Clarification about O2 Clean Tank..

[Hoosier]

I am looking for the Deco or Pony tank that is mainly filled with Nitrox. So, I need to clarify my understanding about O2 clean compatibility.

Even though I am certified Nitrox diver, but I am totally newbie in this world. So, any comments will be appreciated. I plan to get into Adv. Nitrox and Decompression this summer.

I am not sure what is the exact mean and procedure of O2 clean (Viton O-ring and rube) though. As I understood, the new tank from the manufacture is already O2 cleaned. So, it means that the tank can be filled up to 100% O2? Technically, all tanks are ready for “premix” of up to 40% no matter they are O2 cleaned or not? So, O2 clean is required for the partial pressure blending and more than 40% mix. Am I right?

So, if I have the tanks that are filled with the ordinary air (21%), does it mean that I can put the premix (40%) Nitrox on that tank? In the same context, if I buy the used tank, I can put 40% Nitrox in the tank?

What is a typical blending method in most LDS, either partial pressure or premix?


Please let me know if I head for the wong direction.

Thanks in advance,

 

[Doc Intrepid]

I am looking for the Deco or Pony tank that is mainly filled with Nitrox.

I am not sure what is the exact mean and procedure of O2 clean (Viton O-ring and rube) though.

The process involves tumbling the tank while its filled with a cleaning solution and aggregate; glass beads, etc. The tank is then carefully rinsed several times, and dried using a forced air dryer. It is then inspected prior to reassembly. Viton rings are claimed to be less susceptible to degradation and flamability in high O2 environments, and the same is true for Christolube and other O2 compatible lubricants.

As I understood, the new tank from the manufacture is already O2 cleaned. So, it means that the tank can be filled up to 100% O2?

You would be wise to clean it yourself before filling it with 100% O2. Lots of people make lots of claims. But its your *** on the line. How lucky do you feel?

Technically, all tanks are ready for “premix” of up to 40% no matter they are O2 cleaned or not? So, O2 clean is required for the partial pressure blending and more than 40% mix. Am I right?

Technically, yes.

So, if I have the tanks that are filled with the ordinary air (21%), does it mean that I can put the premix (40%) Nitrox on that tank?

NO! Ordinary standard-grade air is not the same as (hyperfiltered) EAN21. If a tank has been filled with ordinary standard-grade air it should be O2 cleaned before it is filled with Nitrox. Trace hydrocarbons could be in the air, and hence in the tank.

In the same context, if I buy the used tank, I can put 40% Nitrox in the tank?

NO! If it's a used tank you have no idea what was in it. Clean it yourself before you fill it.

What is a typical blending method in most LDS, either partial pressure or premix?

Depends. If the shop moves enough nitrox to justify banked premix, then you can fill off their banks. Typically that requires a shop to move a lot of nitrox. Most shops that I frequent partial pressure blend.

Please let me know if I head for the wong direction.

Keep asking questions. Never assume a tank is clean. It doesn't take much to clean them yourself. Learn how. Take a blenders course. Find an LDS that will let you clean your tanks there with their equipment, if you clean some of theirs at the same time. Familiarity often breeds contempt. Don't take O2 for granted or you may regret it.

And finally, as if this lengthy pontification isn't already sufficient, never believe most of what people post on the internet, including me and including here. Check different sources, go back and review this material with your instructor(s), and always emphasize safety.

 

[Dan Gibson]

In our neck of the woods, its pp blending. However, my buddies and I have made the jump to continuous blending our own gas for cave diving and don't waste money on O2 cleaning stages or backgas. A 50% or 100% O2 mix is another story since I'm paranoid about pp blending O2. I only have 4 tanks that see the higher O2 levels. I really wish the shops around here would get a clue about CB nitrox and start banking it. They could drop the price and sell a lot more. The shop I'm with spent some rediculous cash on an automated Annex Supreme (I believe that's the name) back in 2000 and I'll bet they haven't sold 200 nitrox fills to date. It will never pay for itself. If they did bank premix, you wouldn't need to clean the tanks. However, the shop you are near may insist on it anyway

What is a typical blending method in most LDS, either partial pressure or premix?


Please let me know if I head for the wong direction.

Thanks in advance,

 

[Rick Murchison]

I highly recommend you get yourself a copy of "The Oxygen Hacker's Companion" from Airspeed Press.
Read it.
Read it again.
It is excellent.
Rick