Air fills in Nitrox Marked Tanks

[SpecialTest]

I'm new-ish to nitrox diving (certified earlier this year)...

Local dive shop gives me grief when I want air put in a tank with a nitrox wrap, or if I want nitrox in a tank without a nitrox wrap. I always verify the contents and mark/label what the blend is along with MOD, yet it's still a battle with the shop. Am I doing something wrong? Seems silly to "require" a nitrox wrap on nitrox fills, and then simultaneously want none of that if you put air in it. Am I supposed to have dedicated tanks (or remove the wraps and re-install, which sounds downright silly) for this?

Seems pretty logical to me to simply verify the contents, label it accordingly, and then go with that...

 

[Searcaigh]

How does your shop sell the Nitrox?

Do they have a bank of a specified mix or do the do partial pressure mixing?

 

[SpecialTest]

Pulling from pre-mixed banks. A bank of air, a bank of 32%, a bank of 36%. I expected the process to work by telling them what you want, and them putting it in your tank. If what they are putting in is different than what was in there, I would expect them to empty (or close to) the tank beforehand and do a complete fill. It generally works that way unless I want plain air in my nitrox-banded tank, or if I want nitrox in my unmarked (I add a contents sticker, where I write the contents, verify it, date it, add the MOD, and initial it).

I'm aware of the partial pressure mixing issues and O2 cleaning; not a concern here.

 

[Scared Silly]

Just ask for 21% NITROX ... or really as long as the fills are O2 compatible air it really does not mater.

That said, the whole idea of a the NITROX wraps was a way of warning others what is in the cylinder is not air. I prefer this instead:

This Is Not Your Tank

• Scared Silly
• Jan 2, 2011

Stickers from Airspeed Press

 

[Wookie]

Pulling from pre-mixed banks. A bank of air, a bank of 32%, a bank of 36%. I expected the process to work by telling them what you want, and them putting it in your tank. If what they are putting in is different than what was in there, I would expect them to empty (or close to) the tank beforehand and do a complete fill. It generally works that way unless I want plain air in my nitrox-banded tank, or if I want nitrox in my unmarked (I add a contents sticker, where I write the contents, verify it, date it, add the MOD, and initial it).

I'm aware of the partial pressure mixing issues and O2 cleaning; not a concern here.

If it has nitrox in it, do they tell you to make sure it has a tank band on it? Is this a sneaky way to sell you a $23 tank band every time you want to dive nitrox?

I like scared silly’s band personally, but I have my own compressor and maintain my own cylinders. No problems.

 

[AfterDark]

Pulling from pre-mixed banks. A bank of air, a bank of 32%, a bank of 36%. I expected the process to work by telling them what you want, and them putting it in your tank. If what they are putting in is different than what was in there, I would expect them to empty (or close to) the tank beforehand and do a complete fill. It generally works that way unless I want plain air in my nitrox-banded tank, or if I want nitrox in my unmarked (I add a contents sticker, where I write the contents, verify it, date it, add the MOD, and initial it).

I'm aware of the partial pressure mixing issues and O2 cleaning; not a concern here.

If O2 clean is not a concern then you can get your air anywhere. The LDS is just playing stupid because they think you are or they really are.

My LDS does blending so tanks need to be O2 clean, but their air is O2 clean from the nitrox whip so that is what they use to fill O2 clean tanks with 21%. It ain't rocket science.

 

[rhwestfall]

As said upthread, if PPB, it only needs an indication of 02 clean. If banked, almost all times the tank is good to 40%....

You do not "need" a Nitrox label to put other than 21% in it, but should accurately label contents when doing so. There is no "mandatory" method for this...

Then again, their compressor, their rules. To state it is some "Law" is hogwash. If they want to say it is their policy, they can.

Heck, they could mandate that all Nitrox tanks must be pink....

 

[rhwestfall]

Side note: If an 02 cleaned tank, you need to do your 21% fills with 02 compatible (some call it ultra pure") air....

 

[formernuke]

Just ask for 21% NITROX ... or really as long as the fills are O2 compatible air it really does not mater.

That said, the whole idea of a the NITROX wraps was a way of warning others what is in the cylinder is not air. I prefer this instead:

This Is Not Your Tank

• Scared Silly
• Jan 2, 2011

Stickers from Airspeed Press

Sadly airspeed press is no longer, those are my favorite stickers as well.

 

[formernuke]

OP.

As stated above and as you knew the only actual rules are for ppb on nitrox. The rest is just your shop making there own rules.