Transfill O2 Equipment

[aviatoreb]

What do I need as far as equipment to refill my O2 bottles in the hangar.

-And I understand that one rents large cylinders from a gas supply company?

-What should I expect that to cost?

-Is there a standard adaptor?

-How many cubic feet in one of those big cylinders?

[DonMuncy]

The number of cubic feet in the tank is not the important question. The real question is how many fills you can get before a refill. Unless you have some really expensive equipment, you can only fill a tank to the pressur level in your "filling" tank. Every time you use it that number drops. So the first time you fill your smaller tank, you may fill it 90%. The next time, depending on how low you ran it down to, you may only fill it 70%, etc.

On my built-in tank on my 231 (73 cu. ft.), with the levels I was willing to tolerate, could get about 3 fills before refilling my big tank. By using two tanks, and cascading, you can get some more, but you have the cost of another tank. If you are filling a portable tank, I don't know.

I suggest you plan on getting 3 fills, on a tank (at about $25 per tank; it varies), then price out the cost of a big tank (or call your local welding supply store about the rental cost), then calculate how many fills you will require per year. If these numbers make sense to you, contact me again and I will help you work out the transfill stuff, and I can give you a few tips.

[johnggreen]

Go to the Aerox website. The cascade filling system will be just under $500. You will need to rent two tanks, the cost will be minimal, maybe $60 per year. The refills about $35 each. With my ox saving cannulas, I probably get about 20-30 hours of oxygen for two people in my Bravo, probably more. The cost is so minimal, I don't pay too much attention. Note that you be sure to get aviator oxygen, not medicinal oxygen. The aviator oxygen has less moisture.

Once you get used to using Oxygen, you get spoiled. I usually put it on over 8m in daytime and 6m at night. If I'm hard IFR, l'll go with 6m even in day. It makes a big difference in your alertness and a bigger one with night vision.

Jgreen

[DonMuncy]

John,

your information is dated. All O2 now comes from one source. Aviation O2, welding O2, etc. In the medical setting they use O2 with moisture, but they have to add it at the medical site. The only logical (economical) way is welding O2.

You need to clue me in on how to use it. With my Oxysavers, maintaining 94% O2 levels, I only get about 10 to 12 person hours from a 72 cu ft tank. How about everone else out there, How many hours do you get out of a tank.

[Riq]

How many hours do you get out of a tank.

I have a skyox 24cu.ft. system that lasts almost 23hrs(advertised) on a cannula, 8-10hrs on a mask. I usually get 16-18hrs with a cannula at 16-18000 to keep me around 96%.

My wife needs a lot more o2 than I to keep at the same level, therefore together we burn a lot more. Not sure how much more, havent quantified it yet. (quantifying wifes needs=scary business)

I also fill off my "welding" tank. It works great, saves time, and money. I let it get to 500lbs and that is when I have it filled for 35$.

[danb35]

You don't necessarily have to rent the large cylinders; you can buy them instead. Higher up-front cost that way, of course (I recall around $200 when I bought one), but then the only recurring cost is having it filled, which is done on an exchange basis ($15 or so).

[aviatoreb]

Thanks folks. I see the cascade filling system at Aerox - but there are many variations. Are the features important? Should I just get the one at the top of the list?

The 3 refills number seems to be cited for a big "built in" system number for one of those ~75cf bottles? I have 24cf carry bottles, so I presume I could refill several more times.

I am mostly interested in doing this for convenience rather than saving money, but as far as I can tell, this is a very low cost proposition at the end of the day so it should be quite worth it, and maybe even save some money. I live in a rural area, where to refill my bottle requires a 25 mi each way drive. But since I live in a university town, with a hospital also, the same business delivers bottles of all sorts of gases every day. So if I rented a big O2 bottle from them to transfill, that would make my life simpler.

[aviatoreb]

Go to the Aerox website. The cascade filling system will be just under $500. You will need to rent two tanks, the cost will be minimal, maybe $60 per year. The refills about $35 each. With my ox saving cannulas, I probably get about 20-30 hours of oxygen for two people in my Bravo, probably more. The cost is so minimal, I don't pay too much attention. Note that you be sure to get aviator oxygen, not medicinal oxygen. The aviator oxygen has less moisture.

Once you get used to using Oxygen, you get spoiled. I usually put it on over 8m in daytime and 6m at night. If I'm hard IFR, l'll go with 6m even in day. It makes a big difference in your alertness and a bigger one with night vision.

Jgreen

Hi John, Actually, I had an interesting conversation with the company manager last summer about the differences in medical versus aviation oxygen. He cited to me the exact moisture contents of each.

My understanding now is that aviation oxygen has only one standard of moisture content which is designed mostly with the high flying jets in mind. I forget the numbers but both are overwhelmingly mostly O2, but the tiny bit of O2 in medical O2 is removed from aviation O2 for a specific reason. The jets keep very large bottles in parts of the jet that may be exposed to the frigid cold temps at FL45 and so there is a real worry of the moisture in the lines freezing, preventing O2 flow if it is needed. This is a different need than at least for a bottle that is kept in the cabin behind the seat with the passengers in a four seater where hopefully temps don't reach -50F. In that case the minor moisture content of the medical o2 could do as designed, which would be less drying of mucous membranes/raspy voice, noise, etc. I ran one bottle of medical o2 last summer and it was nice. I am undecided if this is a good idea generally or not. Are we drying out our membranes for sake of an aviation standard designed for an entirely different kind of airplane than our relatively low flying GA planes.

[Riq]

My local fbo charges 42$ to refill, no matter the size.

I purchased my o2 tank about 10yrs ago for roughly $300 and the adpt hose from sportys for $55. I exchanged it a couple weeks ago for $35. I think its ~120cf. Definitely more convenient, and cost effective.

Note-If any bigbuck guys wanna argue that having the fbo fill it on a phone call and their time value etc, is more convenient and cost effective for them, should send some cabbage my way.

The only semi-drawback is having to take it back and forth from plane to home. But, the bonus is that after too much eggnog, you can strap on the o2 in the morning.......

[danb35]

Hi John, Actually, I had an interesting conversation with the company manager last summer about the differences in medical versus aviation oxygen. He cited to me the exact moisture contents of each.

The specs may be different, but they both (along with welding O2) come out of a liquid oxygen tank. There's no moisture in there. And welding these days is at least as demanding for purity as medicine or aviation.

[fantom]

At what level on a 24cf bottle is it reasonable to refill?

Oh, and I've been using medical O2 for two decades with no ill effects....I hope!

[Riq]

Thats dependant on your individual usage.

Im my 24cf I still have ~3-4 hours with 500lbs, and find myself refilling at that point. If the family were in there for our NY xc trips, I make sure its on the full side.

[fantom]

Thats dependant on your individual usage.

Im my 24cf I still have ~3-4 hours with 500lbs, and find myself refilling at that point.

Copy that.....I'm usually around 700 lbs when I plan on filling up. That's about 5-6 hours.

[David Mazer]

Every time I've done the math, it never makes sense to buy all the equipment. I just get to fly the plane to nearby Daytona where it costs $40 to fill the O2 once in a while.

[larryb]

I have 2 125cuft tanks and a cascade transfill rig. I only have a 15 cf portable bottle. It will take several years to recover the cost, but the convenience is why I bought it. I refill after every trip that I use o2, often at around 1000 psi. It is very convenient to fill the 02 at home. With the hassle of filling at the local shop I probably would use it less often.

[N201MKTurbo]

I have a Haskel gas booster I bought on EBAY for $300.00 that looked brand new (they are $6000 new) .

With it I can fill my portable cylinders to 2000 pounds, well 2300 for one and 2100 for the other, with my supply cylinder as low as 400 PSI

I own my own supply cylinder and don't trade it out. I take it to the gas place and have them fill it from the manifold. The same pipe as the Aviators breathing oxygen comes out of.

The guys tell me that some times their cascade can get contanimated when a trade in bottle that is accidentally backfilled with another gas. If you trade in your bottle it is most likely filled from their cascade.

I asked the foreman at the gas works what the difference was between Aviators breathing oxygen and any other oxygen that they have. He said that the only difference is that the ABO gets tested. I asked if it has ever failed the test. He said not in 35 years.

[aviatoreb]

Every time I've done the math, it never makes sense to buy all the equipment. I just get to fly the plane to nearby Daytona where it costs $40 to fill the O2 once in a while.

I think you messed up the money math when you bought an airplane. We all did! :-) No wait - you two, don't you?!

[David Mazer]

1.5 right now but 2 in a few months. I suppose you are correct but it makes me feel better to save $20 even though I have spent hundreds of thousands already. I didn't say it made any sense.

[DrBill]

I get my gas from Airgas, here's their website oxygen list. .338/cu ft. The valve on the tank is CGA 540. You need an adapter from CGA 540 to the fill port on your bottle. (Mine was Puritan Bennet). Got the hose adapter from Aircraft Spruce for $55.

I have a 22cuft portable cylinder so I plan on 6-8 refils from the 251 cu ft tank. I only have one tank (use it for welding too) so th e pressure gets less and less each refill. I got 5 person hours on regular canual last triip so I bought the oximizer canula and will try that next long trip. Hope to double the life.

When I first had the tank filled at the local airport, they used 3 tanks in succession. to get the pressure up to c 1200-1500 (I forget) PSI. I use my welding tank and got it to 1200 and will get the tank refilled below 1000 psi.

Call your local Airgas distributor for price on rental and purchas of O2 tanks of various sizes.. I used a 90cf tank for years for welding alone.

BILL

Oxygen, Industrial Item # Description Cyl Size Volume UOM Minimum Purity Typical Purity Pressure CGA Price

Add

OX300

OXYGEN IND 337 CF 337 337 CF 99.5% 99.6% 2640 540

$0.3386

Add

OX282

OXYGEN IND 282 CF 282 282 CF 99.5% 99.6% 2500 540

$0.3386

Add

OX200

OXYGEN IND 251 CF 251 251 CF 99.5% 99.6% 2220 540

$0.3386

Add

OX100

OXYGEN IND 125 CF 160 125 CF 99.5% 99.6% 2220 540

$0.3386

[aviatoreb]

1.5 right now but 2 in a few months. I suppose you are correct but it makes me feel better to save $20 even though I have spent hundreds of thousands already. I didn't say it made any sense.

Just making fun - my question about transfilling is one of convenience and remember my rural location.

So good - 1.5 > than the 1.2 of several months ago. Enjoy!

[M016576]

Once you get used to using Oxygen, you get spoiled. I usually put it on over 8m in daytime and 6m at night. If I'm hard IFR, l'll go with 6m even in day. It makes a big difference in your alertness and a bigger one with night vision.

Jgreen

6m might be a little excessive, but it depends on your own physiology. I live at 4500'. Growing up I lived at 6000'. I didn't see many people driving their cars on O2 to help with night vision!! ;-)

Now if you are acclimated to sea level and are a smoker, different story!

[David Mazer]

Just making fun - my question about transfilling is one of convenience and remember my rural location.

So good - 1.5 > than the 1.2 of several months ago. Enjoy!

Taken in fun. No worries.