended to be installed, operated and maintained in accordance with the manufacturer's instructions.
These requirements cover external corrosion protection systems for steel tanks manufactured in accordance with the applicable requirements of ULC-S603, Standard for Steel Underground Tanks for Flammable and Combustible Liquids, which are used for the underground storage of flammable liquids and combustible liquids that are compatible with the materials of construction.