Aerox O2 tank refill

[N201MKTurbo]

1 hour ago, Pinecone said:

Same with a manifold.  The combustion pressure can be above the manifold system.

Any SMART welding setup has flashback arrestors, that are one way valves to prevent this from happening.

But the shop I deal with doesn’t fill welding bottles from the manifold for that reason. 
 

They say the bottles that combust aren’t from professional welding shops, but mostly from home shops.

[Pinecone]

Makes sense.  With a cascade you probably only have to dump the low pressure cylinder, and not waste too much product.

 

[EricJ]

10 hours ago, N201MKTurbo said:

I asked them if a cylinder ever exploded while doing a hydro test? They said only once. They were testing a batch of 10000 PSI cylinders from the Air Force base and there was an identical 3000 PSI cylinder in the bunch. It exploded in the hydro test tank and shot through the roof of the building. Luckily no one was hurt. He said it put them out of business for a week.

I thought the whole point of doing the test hydrostatically in a tank was that since water is incompressible there's little stored energy if the tank bursts, so it just goes plop instead of shooting through something.

[N201MKTurbo]

1 hour ago, EricJ said:

I thought the whole point of doing the test hydrostatically in a tank was that since water is incompressible there's little stored energy if the tank bursts, so it just goes plop instead of shooting through something.

Thunderbird cylinder (40th street and University) fills the cylinders with compressed air and measures the displacement of the cylinder. I had the same concern as you. They said that would take too long and they would need to dry all the cylinders. Right now they have one hydro station and do hundreds of cylinders a day. It takes them about 3-5 min per cylinder. 

[FlyingDude]

 is hydrostatic test mandatory for all tanks or for those that go in planes only?

[N201MKTurbo]

9 minutes ago, FlyingDude said:

 is hydrostatic test mandatory for all tanks or for those that go in planes only?

It isn’t actually required for aircraft unless it is in the ICA. Which it probably is.

The DOT requires it for any cylinder used in interstate commerce. Most people will not fill a cylinder if it is out of hydro.

My portable cylinders are out of hydro. It is perfectly legal for me to fill them myself and use them in my plane. If I’m on the road, I won’t be able to get someone else to fill them.

[FlyingDude]

Where do you get it tested? How much does it cost?

[N201MKTurbo]

1 minute ago, FlyingDude said:

Where do you get it tested? How much does it cost?

I get it done at Thunderbird Cylinder, which changed its name. Last time I got a cylinder tested, it was $25. Someone on yelp said they doubled the price after the acquisition. 
 

Most major cities have at least one cylinder shop. Just call the local gas distributor and ask them where they get their hydro tests done.

[N201MKTurbo]

26 minutes ago, FlyingDude said:

Where do you get it tested? How much does it cost?

Or, buy a set of stamps and pencil whip it….

[EricJ]

2 hours ago, N201MKTurbo said:

Thunderbird cylinder (40th street and University) fills the cylinders with compressed air and measures the displacement of the cylinder. I had the same concern as you. They said that would take too long and they would need to dry all the cylinders. Right now they have one hydro station and do hundreds of cylinders a day. It takes them about 3-5 min per cylinder. 

That's nuts.   I hope they don't get somebody hurt.

[carusoam]

Scuba tanks also go through the hydro testing schedule…

And… you may find the aluminum tank you have lives part of its life at 3kpsi, before five years… and may get lowered after then…

Old memory of Scuba tank maintenance…

And of course… Kevlar tanks are different as well…

 

Holy cow… 10kpsi… that is a lot of energy to stuff into a 3kpsi tank… it probably failed at 6kspi… as it ran through the designed safety factor…

Pp thoughts only…

-a-

[FlyingDude]

sooo, I got myself a full O2 cylinder from a welding supply company and they said to vent the gas and get it refilled at a scuba shop because theirs is industrial O2 and should not be breathed...

Was he just hedging against liability or is there truth to it? Some of your commented that you get your gas from welding companies. So is it like some have clean O2 and some have unpure O2?

 

[jaylw314]

34 minutes ago, FlyingDude said:

sooo, I got myself a full O2 cylinder from a welding supply company and they said to vent the gas and get it refilled at a scuba shop because theirs is industrial O2 and should not be breathed...

Was he just hedging against liability or is there truth to it? Some of your commented that you get your gas from welding companies. So is it like some have clean O2 and some have unpure O2?

I use "unpure" O2 all the time then  My welding shop does also have USP oxygen available, which is apparently what medical supply uses, but they require a prescription for that.

My understanding is that standard oxygen is purified by concentrator and compressed, so it's not as pure, but the main contaminant is nitrogen.  I suppose there could be other contaminants, but I've never smelled any organic or solvent odors (and I have to wonder if anything can even survive in 95% oxygen for very long without getting completely oxidized).   And then you're diluting it by 1/5 or more when you use a nasal cannula.

[neilpilot]

12 minutes ago, jaylw314 said:

My understanding is that standard oxygen is purified by concentrator and compressed, so it's not as pure, but the main contaminant is nitrogen.  I suppose there could be other contaminants, but I've never smelled any organic or solvent odors (and I have to wonder if anything can even survive in 95% oxygen for very long without getting completely oxidized).

Maybe the source of O2 differs depending on the specific location.  Before I retired from the chemical industry, I sometimes visited a couple of liquified and compressed gas distributor sites.  I can say that the 2 major distributors of oxygen that I was familiar with each had a single bulk O2 cryogenic storage and vaporization system.  They both filled medical and welding O2 cylinders from the same system.  While the cylinder procedures may have differed, the O2 going into the cylinders was exactly the same.

[N201MKTurbo]

18 hours ago, carusoam said:

Scuba tanks also go through the hydro testing schedule…

And… you may find the aluminum tank you have lives part of its life at 3kpsi, before five years… and may get lowered after then…

Old memory of Scuba tank maintenance…

And of course… Kevlar tanks are different as well…

 

Holy cow… 10kpsi… that is a lot of energy to stuff into a 3kpsi tank… it probably failed at 6kspi… as it ran through the designed safety factor…

Pp thoughts only…

-a-

They said it failed just below 10K PSI. 

[jaylw314]

3 hours ago, neilpilot said:

Maybe the source of O2 differs depending on the specific location.  Before I retired from the chemical industry, I sometimes visited a couple of liquified and compressed gas distributor sites.  I can say that the 2 major distributors of oxygen that I was familiar with each had a single bulk O2 cryogenic storage and vaporization system.  They both filled medical and welding O2 cylinders from the same system.  While the cylinder procedures may have differed, the O2 going into the cylinders was exactly the same.

I suspect it varies geographically.  It may be that shops closer to distribution centers find it is more cost-effective to use cryo oxygen, and those farther away find it more cost-effective to use an industrial concentrator and compressor.

[DonMuncy]

6 hours ago, FlyingDude said:

sooo, I got myself a full O2 cylinder from a welding supply company and they said to vent the gas and get it refilled at a scuba shop because theirs is industrial O2 and should not be breathed...

Was he just hedging against liability or is there truth to it? Some of your commented that you get your gas from welding companies. So is it like some have clean O2 and some have unpure O2?

 

Absolute BS. It all comes from the same source. My understanding is that some applications require testing for H2O content, but it still comes from the same source. 

[Skyland]

Like Duff beer?

https://youtube.com/clip/UgkxBWP4aC22lt3VgzOQ2PcK92thFI7DN-I9

[carusoam]

Essentially O2 is O2….

Because the process of separating O2 from everything else is so demanding… it is easily separated from everything else…

When it comes to impurities…. You won’t find any organic solvents accidentally in your O2….

 

Be familiar with the safety issues of mishandling pure O2… anything that can burn, like a solvent, fuel, oil, or grease…. Is easy to light itself on fire just for being in that environment…

Remember to clean your tools, so there is no flammable stuff on them…

 

Adding water to your O2 is often done in the home environment… if you are breathing this stuff all day every day…. In large quantities…

The challenge of having H20 in your O2…. It is possible for it to form ice in your regulator causing a blockage…

 

It would be pretty hard to get water with your O2 because it would get separated out early on in the process…

 

Many MSers use O2 from all of the various supplies…

 

I can see how an empty welding O2 tank can end up with acetylene in it…. But I can’t see an O2 tank full of O2 with acetylene in it… like oil and gasoline… acetylene wants to burn…. Mixing them together is somewhat bomb like…. (?)

 

Best regards,

-a-

[N201MKTurbo]

46 minutes ago, DonMuncy said:

Absolute BS. It all comes from the same source. My understanding is that some applications require testing for H2O content, but it still comes from the same source. 

I asked the guy at the gas company what they do different for ABO. He said they test for purity and moisture. I asked if it ever failed. He said not once in 20 years.

[N201MKTurbo]

32 minutes ago, carusoam said:

Essentially O2 is O2….

Because the process of separating O2 from everything else is so demanding… it is easily separated from everything else…

When it comes to impurities…. You won’t find any organic solvents accidentally in your O2….

 

Be familiar with the safety issues of mishandling pure O2… anything that can burn, like a solvent, fuel, oil, or grease…. Is easy to light itself on fire just for being in that environment…

Remember to clean your tools, so there is no flammable stuff on them…

 

Adding water to your O2 is often done in the home environment… if you are breathing this stuff all day every day…. In large quantities…

The challenge of having H20 in your O2…. It is possible for it to form ice in your regulator causing a blockage…

 

It would be pretty hard to get water with your O2 because it would get separated out early on in the process…

 

Many MSers use O2 from all of the various supplies…

 

I can see how an empty welding O2 tank can end up with acetylene in it…. But I can’t see an O2 tank full of O2 with acetylene in it… like oil and gasoline… acetylene wants to burn…. Mixing them together is somewhat bomb like…. (?)

 

Best regards,

-a-

He said it makes a loud pinging sound right after you start filling it. They will send it out for a complete overhaul after that.

[Pinecone]

The OWT of different types of O2 was debunked some 25 years ago.  Look at the archives of AVWEB.

All O2 comes from liquid oxygen.  It all comes from the same source.  If medical O2 had more moisture, why do hospitals and full time home use add bubbling through water to humidify it?

MANY people have been filling their aircraft O2 tanks with welding O2 for many years.  And the O2 system manufacturers sell the setups to fill your internal or portable tanks from welding O2 tanks.

FAQ from Mountain High - https://www.mhoxygen.com/348-what-are-the-different-oxygen-types/

 

 

 

[FlyingDude]

11 hours ago, carusoam said:

Remember to clean your tools, so there is no flammable stuff on them…

How? With alcohol and acetone?? They burn too? Or just wait for them to evaporate?

[Marauder]

How? With alcohol and acetone?? They burn too? Or just wait for them to evaporate?

Oxygen is an oxidizer. It “combusts” readily when expose to a petroleum source. Any fast evaporating solvent is fine to clean the orifice with. Also, if you keep a cylinder without your cannula adapter attached, you’ll want make sure you keep a cap on it.


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[jaylw314]

51 minutes ago, Marauder said:

Oxygen is an oxidizer. It “combusts” readily when expose to a petroleum source. Any fast evaporating solvent is fine to clean the orifice with. Also, if you keep a cylinder without your cannula adapter attached, you’ll want make sure you keep a cap on it. 

And if you ask at a welding shop, they'll be happy to give you a bunch