How many of you have failed to analyze a tank that you thought had air?

[corvettejoe]

Two questions? Has anybody tried the Cheap Nitrox anylyzer? I'm considering one of these.
Also, once the tanks are O2 cleaned, if you put air in, is that okay?

Remember what Nitrox is... it's just air with more oxygen added to it (and therefore less nitrogen to ongas) thus "Oxygen Enriched Air"

The reason it needs to be specially cleaned for oxygen is because of the much higher content of oxygen in nitrox than in air. There are certain chemicals/materials/elements that can cause reactions with oxygen at higher levels and go BOOM under certain conditions. Cleaning the tank just removes all the contaminants that may cause a reaction like this to happen.

Once it's cleaned, you can put anything you want in it.

The o2 cleaned VIP labels just tell a dive shop that it's safe to put a higher-than-air oxygen mix into the tank. It does not make it "nitrox only".

Most of my "o2 cleaned tanks" have air in them currently.

 

[Gren]

Once it's cleaned, you can put anything you want in it.

You can put anything you want in it as long as it's O2 compatible. Otherwise it's no longer O2 clean.

 

[CT Sean]

And a tank that was O2 cleaned and labeled as 02 with an FO2 of 98%.

Wait so all this is because he (I assume he) thought it was air when it was label O2 or that it was incorrectly labeled O2 when it was actually air?

 

[chrpai]

Wait so all this is because he (I assume he) thought it was air when it was label O2 or that it was incorrectly labeled O2 when it was actually air?

That incident is what sparked all of this recent conversation. The speculation / second hand accounts from that incident was that he was a tech / cave diver who grabbed a stage bottle that he had clearly labeled as O2 MOD20 and took it for travel gas. His buddies said "yo, what are you doing?" and he said something to the effect of "oh that's wrong, I know it has air in it".

It was a tragic for sure. And I think there is a lesson to be learned for mixed gas divers. But I'm not convinced that lesson should be extended in the way being suggested.

I bought an AL40 from a local tech diver last year. IT was O2 clean and had 100% O2 in it and was marked O2 MOD 20. Although it looked cool I peeled all of the stickers off and had it VIP'd for air service only. I have since only put air in it. I'm not about to test that tank or any of my other similar tanks for O2 every time I get them filled.

 

[rhwestfall]

once the tanks are O2 cleaned, if you put air in, is that okay?

big debate here...

the shop I use has what is called "ultra pure" air (filtering process). Filling O2 cleaned tanks with this is not considered a problem. They also PPBlend, needing to maintain O2 clean status. All works fine together.

 

[CT Sean]

Based on that I fail to see how the "solution" address the problem statement.

 

[corvettejoe]

You can put anything you want in it as long as it's O2 compatible. Otherwise it's no longer O2 clean.

You can't breathe much else beyond oxygen, nitrogen, helium.
Most people aren't going to get into the weird exotic gasses and even then it's still o2 clean. Just drain the tank and fill with something else. Those alone don't cause combustion with oxygen. It's things like rust, grease, oils, etc that they are cleaning out of the tanks.

If a shop tells you otherwise they are pulling your leg to see you something.

 

[dfx]

big debate here...

the shop I use has what is called "ultra pure" air (filtering process). Filling O2 cleaned tanks with this is not considered a problem. They also PPBlend, needing to maintain O2 clean status. All works fine together.

That's what I've been told as well. If the air fill isn't "ultra pure", then the tank would lose its O2 rating.

 

[ScubaSteve]

And I think there is a lesson to be learned for mixed gas divers. But I'm not convinced that lesson should be extended in the way being suggested.

Sometimes people would prefer to recommend something and look proactive (or having a purpose) than to recognize that sometimes people don't follow the rules that are already out there and sit back and look stagnant (or having no purpose). In a case like this, I think it would have been prudent to check the contents and then do the dive (or not if the contents proved to be unsuitable). For the NACD and others to advocate additional content checks is not necessarily the solution because, fact is, sometimes people do not follow the guidelines. Complacency / Rushing can happen to anybody. I am also not against people adding an additional step to a pre-dive for safety. I am against it being mandated in an effort to correct for the people that already choose to not follow the guidelines. It is like adding more gun laws to control people that do not follow the laws in the first place.

If we want to check the contents again to feel safer, then I will happily give up that 2-3 minutes. Sometimes :turd: can unexpectedly happen and that tank that you KNOW cannot have a rich blend in it, (or high CO or He), will have it. I say nothing is impossible but I also will not expect anybody to go to extreme optional lengths for the very rare possibility.....unless my buddy wants to.

 

[cruiser]

Now if BlackBeard's could install a membrane system by Sep 6th.

I second Blackbeard's installing a membrane system