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DetectorGuy · 02-11-2010, 09:48 PM,

All of the posts on O2 cleaning of tanks are from 2003 or 2002 and I wanted some current feedback. I just picked up a couple of high pressure Worthington 120 CF tanks. They came cleaned of fluorocarbons to accept up to 40% O2 These are new with plugs in the tanks and 3445 PSI valves in boxes. I plan on using these primarily as nitrox tanks at 32% or 36%, but there will probably be times that they will have 21% "normox". I realize with out O2 cleaning that I will be stuck to using only banked 32%, or 36% nitrox (or 21% air). Is this a big deal if I don't get them O2 cleaned knowing I will be saddled to banked gas? Are there a lot of shops that only offer partial pressure blending or is pre-blended nitrox the norm? I also have some of my older 80 CF alum's that I would like to use for 32% or 36% too. I assume these would not need to be cleaned either (given the same use) even though they have had god knows what quality of air in them in the past.

Shooter · 02-12-2010, 08:08 AM,

I doubt that you would ever need anything higher than 36% in your 120s. I would recommend using one of your aluminum 80s for a higher mix. Are you going to have them ready to go by the 20th?

mattd · 02-12-2010, 08:11 AM,

I don't think he is asking about needing a higher mix but whether he needs to get them cleaned so he can partial blend. That all depends on where you are diving. A couple shops in town bank it and there will be no problem. Up in Brainard, for some reason they have banks but partial fill anyway. I can't quite figure that out.

To make sure you won't have a problem, get them cleaned. Then, just be sure that air you buy is hyper filtered or you'll have to get them cleaned again.

arcFlash · 02-12-2010, 12:41 PM,

I have one that is nitrox without cleaning. I haven't had an issue. I have 2 clean and 8 normal (I think)

The only thing I can think of is if you want a partial 32 filled with an end EAN36 my shop does the blend in the tank.
Do you really care if it's 32 or 36? The difference is likely too small to be worth much even at long times. Your better off just using 40cf with 50+ and planning software if 32 isn't going to do it before NDL hit you.

I don't regret my single 80 not being clean. I get it filled without regard for the shops 02 standard but it's labeled so I can if it's available.

DetectorGuy · 02-12-2010, 02:38 PM,

I probably won't have them ready for the 20th but that is going to be so shallow that I can get by on my other tanks. In the long run I think I will label up the 2 hp120 steels and 5 alum 80's. I will keep the other 7 tanks as "air only" for now. So Nate if you happen to know someone in the sign business that can print 7 nitrox stickers for 7 1/4" diameter tanks,I would gladly pay that guy for his artwork.

DetectorGuy · 02-12-2010, 06:31 PM,

I should have my new light sabre's battery cycled and charged by the 20th for sure... 15 watts of blinding madness...

aknelsonone · (This post was last modified: 02-13-2010, 06:10 PM by aknelsonone.)

I would recommend to buy cleaned tanks and then keep them clean.
It is not only hydrocabonates that needs to be removed it is also rust and other
foreign materials. I usually get the tanks cleaned after they are hydro tested.

The reason is the way the shop fill the tanks. The shops will fill first with O2 then add the air for Nitrox partial pressure blending. This is the common way to get by with simple equipment.

If a combustion is happend during the fill process it might not be noticed.
However your tank will contain the combustion gasses and they will be the hazard.
I can just say O2 is a Hazardous material I had a combustion inside a leaky O2 cleaned DIN fitting!
The leak was the problem the metal got nicely discolored shaped like a flame.

Yes we can say at the pressure for partial blending most likely there will be nothing going wrong. And yes banked Nitrox 36 will not be a problem.
However the "what if " makes us cleaning the tanks. If the tanks were not cleaned do not label them as such you endanger others. There are a couple stores offering cleaning services.

Send PM to get more Info about Oxygen if you are interested.

Andreas

arcFlash · (This post was last modified: 02-14-2010, 08:32 PM by arcFlash.)

"If the tanks were not cleaned do not label them as such"

Just so all the new kids don't get confused, "O2 Cleaned" and "Nitrox" are not interchangeable. You may "Nitrox" label any tank regardless of cleaning. "O2 Clean" is only important for shops to tell them it's safe to use O2 on that tank. "Nitrox" is for you and everyone else so they know to analyze before use and that "it's not air"

I have 3 Nitrox labeled tanks, 2 are also O2 clean. I use the Nitrox labled (not cleaned) tank when I want nitrox but I also need fills that are not from 02 clean compressors. The issue is, if I get a fill from a source that's NOT clean, my O2 clean tank is NOT clean and I need to remove that label immediately.

I enjoy the flexibility provided by the Nitrox label but without the O2 headaches.

grumpie · 02-14-2010, 08:58 PM,

not many shops do P/P filling any more.

leadking · 02-14-2010, 09:09 PM,

All Worthington's come O[sub]2[/sub] clean. Thermo valves were are also O[sub]2[/sub] clean. Because of liability issues the old Thermo (vs new Thermo owned by XS and made in Taiwan of which I can not comment on) would only state 40% pre-blend. If these are used tanks and valves, a oxygen cleaning would be required. If new, you can not get them cleaner!!!