Would you dive with 3 year old nitrox?

[industrious95]

I was going to do a bay dive this weekend. 15 ft. max. I have an AL80 in the garage with 34% nitrox, filled in August 2022. I "tasted" it and it smells and tastes fine. I know fills are relatively cheap, but I almost always dive with my steel 120's and don't want to get the AL80 hydro'd and VIP'd, which it would need if I got a fresh fill. I'm just gong to get rid of the tank after I use it. The AL80 was filled at a very reputable shop, so it's fair to assume that the original air quality was good. It's just 3 years old.

And I don't want to lug that heavy steel tank around for a 15 ft dive.

Any thoughts on 3 year old Nitrox?

 

[2TH DIVR]

Should be fine.
I just blended some nitrox with some O2 that was filled 28 yrs ago.
Came out fine.

 

[tursiops]

Analyze it before you use it.

 

[The Chairman]

Analyze it before you use it.

Please.

 

[lowwall]

Analyze. The concern is oxidation substantially reducing the available O2 in the tank, although I'm struggling to come up with how this could happen in an AL tank. Regardless, analyze and if it's still 34%, you are good to go.

 

[tursiops]

Analyze. The concern is oxidation substantially reducing the available O2 in the tank, although I'm struggling to come up with how this could happen in an AL tank. Regardless, analyze and if it's still 34%, you are good to go.

Also, the concern is a mislabeled tank.

 

[lizardland]

I have bailout bottles that I use for CCR diving that must have been filled 10 years ago.

 

[davecampbell]

I was given a pair of steel galvanized 72s with around 1500 psi in each of them. A friend found them stashed away at an estate sale. Their last visual inspection was in May of 1979 ( the month and year I was born). While I didn't dive the air, I did test them for O2 content and CO. They came back 20.9% and 0.00 ppm. The gas smelled and tasted normal. Tanks were absolutely pristine inside... 3 years? I wouldn't sweat it at all...

 

[tursiops]

I was given a pair of steel galvanized 72s with around 1500 psi in each of them. A friend found them stashed away at an estate sale. Their last visual inspection was in May of 1979 ( the month and year I was born). While I didn't dive the air, I did test them for O2 content and CO. They came back 20.9% and 0.00 ppm. The gas smelled and tasted normal. Tanks were absolutely pristine inside... 3 years? I wouldn't sweat it at all...

Would you have dived those tanks without testing them? THAT is the issue.

 

[davecampbell]

Would you have dived those tanks without testing them? THAT is the issue.

there's a vast difference between a steel cylinder with a 46 year old fill, and an aluminum cylinder with a 3 year old fill. I have aluminum 80s in my workshop right now that have were filled more than 3 years ago. I'd dive them without fretting over it. I know where they were filled, and what's in them. The steels, by virtue of the fact they were filled when I was an infant, were a complete unknown. I analyzed them more out of curiosity than anything else, but after seeing the inside condition of the cylinders, I'm not surprised they tested fine...