FRESH AIR PORT MECHANISM FOR FACEPIECE USED ON SELF-CONTAINED OPEN-CIRCUIT COMPRESSED AIR BREATHING APPARATUS

摘要

Embodiment relates generally to method, system and equipment, the SCBA (100) that opening and closing one or more ports (1402) allows the pressure storage type respirator (SCBA) (100) of wearer to breathe to introducing fresh air port assembly (300) to mask (102) of surrounding air can make user's breathing surrounding air be not required when purification air, and can permit user and rapidly switch to purification air. When needed, a kind of fresh air port assembly (300) can be used for disconnecting and/or disables demand valves (104) in the SCBA (100) of demand valves (104) and mask (102), to allow surrounding air to enter mask (102), and the cover (102) of control outlet valve (202), therefore user can easily breathe surrounding air