Getting 100% O2 fills?

[Wookie]

So, here is the deal with those cylinders. They are filled with medical oxygen. Medical, get it? Medical gas is traceable from the point of filling with a serial number denoting the batch it was filled with and tested to be breathing quality. That way you don't get welding oxygen or cutting oxygen or anything except for breathing grade. There are 2 breathing grades, medical and Aviators Breathing grade. Both have batch numbers on them. The only reason this is important is if you actually need it. So, if you need it, and you use it, and the victim die, guess what, everyone's going to court. Someone will ask if the o2 was medical grade. If the answer is no, you just lost the fight.

my advice is to check the local laws, and get the gas at the local Airgas or other gas shop, and get medical O2. A cylinder costs less than 10 bucks. It comes with a cert. yes, I can fill them myself. I don't. Pat of the reason is that even though I own my own cylinders, I don't use enough medical o2 to even use up the tanks before they are due for hydro. If I trade tanks at the gas house, they get the expense of hydro and refill, too.

 

[kelemvor]

I present my DAN o2 provider card to buy o2. Of course, I've only done it once and still not used the gas.

 

[Akimbo]

Not sure about local laws, but the commercial diving industry uses what can be called “welding” grade. This is because the gas produced by major suppliers is through a cryogenic process of compressing and cooling air then separating the gasses in a tower. That is also how the vast majority of Nitrogen and Argon is produced.

Aviation and Medical Oxygen comes out of the same tower and goes into the same steel cylinders except for the chrome valves. I have seen gas chromatograph reports that confirm the purity of industrial, aviation, and medial grades are the same... 99.997% as I recall. If you look in the back of any industrial gas supplier's shop you will see plated and unplated valves on cylinders being filled off the same manifold.

The great majority of hospitals and large weld shops get their Oxygen in cryogenic form or LOX (Liquid OXygen), which saves some production steps. The diving industry would use LOX except we need the high pressure. We purchase oxygen in large manifolded packs of 6-18 230 Ft³ cylinders protected by a steel cage for small operations. Oxygen comes in tube trailers for big jobs.

 

[grey2112]

So, let me ask this - if I have these O2 tanks and they sit, unused, about how long would I expect them to stay pressurized? Anything special I need to do for them or to them every "x" years?

 

[claymore]

If the valve and neck seal are good they will hold pressure almost indefinatly. Hydro every 5 years and that should be it.
Some one else may have more info on the maintenance.

 

[tech_diver]

a couple of random things...

Most tekkies have known that all the different grades of oxygen from major suppliers come from the same spigot. It's just the paperwork that is different. But as Capt Wookie pointed out, if there is an incident, it will all be about the paperwork. When you apply the term 'medical' to anything (gear, gas or people), you move to whole 'nuther level.

It's been a few years since I've bought med O2 but I remember that it is highly regional. Health insurance is managed by state government and the insurance companies have a big impact on the rules about when there should be a prescription or not. If you cross state lines, you can get a whole different story.

When I was mixing my own deco gases, I used welding grade all the time. ... same as the other grades... tastes like chicken

 

[Akimbo]

… But as Capt Wookie pointed out, if there is an incident, it will all be about the paperwork…

This might be a good reason for the OP not to get a cert for administering oxygen, especially where freedivers are concerned. The card could increase liability.

[hijack]I just received a private E-mail from a friend on this thread. It basically asked “What the hell are you using tube trailers of oxygen for?

Fair question since metabolism of oxygen doesn’t change consumption rates with depth. Tube trailer quantities of O2 (in the hundreds of thousands of cubic feet range) is required for big burning jobs — cutting metal underwater with an Oxy-Arc cutting torch.

BR-22 PLUS Underwater Cutting Torch - Broco-Rankin

Oxygen flowing through the torch is depth dependent. [/hijack]

 

[DivemasterDennis]

I have no special certification, but have an)2 emergency rig. My LDS arranges for fills for me at their cost. No harm in asking them.
DivemasterDennis

 

[Mustard Dave]

Duff Aviation, Duff Medical, Duff Welding

 

[FinnMom]

What about the legalities? Is there a danger of being sued if you administer O2, or just recommend and provide O2 etc. when you are not a liscensed physician etc. ?

The USA's reputation is that when things go badly the search for guilty parties can get a bit enthusiastic.