Mooney M20K 231 Oxygen System Question

[FAST FLIGHT OPTIONS LLC]

Does anyone know why my nelson flow meters would only read up to the 10K foot mark when I have the knob turned to the wide open (no airflow restriction) on the ground utilizing my cannula system?  Just wondering if the Mooney "system" restricts the total amount of airflow on the ground or at lower altitudes or something like that. I would think I should be able to get the little ball up to the 15-18K foot mark on the indicator while on the ground or at any altitute for that matter? Since I cant , I'm wondering if the system is leaking somewhere and not producing full pressure?   I would like to figure this out before taking the plane to any significant altitude and "testing" it their for obvious reasons. I'm sort of new to flying with the whole fixed 02 system.

 

Thanks

[jlunseth]

I have the same plane, and have read that it does have an altitude compensated metering valve.  What I read was that it does not supply O2 at all until around 8k, and then meters the flow with altitude.  Don't remember where I read it though, the POH?

[FAST FLIGHT OPTIONS LLC]

That makes me wonder about it even more, since my system will produce the O2 on the ground.

[Awful_Charlie]

I don't know which kit you have in your aircraft, but in my TLS it is the 895-08015 from here: http://www.avoxsys.com/pdf/products/cylinder-and-regulator-assemblies/895-series-composite-cylinder-and-regulator-assemblies.pdf

There is a small flow at ground level, which increases with altitude

Ben

[IFlyMooney]

In my 1979 231, I get very little oxygen flow on the ground.  Mine is supposed to be set at 6K feet.  Once at altitude, the flow increases to the altitude mark on the meter.  I have one that goes up to 25k feet, and can attest that it works up to 23K and shows full flow at that altitude.