Do Nitrox dedicated cylinders need to be O2 cleaned every year?

[RSdiver]

There is no such thing as cleaning a cylinder for 22% to 40% or cleaning a cylinder for mixes above 40%. It's either cleaned or it's not. What the store is talking about is that technically a cylinder doesn't need to be cleaned for pre mix/banked Nitrox mixes 40% or less because oxygen above 40% never touches the tank. If a shop does partial pressure blending then pure, 100%, O2 is added to the tank and then specially filtered air is added on top to get the desired mix. In this case the tank and valve must be cleaned to remove any contaminants. If the shop you previously used banked pre mix they most likely didn't clean the tank as it wasn't necessary and the new shop, using the partial pressure method of blending would need to clean the tank before they could fill it.

Let me clarify.
The tank was sent for the annual VIP not for cleaning, so the 22-40% VIP vs a VIP valid for above 40% was not to be confused regarding cleaning.
By VIP'ing for 22-40% Pacfic Wilderness allows that tank to be used only for pre-mixed Nitrox and NEVER blended by Partial Pressure. What they didn't tell me was that they never carry pre-Mix, but to their credit the did point me to a competitor which does have pre-mix.

Although the tank has always been to dedicated Nitrox, the tank it was never filled by Partial blending; the shop "Any Water Sports" in San Jose has a bank of Pre-mixed Nitrox.

 

[simbrooks]

Different question, why do you need nitrox in a pony? If you have nitrox in your main tanks, the pony should be for CYA out of air scenarios and essentially enough to ascend on, it will hardly make any difference to your N2 loading as you are only using it a short time and ascending whilst doing that. Beyond this, my main tanks are going to be up for their first annual in 6 months, having not done this before i was wondering if they just needed a VIP or O2 as well, it seems that O2 might be good every other year or if something goes awry with them just to get rid of any contaminants that have got in there.

 

[Padipro]

I always carried Nitrox in my pony on the assumption that my OOA situation might be do to an emergency that kept me at depth longer then I wanted causing me to use up my gas supply and bust the NDL for that depth. Now I have a deco obligation and I'd rather be sucking Nitrox then air if this were the case. Also, in that same situtation, unless you have a computer capable of doing gas switching during the dive you have switched to a gas with a higher nitrogen content then the gas your computer was programed for and it has no way of calculating that deco obligation correctly because it's still assuming that you're breathing the original gas not air.

 

[RPanick]

The question still didn't get answered, how often should O2 clean equipment be recleaned? In theory if you are getting fills from shops providing clean air, it shouldn't need to be done again, or at least not very often. But how does the shop know that. Lets face it the Nitrox stickers are for the shops protection, not just yours.

One other thing that is part of O2 clean is to make sure all of the O rings are O2 safe, and even these need to be replaced periodically because they will degrade with exposure to O2. Or so I'm told.

I'll probably find out myself in a month or two when I take them in for the anual VIP, and maybe cleaning.

Bob

 

[Brian Gilpin]

The question still didn't get answered, how often should O2 clean equipment be recleaned? In theory if you are getting fills from shops providing clean air, it shouldn't need to be done again, or at least not very often. But how does the shop know that. Lets face it the Nitrox stickers are for the shops protection, not just yours.

One other thing that is part of O2 clean is to make sure all of the O rings are O2 safe, and even these need to be replaced periodically because they will degrade with exposure to O2. Or so I'm told.

I'll probably find out myself in a month or two when I take them in for the anual VIP, and maybe cleaning.

Bob

The answer is once a year when you get it vizzed.After all you already have it apart and will probably be replacing rings etc.However the first time you get a fill of air not up to O2 clean standards your tank will need to be redone. As stated above however you can avoid the whole issue by not using shops that can only do partial pressure fills. I keep an extra tank for when I am on a boat or other situation where the fills will not be sufficiently filtered to keep the tanks o2 clean.

 

[gjmmotors]

If you are sure that your tanks have only been filled with clean air, then you shouldnt have to clean them every year. I clean mine after a hydro, or a "dirty fill".You can do a search for what type of orings to use. Paying to clean one tank a year isnt bad, paying to have 10 or 15 tanks cleaned a year is bad. Get fills from a tested and reputable air source.
-g mount

 

[padiscubapro]

The question still didn't get answered, how often should O2 clean equipment be recleaned? In theory if you are getting fills from shops providing clean air, it shouldn't need to be done again, or at least not very often. But how does the shop know that. Lets face it the Nitrox stickers are for the shops protection, not just yours.

One other thing that is part of O2 clean is to make sure all of the O rings are O2 safe, and even these need to be replaced periodically because they will degrade with exposure to O2. Or so I'm told.

I'll probably find out myself in a month or two when I take them in for the anual VIP, and maybe cleaning.

Bob

If only oxygen compatible air has been put in the tanks, it shouldn't need a recleaning but as soon as its been filled by an questionable source it has to be re cleaned.

A shop can get a reasonable idea if the tank is most likely still clean by examining the valve for oil residue and examining both the tank and valve with a black light.. This will highlight natural oils, but not all synthetics...


A dirty valve is actually a higher risk than some contaminates in the tank.. I rebuild/clean all my valves EVERY year..