converting air tanks to EAN

[antattack]

I do enjoy supporting my LDS

 

[gcarter]

Fortunately, my LDS uses a small strip of masking tape with the mix written on it. They do sell those silly giant green stickers, but probably feel bad about doing so.

I have 2 tanks with an O2 vis sticker, and 4 with regular vis stickers accompanied by stickers indicating banked ean only. None of the 6 have nitrox wraps, and I pretty much always use nitrox.

 

[NAM001]

Not to pick a fight...What is teh deel with something about >50psi and o2 > 23.5% requireing cleaning. Seams like i picked that up in a psi course, maybe not. CGA reg or something. But when i heard it We were discussing piping and systems that pipe E hiperfiltered or nitrox must have sepaerate piping than air that is non- e-hiperfiltered. Running regular air required the recleaning of teh whoe o2/hyperfitered delivery system because of contamination. I remember yea ok for a test but not in my real life. I am sticking to the 40% line nthe sand. Perhaps someone can clarify.

 

[Kitty_Kat]

The position of the major agencies at the moment (dive theory/DM/instructor teachings) says that tanks really only need to be O2 clean if partial pressure blending is used. This is the position my LDS takes, but since we have banks of 32% and 36% most people that only use my LDS don't bother. In my mind it's a simple rule of thumb: if you know the inside of your tank will never be exposed to a percentage of O2 higher than 40%, it's probably not worth the money to have it O2 cleaned. But if you want to be able to fill your tank with Nitrox anywhere, get it O2 cleaned.

For my work, we use many different types of pressured gases in our lab and therefore have to follow quite a few regulations. Most of the restrictions about oxygen systems do not apply to SCUBA tanks though, including the one that was posted earlier.

Personally, I will always get my tanks O2 cleaned because I like being able to get them filled in different places without worry. It is too easy for a system that blends nitrox to make an incorrect mix with a high o2% and for that mix to end up in your tank. The concerns around O2 cleaning make a lot more sense if you have seen a fire or explosion that was induced by pure oxygen.

 

[fjpatrum]

I got two of my 3 tanks done the last time they went in for Viz. They were supposed to both be O2 cleaned but it turned out only one was labeled as such. Caused a problem for me getting EAN in Florida, of all places. One of the shops would only fill the O2 cleaned tank.

Personally, I think it's a bit silly, but the reality is O2 cleaning is meant to keep the tank fill person from getting hurt, as unlikely as that is. As such, I'll keep getting my Nitrox tanks O2 cleaned. My shop requires the stupid Nitrox stickers but I just use them as a marker band for where to put my tank bands and ignore the gawd-awful things other than that.

 

[Scared Silly]

This is incorrect. If you read CFR 49 171.7 it incorporates CGA G4.1 only as it applies to CFR 49 178.338-15. 178.338-15 relates to the required cleaning for a cargo tank ...

Actually it is correct, one needs to fully read the text including the precursor text.

Read page 93 here:


http://www.gpo.gov/fdsys/pkg/CFR-2011-title49-vol2/pdf/CFR-2011-title49-vol2-sec171-7.pdf


And in particular this paragraph.


(3) Table of material incorporated by reference. The following table sets forth material incorporated by reference. The first column lists the name and ad- dress of the organization from which the material is available and the name of the material. The second column lists the section(s) of this subchapter, other than §171.7, in which the matter is referenced. The second column is presented for information only and may not be all inclusive.


The key here is the last sentence which states that the second column (i.e. the reference to CFR 49 178.338-15) is for information only (i.e. a case where the particular material is specifically referenced with in a chapter but is not all inclusive). Thus all of CGA 4.1 pertains and is applicable to portable cylinders.

 

[adutto]

So...
I'm still confused... Here's what I have so far:

- If partial blend => Clean the tanks
- If NOT => Use the tanks as they are?

Other than the explosion issue, is it there other risk? or everything goes back to that?

Sorry for the dumbness, I need to decide on my used (10 dives) tanks' destiny.

Thanks!

 

[Scared Silly]

So...
I'm still confused... Here's what I have so far:

- If partial blend => Clean the tanks
- If NOT => Use the tanks as they are?

Other than the explosion issue, is it there other risk? or everything goes back to that?

Sorry for the dumbness, I need to decide on my used (10 dives) tanks' destiny.

Thanks!

You are confused because of the ad-hoc nature of the dive industry.

This report might of interest: http://www.si.edu/dive/pdfs/proceedings_DANnitrox.pdf

FWIW - my cylinders are O2 clean.

 

[WheelsUSN]

I see what you are saying - that reg was passed to me from Mark Gresham from PSI in a discussion and I never followed through on reading it. I will check with him.

Unless Mark Gresham is a lawyer specializing in transportation of HAZMAT his opinion probably isn't worth much more than yours or mine. I am not a lawyer but I have been trained in Transportation of HAZMAT by the government. You have to remember that PSI has a business interest in making people believe that O2 cleaning is necessary so that they can sell courses to teach people how to do it. I don't have any financial interest in whether or not you O2 clean anything. However I will refuse to fill your non O2 cleaned tank if it will need a higher percentage of O2 than what I have banked therefore requiring partial pressure blending.

 

[Peter_C]

The dive shops own the compressors and supply the fills at their discretion. If you want to know if they require O2 cleaning call or walk in, and ask what their requirements are. They each seem to have their own set of rules.