Oxygen Refills- Robbed

[MikeOH]

Good grief!

I've only continued to follow this thread out of sheer morbid curiosity!

SIX pages about O2 and still going strong...it's beginning to feel like hot AIR

[DonMuncy]

54 minutes ago, N201MKTurbo said:

I know my tank is clean and has never had anything but clean oxygen in it. Probably not necessary, but I thought it was prudent.

That is interesting. It never occurred to me that any contaminants might have been introduced into the tanks at the welding shops that would not have been removed by emptying the tanks before refilling. 

[N201MKTurbo]

9 minutes ago, DonMuncy said:

That is interesting. It never occurred to me that any contaminants might have been introduced into the tanks at the welding shops that would not have been removed by emptying the tanks before refilling. 

They don’t always empty the welding tanks. They crack the valves open and smell it. If it smells like acetylene they will vacuum out the tank. Apparently, if you run an oxygen tank dry it can back fill with acetylene when using a torch.

[PeteMc]

3 hours ago, MikeOH said:

Good grief!

I've only continued to follow this thread out of sheer morbid curiosity!

SIX pages about O2 and still going strong...it's beginning to feel like hot AIR

Ummm....  Did you miss that this was a pilots group?!?!?!?!?!?!?!?

OF COURSE it's going to get drawn out as far as possible!  And then some !!!  

[A64Pilot]

On 7/12/2023 at 7:52 PM, DonMuncy said:

That is interesting. It never occurred to me that any contaminants might have been introduced into the tanks at the welding shops that would not have been removed by emptying the tanks before refilling. 

I’ve never seen a tank emptied to be filled, and I’ve never seen one smelled for acetylene.

Only way that could happen is in the torch, which could happen if the regulator could allow back flow, which unless it’s broken it can’t, and if it broken in a way that could allow back flow then it wouldn’t regulate.

The idea of acetylene in an O2 bottle is terrifying, the explosion would be catastrophic, I’m talking HUGE bomb. I think, am almost certain that Acetylene under pressure may go off just from pressure.

I had never thought about acetylene getting into an O2 bottle, surely that never happens or we would have read about the deaths?

I’m 99% sure Acetylene is stored in a tank filled with balsa wood and soaked with Acetone because the gas under pressure would explode, that’s what I was told anyway just as I was told to never lay the bottle down, maybe old wives tales, but in the oil field we treated Acetylene bottles like pet snakes. I had backflow preventers on my torch to keep the gas out of the lines but never consider the bottle https://osha.oregon.gov/OSHARules/interps/valve.pdf

Years ago as an oilfield welder we would take a rose bud adjusted neutral and fill an open piece of drill pipe with O2 and Acetylene mix and standing aside ignite it, even in a completely open section of pipe with zero restriction, the explosion had to be heard to be believed.

I’ve dumped plenty of SCUBA tanks to change mixes, it’s noisy, takes longer than you would think and the valve gets extraordinarily cold. Good shops have a muffler they put on the tank or the noise would drive you out of the shop. I can’t imagine doing that with O2, the fire hazard of a nearly pure O2 environment would be insane. Think Apollo 1.

I would hope that if Acetylene contamination was possible that they would test for that just Like I used to test for O2 and Helium and later CO after some cave divers died in Mexico because the wrong compressor oil was used in the compressor.

[A64Pilot]

On 7/12/2023 at 11:07 PM, M20Doc said:

It’s the resurrection of the CB club.  Mooney guys looking for a a way to a few pennies.  

It can be more than that. My local Airgas place, the only source for O2 absolutely refused to fill my tank without a prescription, as they said it was illegal and then when I got the prescription refused to fill any tank without a medical valve for breathing purposes stating liability.

”medical grade” oxygen which I think we have established isn’t a thing but it’s classified as a drug by the FDA so Airgas would be selling me a drug without a prescription

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9575339/#:~:text=Medical grade oxygen is classified,saturation while breathing atmospheric air.

Local FBO did have a cascade of I believe 6 welding tank bottles and would fill the bottle for $50 but you had to leave it and come back the next day. They obviously didn’t want to fill little portable bottles but would I guess service aircraft, but as this was South Georgia not many had any real need for O2.

I had a need to fill the bottle multiple times as I was doing engine performance testing up to FL250 so I got a hose and filled it from welding tanks we had at the plant, didn’t have any other choice really. 

Edited July 15, 2023 by A64Pilot

[1980Mooney]

14 minutes ago, A64Pilot said:

It can be more than that. My local Airgas place, the only source for O2 absolutely refused to fill my tank without a prescription, as they said it was illegal and then when I got the prescription refused to fill any tank without a medical valve for breathing purposes stating liability.

”medical grade” oxygen which I think we have established isn’t a thing but it’s classified as a drug by the FDA so Airgas would be selling me a drug without a prescription

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9575339/#:~:text=Medical grade oxygen is classified,saturation while breathing atmospheric air.

Local FBO did have a cascade of I believe 6 welding tank bottles and would fill the bottle for $50 but you had to leave it and come back the next day. They obviously didn’t want to fill little portable bottles but would I guess service aircraft, but as this was South Georgia not many had any real need for O2.

I had a need to fill the bottle multiple times as I was doing engine performance testing up to FL250 so I got a hose and filled it from welding tanks we had at the plant, didn’t have any other choice really. 

You are in Florida.  Why don't you just go to a dive shop?  Those here have high pressure pumps that can fill my portable tank while I wait - not waiting overnight.  They just wanted to see my pilot's license.  

[A64Pilot]

1 hour ago, 1980Mooney said:

You are in Florida.  Why don't you just go to a dive shop?  Those here have high pressure pumps that can fill my portable tank while I wait - not waiting overnight.  They just wanted to see my pilot's license.  

I was in Albany Ga then.

Dive tanks don’t use a CGA 540 valve like our bottles do, so unless someone has an adapter they can’t fill you either, and most would want something stupid like a VIP, and you don’t take one of our valves out as easily as you do a SCUBA valve.

Any tech diving is done with the European DIN valve.

I’m in or near Cave Country so I know most of the dive shop owners so I’m sure I could work something out if I had to, but honestly all you need to fill your own is a simple hose, you don’t need gauges or anything, both tanks use the same valve

 But for me it’s all irrelevant as I’ve been retired for 6 years or so and unless someone has a heart attack or something my O2 system will continue to gather dust in the wall locker because I don’t fly that high anymore, maybe one day I may visit where it’s needed but it’s not around here.

If I were to start using O2 for some reason I’d get a couple of tanks and fill my own and if I was really hard core I’d get a Haskell compressor, tech divers salavate over Haskell’s, particularly for Helium as ultra pure Helium ain’t cheap.

[PeteMc]

Follow up on O2 and is there a difference.  I posted a link to a video by Dr Brent Blue on O2 and CO that is always relevant, but maybe a little more so going into winter where we crank up the heat and close down those cold fresh air vents.

In the video Brent does discuss a little bit about how all the O2 is now the same.

https://www.youtube.com/watch?v=pOEBoeuyR0U 

[cliffy]

Real good review  Thanks!

[PT20J]

I got mine filled at a local dive shop. They had the correct fittings. Didn't ask for anything except a credit card. They wanted a couple of hours because the tank gets hot if filled too quickly.

[Mac80]

Novice question about cascade oxygen tanks. 
 

When you decide to take an oxygen line tank off line, say you have 2 tank connections or more, and you remove  the low tank to be filled later there appears to be no inline valve separating the two tanks. So do you need to disconnect the 2 tank system and replace it with  single tank trans filler , just not use it until the empty cylinder comes back, or just have extra cylinder and valve so you can continue to use the remaining source tank until the low cylinder is filled?

 

 

[N201MKTurbo]

15 minutes ago, Mac80 said:

Novice question about cascade oxygen tanks. 
 

When you decide to take an oxygen line tank off line, say you have 2 tank connections or more, and you remove  the low tank to be filled later there appears to be no inline valve separating the two tanks. So do you need to disconnect the 2 tank system and replace it with  single tank trans filler , just not use it until the empty cylinder comes back, or just have extra cylinder and valve so you can continue to use the remaining source tank until the low cylinder is filled?

 

 

I think you understand the issue. I would just wait till you got your tank back. Without seeing your setup, it is hard to comment, but if you needed to use it, you could probably get a plug for some fitting in your system. Just take the manifold to your local welding shop and ask them. They usually have a good selection of high pressure fittings.

[A64Pilot]

1 hour ago, Mac80 said:

Novice question about cascade oxygen tanks. 
 

When you decide to take an oxygen line tank off line, say you have 2 tank connections or more, and you remove  the low tank to be filled later there appears to be no inline valve separating the two tanks. So do you need to disconnect the 2 tank system and replace it with  single tank trans filler , just not use it until the empty cylinder comes back, or just have extra cylinder and valve so you can continue to use the remaining source tank until the low cylinder is filled?

 

 

A “real” cascade does connect multiple tanks to one manifold with enough valves to isolate each tank, so all you do is wait until pressure equalizes, then close that tank, open the next tank etc.

However a DIY only needs a couple of tanks, connect to the low pressure tank, open valves slowly until pressure equalizes, then close both valves, remove hose from the big tank, connect it to the higher pressure tank, repeat.

It’s nice to have a small inline valve in the line so that you can let the pressure out of the hose before you disconnect it, but it’s not really necessary, there isn’t much volume in the hose and pressure bleeds off quickly when you loosen the end.

At a Scuba shop the hose is called a fill whip, the whip has two valves on the fill end, one closes off the hose and the second removes the gas from just the end of the hose between the whip valve and the tank valve, that way only a tiny bit of gas is lost.

You can get as fancy as you want, but you only need a couple of tanks. You won’t get full fills of course without a Haskal or similar but as you can refill more often it’s likely you don’t need full fills.

[kortopates]

Novice question about cascade oxygen tanks. 
 
When you decide to take an oxygen line tank off line, say you have 2 tank connections or more, and you remove  the low tank to be filled later there appears to be no inline valve separating the two tanks. So do you need to disconnect the 2 tank system and replace it with  single tank trans filler , just not use it until the empty cylinder comes back, or just have extra cylinder and valve so you can continue to use the remaining source tank until the low cylinder is filled?
 
 

Seems like your inventing an issue that doesn’t exist - at least not in my 20+ years using my transfil system.
When i need to fill a tank, i remove it, put in my vehicle and drive down to my local gas supplier. Although i own my tanks, the gas supplier swaps out my empty for a fresh one and i return to hangar and reconnect it up. The whole process is done in about an hour including the 10-15 min at the gas supplier shop.
My supplier is a big shop so i never have to worry about stock for Aviators O2 (ABO). But if it was a concern i just wouldn’t take my empty tank in till i knew i could swap it out. No need to ever make two trips. Especially with my large tanks that weigh over 100 lbs.


Sent from my iPhone using Tapatalk

[Mac80]

On 11/11/2023 at 7:55 PM, kortopates said:

The whole process is done in about an hour including the 10-15 min at the gas supplier shop.

Thanks for all the good information.  

I am in process of exploring what is needed.

The fill up place in town has to ship my  oxygen tank to St. Louis when they have enough to fill the truck. Airgas says 2 weeks or more. At least that is what they quoted me. 

I am in process of buying one tank and have a trans filler coming that can use 2 tanks.  I have just bought a Trans filler for one tank. An extra tank , or buying only the extra tank valve, or having an in line valve, or plug made might keep me from buying a 3rd tank. I have not seen a reasonable alternative for in-line shutoff with needed connecting hardware.

Also I may have another source for oxygen but he is mostly retired and not likely to continue and may stop working altogether 

One  will do me for a while but seems like waste to have to send it back with 700 or 1000 psi although that maybe cost of the business.

 FBO or other suppliers seem to be  shorting the 2200 psi the tanks hold but maybe they just can’t keep full tanks as they use them to top off and takes some out of the system each time they are used.

 

[DonMuncy]

A trip to the Home Depot brass fitting department will get you a couple of fittings to make a removable plug.

Yes, it always aeems a waste to fill a tank with a substantial amount of O2 still in it, but there is no other way.

[Mac80]

Found 340 oxygen plug rated to 3000 psi from western enterprises sold by airgas and advance tools. Appears could seal exit of tanks or trans filler lines.

Chain & Plug Assemblies, Plug Assembly, 3,000 psi, Oxygen, Brass

Features: One and two-piece assemblies provide gas-tight sealing | CGA nut and blind nipple (plug) combination

Testing And Approvals: Meet all CGA Specifications for Sealing Manifolds and Cylinders

$9.56 

airgas

$25..10

Low cost enough  to use as safety seals for your portable  or supply tank. 

 

[Pinecone]

11 hours ago, Mac80 said:

Thanks for all the good information.  

I am in process of exploring what is needed.

The fill up place in town has to ship my  oxygen tank to St. Louis when they have enough to fill the truck. Airgas says 2 weeks or more. At least that is what they quoted me. 

I am in process of buying one tank and have a trans filler coming that can use 2 tanks.  I have just bought a Trans filler for one tank. An extra tank , or buying only the extra tank valve, or having an in line valve, or plug made might keep me from buying a 3rd tank. I have not seen a reasonable alternative for in-line shutoff with needed connecting hardware.

Also I may have another source for oxygen but he is mostly retired and not likely to continue and may stop working altogether 

One  will do me for a while but seems like waste to have to send it back with 700 or 1000 psi although that maybe cost of the business.

 FBO or other suppliers seem to be  shorting the 2200 psi the tanks hold but maybe they just can’t keep full tanks as they use them to top off and takes some out of the system each time they are used.

 

You must live in a very small town. I have 3 different welding gas suppliers in a short radius.  Two are outlets of big chains and one is a local place.  All stock exchange cylinders to swap.  Unless you are sending out your poortable tank.  Some places will not fill a tank at their shop, and that has to go back to the central location

The more tanks in your cascade, the less effect having 1 or 2 tanks out to be filled will effect you.

Yes, sending a tank back with gas in it seems a waste, but the actual cost loss is not that big.  You could also get a second portable tank so you can run one down further to use some of the low pressure gas left.

Or, if you want to change the money, you can get one of the O2 compressors that AH64 mentions, that will take the tank down to near zero and pump it into your tank.

[Mac80]

AOPA December 2023 Dr Brent Blue’s Oxygen is Oxygen great article.

Oxygen on board is not just for flying over Rocky Mts.  

Do it  yourself can be convenient and reasonable.