Abstract: A fire protection apparatus, particularly for liquid fuel containers which are carried in aircraft or other vehicles, comprises a pressure transducer for producing an electrical output upon sensing a pressure change of predetermined magnitude in a liquid, a source of fire extinguishant, an actuator for discharging the fire extinguishant from the source of fire extinguishant, and a self-energized repeater adapted to respond to the output of the pressure transducer and to generate a signal for operating the actuator to discharge fire extinguishant from the source.