Except as allowed under §154.1330, each cargo tank must have a high liquid level alarm system that:

(a) Is independent of the liquid level gauging system under §154.1305;

(b) Actuates quick-closing valves under §§154.530, 154.532, and 154,538 or a stop valve in the cargo tank loading line to prevent the tank from becoming 100 percent liquid full and without causing the pressure in the loading lines to exceed the design pressure; and

(c) Actuates an audible and visual alarm at the cargo control station at the liquid level at which the valves under paragraph (b) of this section are actuated or at some lower liquid level.