Cockpit Oxygen Supply
 

Can anybody give some data regarding OXYGEN LOSS
while opening and closing the oxygen bottle few times each day,
on a crew change ?

Would it be better to keep it open,
or close it when leaving cockpit ( usually so, per checklist) ?

:(:}:ugh::rolleyes::yuk::{

What sort of aircraft? Portable O2? Fixed O2?

Why would you lose oxygen by opening and closing a bottle? Surely only mask use (test and emergency) and leaks would deplete the supply.

Well it does not depend on aircraft. ...So it can be any aircraft. And no...I did not mean the portable O2.

While opening the bottle there is a sound of gas filling the part of system. While closing it that part of the pressure may be lost in next few hours. Maybe not.

it doesn't matter really because you try (or should try) if there's O2 flow from the mask.

Us (the nice maintenance guys) will change the bottle if pressure gets to low....