These requirements cover preengineered corrosion protection systems. Part i covers factory-installed galvanic-type cathodic protection. Part ii covers factory assembled composite systems. Part iii covers factory assembled jacket systems. Part iv covers factory assembled coated systems. These corrosion protection systems are intended to be completely installed at the factory on carbon steel underground storage tanks. Part ii of this standard covers fiberglass reinforced plastic (FRP), materials only. Part iii of this standard covers FRP, polyurethane, polyurea and high density polyethylene (HDPE) materials only. Part iv covers polyurethane materials only. These corrosion protection systems are intended to be installed, operated and maintained in accordance with the manufacturer's instructions.