medical oxygen question

[Dr Pokenhiemer]

Now you guys are making me worried about a decompression in my air ambulance!!! We have the main takn under the stretcher and a couple of spare tanks. KA-BOOM!?

 

[avbug]

No, no kaboom. Pressure cylinders are required to undergo hydrostatic testing regularly, depending on the type of material and any specific manufacturer recommendations. Generally steel cylinders are on a five year hydrostatic test requirement, while carbon fibre and lightweight cylinders go on a three year cycle. You can check for this date on the cylinder itself; it will be stamped into the neck, and each subsequent test date will be stamped there.

Airlines do not choose their oxygen equipment because it's somehow tougher and able to be dropped. The requirement that an airline use their own equipment is because it's been under their approved maintenance program and control; it's a known quantity and quality. There is no determination made or able to be made regarding a foriegn or unknown piece of equipment brought on board. You could check the hydrostatic test date, but you have no way of knowing if the cylinder has been purged with each filling, how many fillings it's had, or it's maintenance or history life. You have no way if it's been kept dry, or if it suffers internal corrosion due to moisture from improper filling or storage.

Your King Air probably uses a standard steel E cylinder under the litter. The risk of the cylinder exploding is a non-issue. With oxygen cylinders, you should be far more concerned about the regulator attachments. Break these and the cylinder may become a missle with a mission. Your smaller portable bottles, often stored at the back of the airplane to use when onloading and offloading y our patient, are a far greater potential for damage, especially from dropping.

You're probably already familiar with the requirements to crack the valve slightly and open it slowly, to never position yourself over or adjacent to the valve, to refill it slowly, to avoid proximity to petroleum products (which can self combust in the presence of pure oxygen), etc. These are far more important to your longevity than wondering if the cylinder is going to go kaboom. It isn't.

 

[Dr Pokenhiemer]

Thanks Avbug, but I was just being a little sarcastic. We have an H-tank on the Lear. The drawback with having such a large tank back there is that when my medical crew gets in a farting contest, they have more O2 back there than I do in the acft tank up front!!

 

[Well-hung Start]

there are 3 kinds of "oxygen"

Dudes:


The aviation field has a history of being clueless about oxygen. I remember a ridiculous assertion from an "authority" that "welder's" and "medical" oxygen are different from "aviators" oxygen.

Oxygen is O2 no matter whether you're fusing steel, rapidly decompressing, farting, or having chest pain. And the physics of compressing it into a tank at 1800 psi is identical: it must be PURE and it must be DRY.

So bite me! Or breathe me! Whatever!

one last note.....The most probable mechanism-of-injury from an oxygen "bottle" (over-engineered steel vessel) is DROPPING IT ON YOUR TOE.

 

[cvsfly]

Pardon my cluelessness. We have always been told that the differance between medical and aviator O2 is the moisture content. Aviator's being drier due to freezing concerns. It makes sense to me that filling any tank you would not want moisture in it. Where is the moisture added to medical O2? For those 135 operators that do accept passenger carry-ons in accordance with 135.91(a), what documentation do you ask for to conform with 135.91 (a)(1)(i)?

 

[avbug]

Until Mr. well hung jumped in with his outfield bite-me comments and introduced the topic of mositure in 02, it wasn't part of this thread. However, now that it's been brought up, all 02 is indeed the same. In medical oxygen, moisture is introduced during the 02 flow to the patient, usually at or after the patient regulator.

There is absolutely no difference between welding oxygen, medical oxygen, or aviators breathing oxygen, except for price. There is no difference in purity or moisture content. Only price. All three products come from exactly the same source, and are exactly the same product.

 

[Well-hung Start]

Avbug is right

Well-stated, Mr. 'bug.

But your final incisively-distilled definitive authoritivity seems to have ended the thread.

I want to keep it going, since this is the only aspect of aviation I always get the right answers to!

Any other Oxygen questions out there? Comon!

 

[A Squared]

Here's a link to an article which discusses the oxygen issue in a little more depth.


http://www.avweb.com/news/columns/182079-1.html