After verifying that all alarms are functioning (rapid clicking of the VIBRALERT Alarm, slow deliberate single bell strikes of the Bell Alarm, and, if installed, flashes of red light for the Beacon Alarm) open the purge valve slightly to vent the remaining residual air pressure from the system. All alarm shall cease operation when the system pressure drops to zero. When air flow stops completely, return purge valve to the fully closed position (pointer on knob upward).