Those with cockpit on/off for factory O2, tip or not ?

[Tony Armour]

Possible tip if you aren't aware. Not sure what other Mooney's are like my bravo in regards to the on/off handle and the bottle valve.

In my ignorance and I guess because I have done lots of plumbing in my life: I thought I was always working a ball valve. The spongy feeling of the on/off when turning off I now understand is due to the cable  length  etc. I would crank it, then again and then again. What we are operating is a solid cable inside a sheathing just like a lawn mower uses for the throttle or choke.

Now that I have broken my cable at the handle end and have had a chance to play with it, it seems like the bottle valve does not need to move much and it's either off or on....no in between. Someone else can chime in too but it almost seems as the pressure helps it open/close when it gets to a certain point. No need to crank the handle, just a smooth turn and gentle pressure until it stops.

Here is a picture of a Bravo, the gauge is next to the arm rest and then the black valve handle is to the right of that. 

Edited September 22, 2015 by Tony Armour

[kortopates]

Its takes about 2/3 revolution of the knob on the console to move the cable an inch or two at the regulator valve. Its more than a just a little. The hard part of the adjustment is to ensure the regulator valve arm is fully in the off position or it will leak out continuously. You may have to replace the cable to fix it properly - not sure.. Even though you have some left over length at the regulator end, I'll bet the cable is bent where it attaches to the regulator now and will not work effectively if you try to re-attach it further down past the bend as it may bind at the bent point.

But I wasn't sure what your question really was.

Edited September 22, 2015 by kortopates

[Tony Armour]

Actually it was a tip of what not to do. On mine, it's about 1/3 of a turn. It broke at the handle. On the handle mechanism there is a metal dowel and the cable makes a couple loops around the dowel. Mine now has one loop.

The valve arm itself moves very little and you can hear gas venting when opening and to a lesser degree when closing. That leads me to think the pressure is helping the valve (internally)

For sure its not "just" a ball type valve. 

There are a LOT more teeth on that big gear than it actually uses. Maybe the same is used on another model but with a bigger swing.

Edited September 22, 2015 by Tony Armour

[carusoam]

Starting to sound like the Apollo 13 movie...

'just gas venting overboard..'

Best regards,

-a-

[Robert C.]

Thank you! Very helpful. I've been wondering about that "mushy" feel and now I'll stop worrying about it and won't try to force it any more.

[Tony Armour]

Thank you! Very helpful. I've been wondering about that "mushy" feel and now I'll stop worrying about it and won't try to force it any more.

Robert, take a few minutes and pull the access panel on the pilots side and let someone operate the handle while you watch the movement at the valve. I wish I had seen it before. 

[Tony Armour]

Starting to sound like the Apollo 13 movie...

'just gas venting overboard..'

Best regards,

-a-

I think I'll oil it up to check for bubbles and inspect it with my lighter :-)

 

[carusoam]

We are going to need to dig a little deeper on what valve is back there and how it operates.

I think what you may be hearing is the first stage of a two stage regulator.

It would be somewhat unusual to vent O2 externally unless it really had to.  If it decided to leak on it's own things like grease on the jack screw would be susceptible to a high rate of exothermic oxidation.

A ball valve could open and close too much, too quickly for the high pressure low viscosity application.

I would expect a valve similar to a Scuba tank.  It allows air to bleed in slowly at first as the valve begins to open.

I'll try to find some data on Mooney installed O2 systems for Long Bodies. It will be interesting to know more details...

Best regards,

-a-

Edited September 23, 2015 by carusoam

[kortopates]

I wrote about O2 system leaks in another thread. But basically two kinds of leaks: High pressure leaks through the line and needle valves up connecting the portal to the tank and gauge up by the pilot and low pressure leaks through the regulator. Almost always a regulator leak goes through the line just as if you are unable to turn it off fully. The regulator is two stage. The first stage of the regulator lowers pressure down from a couple thousand psi to the teens, the second stage on the regulator is an altitude compensating regulator.