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Anchoring O2 in Front Baggage Compartment

mlwynn

Well Known Member
Hi all,

Since I expect to do a fair amount of cross country here in the West where mountains are high, wanted to have a removeable O2 bottle mounted in the front luggage compartment. I bought a bottle from Mountain High, which came with a nice mounting kit.

I have been looking at the floor of the luggage compartment and scratching my head about the best way to mount the bottle. The floor is pretty thin aluminium and secured forward on a right angle that is riveted to the firewall. The rear side of the baggage floor is secured to the aft wall but doesn't have any other support.

My options would seem to be:
1. Some sort of reinforcement of the floor where the bottle mounts would be, like a backing plate.
2. A strap or bar with the mounting lugs fixed to it and screwed to the forward and aft mounting holes for the floor
3. Replace the floor with a heavier gauge aluminium build it specifically to mount the bottle.

I looked through the archives and couldn't find much about baggage tie downs in the front compartment or anything about how the O2 bottle was secured. I am sure I am not the first to do this. Anyone have any other ideas or experience?
 
I mounted mine in the rear baggage compartment and planned to turn on the pressure before flight. But I became uncomfortable with not being able to turn the O2 on and off. I still use the baggage compartment mounting for storing the bottle when not in use. But I now mount the bottle by the left footwell extending back to the passenger seat when I am using it. Obviously can't fly with a passenger when O2 is on the floor next to me. But I feel safer being able to turn it off. When you open the valve in the baggage compartment and run a tube to you, that tube will pressure up to the bottle pressure, 2000 plus PSI.
 
Craig Taylor has a neat install in the forward baggage of his 8 and did a detailed description with pictures. He has a shutoff for the bottle in the cockpit. Try the search function.
 
Arm rest location.

As said before, having access to the bottle and valve is needed as I have found in my portable system.
My mounting solution has worked well, for me...no space lost and as handy as possible. I don't bother removing the cradle when I remove the bottle, then it holds POH or camera or...
http://www.vansairforce.com/community/showthread.php?t=99040
30shpir.jpg
 
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I mounted mine in a similar location, but I made a holder out of fiberglass that mounts inside the top rail and has an angle that attaches to the lower rail.

I used sandpaper wrapped on the bottle to sand down a foam mold for the fiberglass. (Hint: Move the foam, not the bottle when sanding)

I'm a Dan Horton wannabe.

Don
 
When you open the valve in the baggage compartment and run a tube to you, that tube will pressure up to the bottle pressure, 2000 plus PSI.

That's only true if you have an unusual regulator setup. Most of the common portable GA oxygen systems have the regulator mounted to the bottle, and only very low pressure O2 is in those fish-tank tubes that go to the cannula or mask.

Military systems can be different, of course.

Paul
 
I respectfully disagree Paul. My system is an Aerox system with a main twist valve and needle valve on the bottle for fine tuning flow. If mounted in the baggage compartment, you must open the main valve, select a flow rate via the needle valve, and have free flowing O2 in the cockpit. But you can'change your flow rate for changes in altitude. It is whatever flow rate you set it at in the baggage compartment before you took off. The alternative is to use the combined float ball flow rate indicator with a 3rd valve to control flow rate in the cockpit. The pressure between the bottle mounted needle valve and flow rate indicator vavle will reach bottle presure if the first two valves are open and the 3rd closed. There is no SCUBA type regulator to control pressure. The best solution for remote mounted bottle is a 90 degree turn primary valve the can be controlled with a push/ pull setup to open and close which Aerox also sells.
 
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Your Aerovox could be different Brad, but we have two of their systems - one with the little flow control valves on the bottle-mounted regulator, and one with flow control valves built in to the flow-meters near the cannulas. The regulators that mount on the bottles appear identical - the only difference is the location of the flow control valve - and when you turn the bottle on with the meter-mountd control valves, the intermediate line does nto pressurize to 2,000 - of that I am quite certain becaue there is no way those tubes coudl take that pressure.

You do, however, raise a very important point for anyone considering mounting the bottle in the forward baggage compartment - you need a way to control the flow back in the cockpit (like the meter-mounted valves). We bought that system for our -3 so that we could put the bottle in the baggage compartment and control the flow in the seat. I don't know how you'd really use the original system with bottle-mounted flow controls in a remote mounting configuration.
 
I respectfully disagree Paul. My system is an Aerox system with a main twist valve and needle valve on the bottle for fine tuning flow. If mounted in the baggage compartment, you must open the main valve, select a flow rate via the needle valve, and have free flowing O2 in the cockpit. But you can'change your flow rate for changes in altitude. It is whatever flow rate you set it at in the baggage compartment before you took off. The alternative is to use the combined float ball flow rate indicator with a 3rd valve to control flow rate in the cockpit. The pressure between the bottle mounted needle valve and flow rate indicator vavle will reach bottle presure if the first two valves are open and the 3rd closed. There is no SCUBA type regulator to control pressure. The best solution for remote mounted bottle is a 90 degree turn primary valve the can be controlled with a push/ pull setup to open and close which Aerox also sells.

That sounds like a bad idea.... I would mount that bottle where i can see the gauges and reach the valve.
 
I have a mountain high bottle mounted in my front baggage. If I am going high I turn it on before I leave the ground. Works extremely well with O2D2 in the cockpit. 17500 tailwinds are a thing of beauty.

I can turn the tank off and weeks later when I remove the tank the lines are still pressurized. Impressively air tight.
 
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I've been hoping someone might come up with a DIY remote valve control at a DIY price level. I'd love to mount my bottle in the rear baggage compartment. My cannulas have flow control on them. I just want to remotely turn the bottle regulator on and off for low pressure feeding into the passenger compartment.

I've thought about doing that with my two place regulator to Mountain High check valves, but was just not sure the bottle would not leak down over time with the valve left on.

Don
 
Needle valves control the amount of O2 flow, not the pressure of the O2, regardless of whether located on the bottle mounted regulator or the twist valve on the flow meter. There is no SCUBA type pressure regulation. That is why I chose not to live with the remote mount bottle.

There is a thread here somewhere that describes a homemade reel attached to the bottle mounted regulator so the remote mounted bottle can be turned off from the cockpit. The Aerox bottle ordered with the 90 degree on/off valve still appears to me the best solution for remote mount that can be controlled from the cockpit.

In the soaring world, some run copper lines from their remote mount bottle to a high presure connection on the instrument panel and plug in with a needle valve at the panel. There are several soaring suppliers that can provide what is needed for this type of setup.
 
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Needle valves control the amount of O2 flow, not the pressure of the O2, regardless of whether located on the bottle mounted regulator or the twist valve on the flow meter. There is no SCUBA type pressure regulation. That is why I chose not to live with the remote mount bottle.

Actually Brad, there is a pressure regulator in the part of the assembly (in the portable Aerox units) that screws on to the bottle - it reduces the pressure down to 25-30 psi. The needle valves at the bottle, or the valve on the flow-meter (Aerox calls it a Glo-Meter because it glows in the dark) control the flow rate, as you state...but they are dealing with low-pressure O2 at that point.

The reg that screws on to the bottle is analogous to the first-stage of a SCUBA regulator (which reduces pressure from bottle pressure down to 70-100 psi). You are correct that there is no "second stage" demand/pressure reg as in a SCUBA at the user end of the hose - just the bleed valves. But those clear plastic hoses will never see high pressures.

I verified this with Aerox on the phone this morning, just to make sure.
 
Ok Paul, good to know that it is regulated down to 25-30 psi at the needle valve. I feel better about the output not being at full tank pressure when the regulator is on. A little more forethought on my part and I would have ordered the tank with the remote push/pull control on the regulator.
 
O2 bottle mount

Michael,

Search keyword "oxygen" and poster "gear1" and you will see how I mounted mine in the baggage compartment. I set the mounting cradles adjacent to the baggage floor stiffeners so that no additional stiffeners were needed. Hopefully this will help.
 
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