Nitrox needed for wreck dives in this area?

[clearwaterdivers]

Good Point Padiscubapro on the hp seat, sometimes over looked , thats for sure!!

 

[clearwaterdivers]

My shows poilicy is to only fill tanks with Nitrox that are labeled for oxygen service.. I have both banked gases and do PP blending but make No distinction.

In regards to policys, what is the true law, if known, that regaurds the filling of a Nitrox tank with just air? Now, my air is the same all round and is tested to Verify for use with O2. Some shops wont put air only, might contaminate it. (most cases are like me, same air all round. I have in the past done some air only fills, but make darn sure that all Nitrox markings are off and it is obviously marked as air and the diver signs for it as well so that there is no misunderstanding. My fear of doing it all the time for everyone (although not requested much) is the fear of the forgetfull diver in charge. Is there a yeah or neah to air only in a Nitrox tank as a published law of blending or is following ones own Policy still the word?I have been a blender for many years, and may be set in my ways, but new knowledge never hurts.

 

[grouchyturtle]

I STRONGLY recommend any reg that will be used for nitrox servicxe to be dedicated to use with Nitrox or Oxygen compatible air..

Ok, but what about vacation time. A lot of us do most of our diving locally, and use Nitrox or clean air.

But...

A lot of vacation spots don't have Nitrox. No one wants to use rental regs, but who can afford a whole reg set up for just one week or so once or twice a year?

 

[VTernovski]

Ok, but what about vacation time. A lot of us do most of our diving locally, and use Nitrox or clean air.

But...

A lot of vacation spots don't have Nitrox. No one wants to use rental regs, but who can afford a whole reg set up for just one week or so once or twice a year?

I wound't worry about it for standard 32% mixes as long as you are not using silicon when you do the reg maint. Of course for the deco reg is another story, but we are not up to that level yet anyway. The Apeks service kit is the same of O2 clean reg and a regular "up to 40%' regulator.

 

[Charlie99]

I have in the past done some air only fills, but make darn sure that all Nitrox markings are off and it is obviously marked as air and the diver signs for it as well so that there is no misunderstanding. My fear of doing it all the time for everyone (although not requested much) is the fear of the forgetfull diver in charge. Is there a yeah or neah to air only in a Nitrox tank as a published law of blending or is following ones own Policy still the word?I have been a blender for many years, and may be set in my ways, but new knowledge never hurts.

Your policy makes no sense to me. The "prohibition" on air is really just a requirement for a new visual to get back to O2 clean status if there has been a possibility of contamination by air that has too much oil or other hydrocarbons.

Why not just call it EAN21, measure it, tag it, and log it just like any other EAN mix?

Why remove the nitrox markings or O2 clean markings when you have pumped in clean air?

 

[Wreck]

The main sticking point is the idea of having to dedicate a tank(s) to Nitrox--I feel like I will not have a choice to dive air anymore, even on a shallow dive where an expensive Nitrox fill isn't very useful.

Some shops use the same air for regular air fills as they do for mixing the nitrox. It's often called "O2-compatible" air and has to do with how well the air is filtered. As long as you make sure this is the only type of air you put in your tanks, you can put air in your nitrox tanks without worry - they'll (realistically) still be as O2-clean as if you were only filling them with nitrox. Any shop that refuses to do so, I would question their claim that tey are using O2-clean air. Just beware that not all shops produce O2-compatible air for their regular air fills.

 

[Wreck]

In regards to policys, what is the true law

There is no spoon.... errr... law.

f any of you want some decent reading about handling O2 and a lot of the myths associated/perpetuated around it, I'd recommend Vance Harlow's Oxy Hackers Companion book. Even you you're not a home brewer or do-it-yourselfer, there's some good information in that book that will help you understand the what's and why's of O2 practices.

 

[Upwelling]

Since air is effectively EANx21, I don't understand why, for example, EANx32 will cause the reg to combust but EANx21 won't. The reg is being exposed to a large amount of oxygen and in both cases. Can anyone explain this?

 

[grouchyturtle]

Because EAN21 is just air, clean air, but still just air. 21% O2, just like the air you breathe every day. If that had a great risk of combustion, we'd all be in deep **** everyday even without diving.

O2 is what's combustable, so greater O2% = great chance of combustion.

 

[padiscubapro]

Because EAN21 is just air, clean air, but still just air. 21% O2, just like the air you breathe every day. If that had a great risk of combustion, we'd all be in deep **** everyday even without diving.

O2 is what's combustable, so greater O2% = great chance of combustion.

O2 is NOT combustable its an oxidizer.. It makes things that are capable of burning (in reality almost anything burns at some point) burn easier.

Clearwaterdivers,

For people with tanks that have no nitrox markings I do nothing special (other than make sure the manifold/whip pressure is above the tank pressure - I don't want any back feeding of dirty gas) although they are getting oxygen compatible air,
a cylinder thats labeled for either trimix or nitrox gets analyzed and signed out, and labeled with the mix. If you want an "AIr" fill, I'd ask you do you really want 21% (then I'd dump the tank) or just an air top off..
If youd wanted an air top you would get charged for an "air" fill but still make get something like 25%

No Tank Leaves the Shop until labeled and signed for.