Tip: Adapting a Roscoe Pediatric Medical Oxygen Regulator for 2 Place Aviation Use

Guy Prevost · #1 11-24-2011, 12:56 PM

Before we start, a few important notes.

1. You must clean all of these parts thoroughly with a water based, non flammable cleaner before attaching them to oxygen. The presence of any grease, lubricant, oil, etc can very easily start a fire. As soon as one of these easy to start items begin to burn, the metal (in the presence of pure oxygen) will start to burn too. This is not a fire you want in your cockpit!

2. If you do set yourself on fire using this info, it is not my fault. This is how I built mine. For all you know, I'm a complete moron.

OK. Disclaimers taken care of. I purchased a Roscoe Pediatric regulator and a couple of D sized Aluminum cylinders on Ebay. I looked long and hard for a medical regulator that had an NPT threaded output, but have not been able to find one. If someone does find one, please post the info!

The Roscoe has a hose barb output that attaches with a metric thread. I don't have a lathe, so I had to kludge my setup together. I removed the hose barb from the regulator and figured out what size metric thread it had.

I then bought a tap of the same size and a stainless steel metric bolt. I cut the end off of an NPT nipple and drilled and tapped the ID for the metric bolt.

I then cut the head off of the bolt and drilled a hole through the center. After a thorough cleaning, the bolt was threaded into the nipple with Teflon tape in order to make an adapter.

I used the rubber gasket that came with the barb fitting and attached the nipple to the regulator.

The last step was to add a T and a pair of oxygen safe dry break connectors from Mountain High.

I tested for leaks in a sink full of water.
I make it a point to always turn the bottle off for takeoff and landing. If the regulator and bottle are turned on, I like to always have at least one cannula attached as I don't want to risk a leak at the fittings. If a leak happens around a gasket it can create heat and that can lead to fire. Even though I don't have any leaks, the regulator was not designed to have a valve after it, so I keep a cannula attached if the gas is flowing.

Danny7 · #2 11-24-2011, 01:07 PM

how much did you pay for the different materials?

panhandler1956 · #3 11-24-2011, 01:31 PM

Guy,
Great tip! I'm putting this on my list of projects!

Thanks!

Bugsy · #4 11-24-2011, 02:31 PM

Looks great Guy

rocketbob · #5 11-24-2011, 03:41 PM

I have the same exact regulator, which I bought on eBay for around $25. Since I have a lathe I cut the barb off the fitting and drilled a hole for a 1/8" NPT thread into the fitting itself. There's enough meat left in the fitting to run a 1/8" bottoming pipe thread tap into it. I was able to thread one of the same CPC fittings I got directly from the manufacturer at a fraction of the cost MH sells them for.

Guy Prevost · #6 11-25-2011, 08:40 AM

Quote:

Originally Posted by Danny7

how much did you pay for the different materials?

I think I paid about $20 for a pair of new bottles. The regulator was about $25. I bought the cannulas and CPC fittings from Mountain High out of convenience, but I'm sure better deals could be had elsewhere. If I remember right, the cannulas and fittings nearly doubled the cost of the system.

I also bought a transfill system that will let me fill the medical bottles or aviation bottles from a welding cylinder.

humptybump · #7 11-25-2011, 09:53 AM

Guy, thanks for the tip and write-up. (same to you Bob).

For the RV-8(A), where do you fix the bottle so it is reachable in flight?

chaskuss · #8 11-25-2011, 03:38 PM

Quote:

Originally Posted by humptybump

Guy, thanks for the tip and write-up. (same to you Bob).

For the RV-8(A), where do you fix the bottle so it is reachable in flight?

Glen,
This is in the archives. See

http://www.vansairforce.com/communit...=oxygen+bottle

http://www.vansairforce.com/communit...=oxygen+bottle

humptybump · #9 11-25-2011, 04:05 PM

Thanks for the links. I read them a while back. The one thing I saw in the archives that was close to what I'm asking was a picture of a tank mounted horizontally on the back of the RV-8 pilot seat.

I'll have to test the theory. I'm not sure I'm flexible enough to open the valve once flying.

I was hoping Guy could explain his install since he was recommending "turning off the oxygen for take off and landing".

I'll install a dummy mock-up to the back of the seat and see if I can reach it.

Guy Prevost · #10 11-25-2011, 05:12 PM

Quote:

Originally Posted by humptybump

Guy, thanks for the tip and write-up. (same to you Bob).

For the RV-8(A), where do you fix the bottle so it is reachable in flight?

I hang mine front the crossbar behind the front seat when dual. When solo, I usually just set it in the passenger footwell. I really should secure it better for the latter case...