(A) Each connection to an aboveground tank storing flammable liquids located below normal liquid level shall be provided with an internal or external control valve located as close as practicable to the shell of the tank.
(B) Except for flammable liquids whose chemical characteristics are incompatible with steel, such valves, when external, and their connections to the tank shall be of steel.
('81 Code, § 5.40.200) Penalty, see Ch. 13