Nitrox Storage Question

[String]

s it OK to dive the tanks then take them in for the VIP?

Use the tanks and then get them tested. Absolutely no issues storing it at all even for decades.

 

[Cave Diver]

Use the tanks and then get them tested. Absolutely no issues storing it at all even for decades.

Assuming that they were in good condition when stored.

 

[Brewski]

Could you explain why? If the tanks were properly cleaned for O2 then filled with any mix they should be fine. What do you base your statement on. I have a couple 72's that get used very infrequently and after I get them down to 1500 or so doing regs on my bench I'll use them for 1 dive before refilling. That may take 6 months and there's never been a problem. I had one that I finally used after sitting for 9 months and it was good.

after reading this http://www.scubaboard.com/forums/3966363-post6.html I'd reevaluate my thinking.
I now think it would be prudent to re analyze the contents before just going out to dive them, if there is a significant drop in O2 percentage, that could indicate corrosion is taking place.

 

[String]

Corrosion isnt going to take place on a sensible time scale due to a slightly increased oxygen level at all.

..and even if the tanks weren't in great condition to start with you can still use the gas then worry about it.

 

[iztok]

Could you explain why? If the tanks were properly cleaned for O2 then filled with any mix they should be fine. What do you base your statement on. I have a couple 72's that get used very infrequently and after I get them down to 1500 or so doing regs on my bench I'll use them for 1 dive before refilling. That may take 6 months and there's never been a problem. I had one that I finally used after sitting for 9 months and it was good.

Here is why: http://www.scubaboard.com/forums/ta...-cylinder-long-term-storage-fact-fiction.html

 

[UCFKnightDiver]

Just analyze the tanks.... and if they check out dive them. Chances of AL oxidizing is slim as it is.

 

[HowardE]

Here is why: http://www.scubaboard.com/forums/ta...-cylinder-long-term-storage-fact-fiction.html

Citing a 30 year old study?

 

[Doc Harry]

Citing a 30 year old study?

If you can find more recent studies and data, please, present what you have.

Until then, a 30-year old study is all there is.

 

[Cave Diver]

In 1974 there was one documented case of a death that was caused by breathing a corrosion-induced hypoxic mixture.

In this case, the diver took a steel tank to a depth of 12 feet to search for an outboard motor. The victim had last used this tank three months previously and it only had 300 psig remaining. Five minutes into the dive his bubbles were noted to cease and his body was later recovered.

Analysis of this accident revealed severe corrosion of the tank with large amounts of rust. There was 200 psig remaining but the oxygen content of the gas was measured to be only 2% to 3%.

The steel tank in this accident had neither a current hydro nor a current visual inspection. (The last documented visual inspection was in 1964.)

It looks like there were several contributing factors to this analysis. Sitting for 3 months only played a small part in it. The fact that it hadn't been visually inspected in 10 years and was stored with only 300 psi are most significant facts in my opinion.

 

[String]

5 MINUTES into his dive on 2-3% oxygen before stopping? Somehow i doubt anyone would last THAT long!