Oxygen Clean Tank

[FishDiver]

Here in Australia we are compelled to hydro tanks every 12 months. Plus, tanks have to be oxy cleaned after every hydro to maintain Nitrox certification.

I understand in the US that tanks require hydros every five years. How often are they oxy cleaned? Is it every five years or more frequently?

 

[dl348]

Here in Australia we are compelled to hydro tanks every 12 months. Plus, tanks have to be oxy cleaned after every hydro to maintain Nitrox certification.

I understand in the US that tanks require hydros every five years. How often are they oxy cleaned? Is it every five years or more frequently?

Here, scuba tanks must have a VIP/VCI every 12 months. They should also be oxygen cleaned every 12 months if you want to use them for Nitrox. Hydros are done every 5 years.

 

[H2Andy]

yeah, visual every year, hydro every five

as to o2 clean, you don't have to have the tank o2 cleaned at all, but as dl348 says, you do it every year if you're going to be using Nitrox (you don't have to, but it saves hassles at the shop)

 

[riguerin]

Yes - hydro every 5 years, viz every year as well as cleaning for O2 service if you're going to get fills using a method that will expose your tanks to O2 greater than 40% (i.e. partial pressure blending).

 

[mike_s]

As the others say, 5 years on hydro as requirement by DOT (Department of Transportation).

However, there is no O2 requirement for Nitrox. Only if you do fills over 40% or where they do "partial pressure blending", which is where they start by filling X amount of 100% o2 into your tank and then completing the fill with o2 clean grade air. I actually don't know if there is a legal requirement for this to be O2 clean, but if it's not, then the Darwin Award is usually given in the end result.

Some folks fill nitrox into non-cleaned tanks, but it's always 40% or less "pre mixed" or "banked" nitrox fills.

Just like there is not a legal requirement for Visual inspection here every year. But all shops require it before filling a tank. Their requirement is basically because that's the way they were taught or their training agencies suggest it. It's smart practice regardless.

 

[FishDiver]

Ok, I am confused. Or maybe its the situation that is confusing.

When I return to the US and buy new tanks that state they are "Nitrox ready" I assume I get a certain grace period before I have to have them cleaned again. Are you all saying there is no federal law on this and that it is up to each individual LDS to allow a nitrox fill or not?

This is not an idle question, I will be moving back in the next year and buying a new set of tanks.

 

[H2Andy]

Are you all saying there is no federal law on this and that it is up to each individual LDS to allow a nitrox fill or not?

yeah...

but if the tank is o2 cleaned for that year, you'll have no trouble

however, unless there's a sticker on the tank saying that, the guys at XYZ shop aren't going to take your word for it that your tank is "Nitrox ready"

... and will then gladly sell you an O2 cleaning for $29.99 even though they are banking Nitrox and you don't need the tank cleaned



but, unfortunately, most shops don't O2 clean at the shop, so you'll have to wait until their o2 clearner comes along to pick up tanks, takes them to the shop, and returns in a week or so to deliver your tank!

ain't life grand?

 

[Warren_L]

Ok, I am confused. Or maybe its the situation that is confusing.

When I return to the US and buy new tanks that state they are "Nitrox ready" I assume I get a certain grace period before I have to have them cleaned again. Are you all saying there is no federal law on this and that it is up to each individual LDS to allow a nitrox fill or not?

This is not an idle question, I will be moving back in the next year and buying a new set of tanks.

You're confused and rightly so. I really don't know why tanks are being sold indicated as "nitrox ready". As far as I'm concerned, that's pretty meaningless. A tank can be used for nitrox without being oxygen cleaned, and yet, it is still "nitrox ready". This does not mean you can get fills just anywhere. It has to be from a source that does not require pure oxygen. The problem is, partial pressure blending using pure oxygen is probably far more common and available. For example, filling EANx32 from a banked source does not require oxygen cleaning of the tank.

What you need to look for is the sticker that indicates the tank and valve are cleaned for oxygen service. This means that you can fill the tank with nitrox using methods that employ pure oxygen.

 

[riguerin]

Ok, I am confused. Or maybe its the situation that is confusing.

When I return to the US and buy new tanks that state they are "Nitrox ready" I assume I get a certain grace period before I have to have them cleaned again. Are you all saying there is no federal law on this and that it is up to each individual LDS to allow a nitrox fill or not?

This is not an idle question, I will be moving back in the next year and buying a new set of tanks.

If you buy a new tank that is "Nitrox Ready" it is good to go right out of the box for premixed blends upto 40%. No real need to do anything else to prep tanks. If you plan to use a source that only does partial pressure blending only, however, then you will need to send it out to get cleaned for O2 service.

The more confusing issue that I've found locally is tank identifications. Some places that provide premixed blends only don't require any thing at all; some expect viz sticker or similar placard to identify tanks as "Nitrox Ready" or "O2 Service Clean"; some also expect the tank to be identified as a dedicated Nitrox tank (i.e. big green/yellow tank bands).

 

[riguerin]

There's a good explanation on the differences between "Nitrox Ready" and "O2 Service Clean" on the Fill Express FAQ site