Boeing Crew Oxygen systems with two bottles

[Tom Sawyer]

B787 - two cylinders supply what is effectively one system for the Flight Deck. There are 3 fuses (the ~ in a box) to prevent loss of all pressure due to leak in flight deck pipe circuit on one side branch. However.........






It is possible I guess that if a fracture were to occur in the pipework between either cyclinder head shut off valve and 3 way distribution manifold, it could be a problem! I'm guessing that there could be Non Return Valve at each point where the supply from the cyclinder connects to the distribution manifold to prevent flow from one cylinder to the other, and the regulator assembly on the cylinder head can detect excess flow and close off ?
My tech notes don't give any further info. I'll have a look in the AMM later if I get a chance.

If a PX Transducer fails, I think the display will go blank with a status message for you guys and associated fault code for us Engineering types.