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LKunze · 06-16-2003, 02:28 PM,

Maximum Operating Depth

JoelW · 06-16-2003, 03:03 PM,

Ask for the normoxic nitrox. The question that I have for places that fill with nitrox is what process do they use for getting the air that they mix the O2 with. Is the air they pump good enough to make the nitrox or not. If so, what's the problem with putting it in a nitrox marked tank. If not, are you sure you want air from there anyway. Or are they doing the nitrox from a bottle of nitrogen and oxygen.

JoelW

***jasondbaker*** · 06-16-2003, 04:30 PM,

Joel, he focused on the potential liability of someone using a tank with a nitrox sticker filled with air and thinking that it had nitrox. The person goes out and dives the cylinder and gets bent.

I have my dive computer set permanently to NITROX mode. I adjust the o2% on each dive depending on what is in the cylinder. So even if the cylinder has a nitrox sticker on it I can't just jump in the water and start diving. I have to make note of the contents, plan my dive, and set my computer accordingly. The green nitrox sticker should have no impact on my dive plan. The only thing that matters is the contents label.

It seems like the diving community would be better served by eliminating the big green nitrox sticker. If the tank is o2 cleaned then you can get partial-pressure fills -- otherwise premix (up to 40%). The shops should just put a contents label on each tank after a fill and be done with it. The current "system" is confusing for divers and is not standardized from one shop to the next.

ScubaDiveandTravel · 06-16-2003, 05:03 PM,

Here's my understanding on things guys. The DOT cannot regulate the filling of cylinders, only the transportation of cylinders. They have no authority over dive shops whatsoever. As far as not filling nitrox tanks with air, that's pretty absurd considering air is nitrox (EAN21.) If you have continuing problems with that particular shop, I heard there is a new one that opened up that way.

LKunze · 06-16-2003, 05:05 PM,

That doesn't make any sense at all...that's what the content label or piece of duct tape is for...to tell you what's in the tank.

beeger · (This post was last modified: 06-17-2003, 07:38 AM by beeger.)

Wow. There are at least 2 or 3 things wrong with that statement (his statement, Jason, not yours). Even people who believe in/like those big green nitrox stickers know that the tank must be labeled with the exact contents. It's really discouraging when you see a shop owner - the type of person that should be in the forefront of this stuff - adhering to some sort of Byzantine mentality around O2/nitrox. > Sad

Sorry you guys had the bad experience.

***jasondbaker*** · (This post was last modified: 06-17-2003, 12:25 PM by jasondbaker.)

I have an update on this thread. The question is: can you put air in a cylinder marked with a NITROX sticker? Corey with PSI (Professional Scuba Inspectors, Inc.) was kind enough to respond to this question.

Corey:

...I want to make sure I am clear in saying you must not
fill a cylinder with a gas other then what the cylinder is marked for. Cylinders with no markings are generally assumed to contain non-hazardous air. Air being define as 21% O2 & 78% N2 with less then 1% other gas. So, in the case you described, a Nitrox cylinder must be drained completely, given a complete visual inspection (PSI policy), and any Nitrox markings (stickers) removed prior to refilling it with air.

The specific legal citation for removing the stickers comes from the DOT and is stated in Code of Federal Regulations Title 49, Subtitle B, Chapter 1, Part 172, Subparts D & E.

Line 172.303 (a) of D states "No Person may offer for transportation or transport a package which is marked with the proper shipping name or identification number of a hazardous material unless the package contains the identified hazardous material..."

Line 172.401(b) of E states "No person may offer for transportation and no carrier may transport a package bearing any marking or label which by its color, design, or shape could be confused with or conflict with a label prescribed by this part."

You may read these citations in full content at:

DOT considers any gas with greater then 21% O2 to be an oxidizer and labeled as such. The Nitrox label indicates this and by putting air in a cylinder marked for Nitrox, you are in violation of several DOT regulations.

LKunze · (This post was last modified: 06-17-2003, 01:16 PM by LKunze.)

LOL...good thing there is only one shop in the state that adheres to this. Wink

But...again I don't get it. Air is 21% nitrox. The nitrox label doesn't say anything about the mixture content's O2 percentage that is what the content label is for. So the percentage in the tank is irrelevant to the large Green and Yellow Nitrox Label. : Smile

06-17-2003, 01:43 PM,

Of course we dont get it!
Rational thought and government regulation are generally incompatible.
Tongue

Skruff · 06-17-2003, 01:59 PM,

I guess I don't see the point to not allowing air in a nitrox tank.... As long as it's marked correctly who cares... If anything when you go to get it filled leave the rest of your last nitrox fill in the tank and analize it after the air fill. If you get 23% then it's nitrox and you didn't break the rules????

Any one ever check into the DOT regulations on carrying a pure O2 bottle in your vehicle. I bet that the regulations would require outside markings on the vehicle..... Should dive shops who fill an O2 bottle inspect your vehicle before letting you transport your deco bottle??????