Oxygen refill - Tank size and filler adaptor help

[RobertGary1]

Realistically you have to have two tanks. One provides the bulk of the fill but not to the pressure you really want. Than you use a bit out of the high tank to bring the pressure up. As the low tank runs low you have it filled and it becomes the high tank, only to be used to bring the pressure up after the bulk of the fill comes from the new low tank.

 

-Robert

[larryb]

Also resist the temptation to top off your airplane tank frequently just because you can. You get the most efficient transfer out of your low pressure tank if your airplane tank is close to empty. I made that mistake one time, the airplane tank had more pressure than my low pressure cascade tank and o2 started flowing in the wrong direction.

[M20F-1968]

I have a 4 tank cascade, 300 c foot bottles.  Could someone describe an ideal management technique for filling?  I'll post a picture when I can.

John Breda

[Bob_Belville]

2 hours ago, M20F-1968 said:

I have a 4 tank cascade, 300 c foot bottles.  

John Breda

Of course you do, John! 

[chrisk]

2 hours ago, M20F-1968 said:

I have a 4 tank cascade, 300 c foot bottles.  Could someone describe an ideal management technique for filling?  I'll post a picture when I can.

John Breda

I'll try to explain it, since my partner never quite got the hang of it.  Only one cylinder is open at a time on the cascade!

1. Connect to plane
2. Open valve for the lowest pressure cylinder in the cascade
3. Wait a while until the pressure equalizes.
4. Close the valve on the cylinder you opened in the cascade
5. Open the next highest pressure cylinder in the cascade.
6. Wait until the pressure equalizes
7. Turn off the valve for the active cylinder in the cascade.
8. For a two cylinder cascade, your done, disconnect the plane.  For a 4 stage cascade, repeat the process above two more times, then disconnect from the plane.

As others have said, avoid frequent top-offs, and your O2 will go further.  If you have enough O2 for your trip, wait until you get back to fill up.  If your not sure, fill with the low pressure until you are sure.  And if it is a long trip, just fill it up and don't worry about it, since replacing two cylinders in a cascade is going to cost a less than a single fillup at a FBO.

And speaking of getting O2 filled at an FBO.  It can be harder to find than you would think.  I recall one trip where I had to fly the passes in Colorado on the way home.  Usually I just fly over them, but that requires going above 14,000.  A long story, but I came out to the plane in the morning and discovered zero O2 pressure on the pre-flight.  And of course no O2 at the small FBO.

[chrisk]

 

Since I was just dealing with O2 this week, here are some details.   It turns out I am getting 337 cubic foot "T" cylinders.  And they are quite heavy.  Each one is listed at 172lbs when full, and certainly harder to lift than my wife.     Price wise, a tank swap is pretty reasonable.

I keep my set up on a welding cart. I move it to the plane, and attach it as shown.  When the cylinders are fresh, I keep an eye on the gauge in the plane to prevent an over fill.  I also store the connector wrapped in a freezer bag to keep it clean.  (And yes, that is a hair band I stole from my daughter).  The the cart sits on the back corner of my hangar, where it should not fall.

 

[M20F-1968]

9 hours ago, Bob_Belville said:

Of course you do, John! 

It really was a no brainer.  It cost the same to ship two used cylinders from OH to MA as it did 4 cylinders.  Shipping was close to $200, the cylinders were $100 each.

300 cubic foot cylinders,  $20 each to fill.  Bought the gauges, hoses, etc. on line at a welder's supply outlet.  No rental.  No brainer.

I have only needed to use one cylinder so far.  Onboard tank is 50 cubic feet.  

John

[Bob_Belville]

3 hours ago, M20F-1968 said:

It really was a no brainer.  It cost the same to ship two used cylinders from OH to MA as it did 4 cylinders.  Shipping was close to $200, the cylinders were $100 each.

300 cubic foot cylinders,  $20 each to fill.  Bought the gauges, hoses, etc. on line at a welder's supply outlet.  No rental.  No brainer.

I have only needed to use one cylinder so far.  Onboard tank is 50 cubic feet.  

John

My system, I do not have a turbo so do not use O2 that often, is a 24 cu ft SkyOx and 2 150 cu ft tanks which I own and exchange at Airgas as needed.

After the initial cost - buying the equipment - O2 costs me maybe $20 per year including filling someone else's tank now and then. 

[rbp]

On 11/16/2019 at 7:27 PM, M20F-1968 said:

It really was a no brainer.  It cost the same to ship two used cylinders from OH to MA as it did 4 cylinders.  Shipping was close to $200, the cylinders were $100 each.

300 cubic foot cylinders,  $20 each to fill.  Bought the gauges, hoses, etc. on line at a welder's supply outlet.  No rental.  No brainer.

I have only needed to use one cylinder so far.  Onboard tank is 50 cubic feet.  

John

 

do you just load them into your car and drive to the filling station?

[Pinecone]

On 11/14/2019 at 6:34 PM, Austintatious said:

I would love to install one of their systems with the in panel control unit... says it is for experimental only.  Stupid.

 

I agree.  Maybe they can get one approved under NORSEE.

What I have done with mine is put in on the glare shield to the left of the hump.  A couple of Velcro strips works fine.  I run the supply hose up and wrap a turn around the hand mike (I knew it was good for something).

With the built in O2 system, you need to get the setup with a regulator.  They sell a kit with the O2D2 and the regulator, plus a couple of cannulas (they use a different one) and a couple of masks.

[rbp]

Seems like if I'm trying to reduce the frequency of (on-board) O2 fills, it would be less hassle (although more expensive) to buy a Mountain High O2D2 than it would be to source and buy/rent equipment to do  my own fills.

[DonMuncy]

2 minutes ago, rbp said:

Seems like if I'm trying to reduce the frequency of (on-board) O2 fills, it would be less hassle (although more expensive) to buy a Mountain High O2D2 than it would be to source and buy/rent equipment to do  my own fills.

Have you run the calculations to see how much each of the choices changes the costs. I suspect the best deal will depend on how freuently you fly on O2 and the cost to have your system filled. The fill cost have vast differences in different locations.

To me, there is a great benefit to having the tanks in my hangar and I can fill my system at my liesure. Once a long time ago, it took several hours waiting around getting mine filled.

[rbp]

its not just the cash outlay, but also my time. I spent 3 hours yesterday investigating where to buy/rent bottles, where i can get then filled, how to manage them in my hangar, what kind of transportation and filling equipment I would need, etc., and I still didn't get all my questions answered. I could have been billing my client or playing X-plane instead.

[geoffb]

Time spent hanging around waiting for the shop to fill you is time better spent?

[smwash02]

I put a lot of time and thought into the various options.

I have an O2D2 attached to the onboard O2 system. I have to fly .5 round trip to get it filled and this uses 3 hours of my time. Given the other variables, the $35-45 he charges is negligible. The O2D2 "paid" for itself on the first fill since it lasts 3-4 times as long, but it's still quite time expensive to keep up for frequent use.

I looked into the large tanks, getting them delivered, a partnership, etc. I found it was more hassle than it was worth for the few times I "have" to be >12.5. I only have sedans and no reasonable way to lug around a 300cuft bottle. I wasn't able to find a good deal on bottles listed above, I probably didn't look hard enough.

I have medical bottles from my C days. The $20 swap while running other errands is a simple, but dislike the space used in the back.

My current plan is to pick up an Innogen G5 when it's time to do more high altitude flying and use the onboard as the failover. Reports here are they're good to FL180. I'd like FL220 and I'll see how it pans out for me, but even if I'm capped at FL180 that's generally sufficient for what I do.

Once the onboard bottle expires I'll most likely get the other regulator for the O2D2 that fits the medical bottle and use that as the failover and see how inconvenient the space use is. Or get a smaller bottle that can sit in the hat rack since it's just the failover.

[rbp]

52 minutes ago, geoffb said:

Time spent hanging around waiting for the shop to fill you is time better spent?

that can be done overnight or while stopping for lunch

[M20F-1968]

On 9/19/2022 at 10:12 AM, rbp said:

 

do you just load them into your car and drive to the filling station?

The welder's supply will pick them up.

John Breda

[Fly Boomer]

8 hours ago, M20F-1968 said:

The welder's supply will pick them up.

John Breda

Do they pick up at your hangar?  Some people go to elaborate lengths to conceal that the oxygen is being used for aviation, and that hangar pick-up would be a dead giveaway.

[carusoam]

On 9/20/2022 at 11:20 AM, smwash02 said:

I put a lot of time and thought into the various options.

I have an O2D2 attached to the onboard O2 system. I have to fly .5 round trip to get it filled and this uses 3 hours of my time. Given the other variables, the $35-45 he charges is negligible. The O2D2 "paid" for itself on the first fill since it lasts 3-4 times as long, but it's still quite time expensive to keep up for frequent use.

I looked into the large tanks, getting them delivered, a partnership, etc. I found it was more hassle than it was worth for the few times I "have" to be >12.5. I only have sedans and no reasonable way to lug around a 300cuft bottle. I wasn't able to find a good deal on bottles listed above, I probably didn't look hard enough.

I have medical bottles from my C days. The $20 swap while running other errands is a simple, but dislike the space used in the back.

My current plan is to pick up an Innogen G5 when it's time to do more high altitude flying and use the onboard as the failover. Reports here are they're good to FL180. I'd like FL220 and I'll see how it pans out for me, but even if I'm capped at FL180 that's generally sufficient for what I do.

Once the onboard bottle expires I'll most likely get the other regulator for the O2D2 that fits the medical bottle and use that as the failover and see how inconvenient the space use is. Or get a smaller bottle that can sit in the hat rack since it's just the failover.

This will make a great pirep…

Innogen has a great product… for being on the ground.

Then they expanded it for people traveling around in pressurized aircraft….

 

Getting a decent pirep from using one in the flight levels would be stellar…

Either way… they are kinda expensive if you need to buy one for each seat…

 

This is why a pirep from an MSer would be really helpful…

Best regards,

-a-

[Pinecone]

IIRC, an Imogen will supply two people.

[Tom 4536]

9 hours ago, carusoam said:

This will make a great pirep…

Innogen has a great product… for being on the ground.

Then they expanded it for people traveling around in pressurized aircraft….

 

Getting a decent pirep from using one in the flight levels would be stellar…

Either way… they are kinda expensive if you need to buy one for each seat…

 

This is why a pirep from an MSer would be really helpful…

Best regards,

-a-

 

[Tom 4536]

Here is my PIREP from May: 

I tried an Inogen One G5 oxygen generator up to 17,500FT and the blood oxygen level never dropped below 96%. This was confirmed by two pulse oximeters. The generator has 6 output settings and I had to increase the output as I climbed. The highest setting (6) was needed at 17,500. Inogen told me that the generator would not work above 10,000 but the unit did not display any error messages. 

The generator weighs 6.5 lbs with the small (5hr) battery, the 12 volt cigarette lighter plug and cable. It has a shoulder strap that allowed me to hang it off the copilot seat between the pilot and copilot seats next to my portable oxygen cylinder. 

The best price I found was $2350 w/small (6hr) battery, free shipping and no tax, from:   mymedicaloutlet.com

[Tom 4536]

4 hours ago, Pinecone said:

IIRC, an Imogen will supply two people.

How did you connect the second canula?

[Pinecone]

https://www.inogenaviator.com/products

 

[1980Mooney]

6 hours ago, Tom 4536 said:

Here is my PIREP from May: 

I tried an Inogen One G5 oxygen generator up to 17,500FT and the blood oxygen level never dropped below 96%. This was confirmed by two pulse oximeters. The generator has 6 output settings and I had to increase the output as I climbed. The highest setting (6) was needed at 17,500. Inogen told me that the generator would not work above 10,000 but the unit did not display any error messages. 

The generator weighs 6.5 lbs with the small (5hr) battery, the 12 volt cigarette lighter plug and cable. It has a shoulder strap that allowed me to hang it off the copilot seat between the pilot and copilot seats next to my portable oxygen cylinder. 

The best price I found was $2350 w/small (6hr) battery, free shipping and no tax, from:   mymedicaloutlet.com

I bought a used OxyGo NEXT (which is manufactured by Inogen and identical to the Inogen One G5) before Covid drove prices crazy.  Works great.