Air flasks on the Type IXC\'s had a total capacity of 6200 liters (219 cu. ft.) at 2920 p.s.i. This was sufficient air to evacuate all main ballast, fuel ballast and bow and stern buoyancy tanks once at a depth of 180 feet, or 5.65 times the free air volume of these tanks. Most of them are located in the superstructure, but six flasks which are part of the four banks are located in the maneuvering room and engine room.

The high pressure blow system manifolds, piping and valves supply air for blowing main and fuel tanks and bow and stern buoyancy tanks.

The low pressure air system maniflods and piping supply air to operate ballast tank vent valves, to blow , flood and drain torpedo tubes, to blow sea chests, to operate engine shaft couplings, to operate diving plane clutches, to raise and lower radio and radar antenna masts, to cool the gyro compass, to provide air impulse for marker buoys when released, to pneumatic tools and to the horn.

This Class of boat also had stern and bow buoyancy tanks for trim.

High pressure air was rated a 2920 p.s.i. and low pressure air was rated at 171 p.s.i. I hope this has helped you in some way.