Thanks all for the tips provided. I am sure I can find some solution now. :-)
I ordered a dedicated transfer set for my airplane and for Dutch/Belgian oxygen bottles with a Dutch provider of gas solutions. They will assemble and test the kit. I am awaiting the shipment. I will report on the outcome.
PM me for details.
Thanks all for your tips.
Forum,
I am happy to update you on my oxygen-refill solution for my 1981 Piper Seneca III with built-in oxygen with a cascaded bottle set-up.
Main inspiration:
I designed a transfill hose from Belgium/Dutch oxygen bottles to the Scott connector on the side of the aircraft. This hose is equipped as follows:
O2bottle → [RI2 connector → manometer → valve → manometer → 1.5m flex → CGA540 → Scott 9/16] → Aircraft bottle
The last part (CGA540→Scott 9/16) I bought off this forum from wleferrand (thanks!). The first part I had assembled and tested at Eurint (www.eurint.com) in the Netherlands who gave me a very good service.
I rented two oxygen bottles from the local gas shop and bought a dolly.
This weekend I tested it as per Piper Service manual and it worked out great: topped my built-in bottle off to the specced 1800psi. And of course taking special care that no grease gets in contact with the oxygen and that the transfill goes slow enough to prevent heating up the receiving bottle too much. I also made a simple BAR<>PSI conversion table so I didn’t make stupid mistakes.
Let me know if you need more detailed info.
Thank you for all your tips and pointers.
WOW that is ultra impressive!
I like the engineering… the steel cable preventing the hose from getting pulled out of the swaged fittings.
Nice!
Niner_Mike wrote:
topped my built-in bottle off to the specced 1800psi
I assume you have the table in the POH for conversion of the pressure needed depending on the environmental conditions (i.e. outside temperature).
I tend to not top it up as I don’t have to take nothing into account. I just fill, say, to 1000psi and fly with that until refill needed. Using oxysaver cannulas this lasts for a lot more than I can sit. Of course for long flights with a full cabin I’d top it up.
The best thing about having your refill station is that you can easily decide on when and how much to fill. And having the bottle(s) next to the plane it’s a non-issue to refill whenever necessary.
@UdoR
Yes, the POH calls from 1850 psi @70°F but the table allows you to overfill to a higher pressure / higher temp so when it cools down it lands at 1850.
In reality I filled verrrry slowly to 125 bar indicating (1813 psi) and according to the gauge in the airplane, I landed at 1750 psi.
I also repurposed my MHOxygen O2D2 for extra range. So I have plenty of oxygen range, making me reasonably independent of out-of-base refills.
And I admit … it was a nice project too.
Thanks all for the tips provided. I am sure I can find some solution now. :-)
Eurint (www.eurint.com) can help you with your Dutch master bottle connector
I haven’t got around to buying an O2 system yet. Someone offered me the use of a BOC ‘F’ sized medical oxygen cylinder (1360 L) and regulator which weighs 17 kg. It would be convenient as I wouldn’t need to worry about refills etc. Would it be feasible to use this on board? I guess I would then just buy a flow meter and some cannulas if so.
17kg is really heavy. I would not carry that even if somebody gave it to me. For refilling, perhaps.
What is the regulator? Welding regs tend to go up to maybe 100psi. For use with a constant flow cannula, or feeding a demand regulator like the MH O2D2, you want about 20psi.
If you get a demand reg you can use a cylinder which is about 5x smaller; data here.
Quite simply, the best today, and for some years, is the MH “48 cu ft” composite cylinder, their 1st stage reg, an O2D2, and the cheap cannulas. Photo near the end of here.
We have 2 stage regulators that can be set to output 0-6 bar (~100 psi). MH stuff looks good of course but I would be travelling with 4 people and only need O2 maybe 4-5 trips a year so the cost of that gear is a bit off-putting for me.
Probably using big cylinders is best but I do have a bit of a fear of setting the place on fire, or buying a cylinder with some weird fitting for which I wouldn’t be able to make up a transfilling hose easily.
