DOC AIRBUS | AMM A320FOXYGEN DISTRIBUTION - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. System Description
The oxygen distribution system supplies emergency oxygen to each emergency oxygen container above the passenger seats, in the lavatories and at the cabin attendant stations.
The system is only pressurized in case of emergency.
Flexible hoses connect the emergency oxygen containers to the supply system.
Low-pressure oxygen from the oxygen regulators is supplied to the two main supply lines. One line is installed below the cabin floor along the left side of the aircraft. The other line is installed above the cabin ceiling.
Riser lines or fall lines are installed at approximately every 4 fuselage frames to connect the overhead stowage distribution-lines to the main supply lines.
The connections on the overhead stowage distribution-lines that connect the emergency oxygen containers are approximately 28 in. (0.7112 m) apart. The emergency oxygen containers for the lavatories and cabin attendant stations are connected:
Bleed/vent valve 7503WR and bleed/test port 7504WR2 let a sufficient equalization of pressure between the oxygen distribution system and the cabin pressure. This prevents the 'SYS ON' indicator light and 'OXY PAX ON' indicator to come on accidentally when the pressure regulator is defective.
When the emergency oxygen system operates, the unwanted air in the supply lines bleeds through bleed/vent valve 7503WR and bleed/test port 7504WR2. This is to make sure that the supply lines only contain oxygen when the system operates.
There are three test ports, which are installed:
The oxygen distribution system supplies emergency oxygen to each emergency oxygen container above the passenger seats, in the lavatories and at the cabin attendant stations.
The system is only pressurized in case of emergency.
Flexible hoses connect the emergency oxygen containers to the supply system.
Low-pressure oxygen from the oxygen regulators is supplied to the two main supply lines. One line is installed below the cabin floor along the left side of the aircraft. The other line is installed above the cabin ceiling.
Riser lines or fall lines are installed at approximately every 4 fuselage frames to connect the overhead stowage distribution-lines to the main supply lines.
The connections on the overhead stowage distribution-lines that connect the emergency oxygen containers are approximately 28 in. (0.7112 m) apart. The emergency oxygen containers for the lavatories and cabin attendant stations are connected:
- To the distribution lines of the overhead stowages
- Or to their own feeder lines.
Bleed/vent valve 7503WR and bleed/test port 7504WR2 let a sufficient equalization of pressure between the oxygen distribution system and the cabin pressure. This prevents the 'SYS ON' indicator light and 'OXY PAX ON' indicator to come on accidentally when the pressure regulator is defective.
When the emergency oxygen system operates, the unwanted air in the supply lines bleeds through bleed/vent valve 7503WR and bleed/test port 7504WR2. This is to make sure that the supply lines only contain oxygen when the system operates.
There are three test ports, which are installed:
- In the intermediate line
- In the oxygen distribution system downstream of the oxygen regulators
- In the oxygen distribution system downstream of the check valves.