converting air tanks to EAN

[iluvtheocean]

many of the shops in south florida do partial pressure blending with only a few/some banking it - such as fill express. from what i've been told down here - the big ugly sticker is not mandatory but "recommended" - it's up to the shop's policy whether they will fill nitrox w/o it. and the only info that is really required is current hydro & vis proof and if they don't bank - proof of o2 clean.

i could be wrong on this last bit but just something i heard -- but aren't brand new tanks supposed to be O2 clean from the mfr? so a brand new tank, never filled - should be able to fill nitrox right off?

 

[eponym]

many of the shops in south florida do partial pressure blending with only a few/some banking it - such as fill express. from what i've been told down here - the big ugly sticker is not mandatory but "recommended" - it's up to the shop's policy whether they will fill nitrox w/o it. and the only info that is really required is current hydro & vis proof and if they don't bank - proof of o2 clean.

i could be wrong on this last bit but just something i heard -- but aren't brand new tanks supposed to be O2 clean from the mfr? so a brand new tank, never filled - should be able to fill nitrox right off?

Usual case: That new tank sitting (unfilled) on the showroom floor arrived sans valve, which the shop added. So the one atmosphere of air in that tank contains an unknown quantitiy of hydrocarbons. Not O2-ready.

Best case: the shop performed a full oxygen-compatible cleaning and assembly and no one ever idly opened the valve on the (still-unfilled) tank while it was waiting to be sold. Not likely.

HOWEVER - as pointed out several times in this thread - individual shop policies vary. Some shops will fill with banked nitrox, no questions asked, when you buy a new tank from them.

 

[Wolfie_47]

Usual case: That new tank sitting (unfilled) on the showroom floor arrived sans valve, which the shop added. So the one atmosphere of air in that tank contains an unknown quantitiy of hydrocarbons. Not O2-ready.

I don't get it. At inspection time the inspector opens the tank to inspect it he then screws the valve back on and you still have one atmosphere of air that contains an unknown quantity of hydrocarbons, in your now inspected tank... whats the difference?

 

[windapp]

I don't get it. At inspection time the inspector opens the tank to inspect it he then screws the valve back on and you still have one atmosphere of air that contains an unknown quantity of hydrocarbons, in your now inspected tank... whats the difference?

The tanks do not come oxygen clean from the manufacturer.

 

[eponym]

I don't get it. At inspection time the inspector opens the tank to inspect it he then screws the valve back on and you still have one atmosphere of air that contains an unknown quantity of hydrocarbons, in your now inspected tank... whats the difference?

If you perform the oxygen-compatible cleaning and reassembly of a unit in an oxygen-compatible environment, you can certify it as ready for pure oxygen. Most dive shop service areas are not that environment. Their air is not suitably filtered. The ambient air probably doesn't even meet grade E standards.

This is nit-picking, though. Each shop which performs this service can decide for itself what constitutes a "clean enough" working environment.

 

[rhwestfall]

Each shop which performs this service can decide for itself what constitutes a "clean enough" working environment.

and there you have it.....

 

[NAM001]

I AGREE WITH YOU THAT INSTEAD OF questioning the legimitacy of the sticker they will mandate the eddie, but then again the eddie proof is just a sticker. glad i dive steel.

Wait until they start requiring eddy current testing.

---------- Post added May 13th, 2013 at 03:56 PM ----------

the tanks i see sy cleaned for up to 40% so technally ppb is still an issue.

many of the shops in south florida do partial pressure blending with only a few/some banking it - such as fill express. from what i've been told down here - the big ugly sticker is not mandatory but "recommended" - it's up to the shop's policy whether they will fill nitrox w/o it. and the only info that is really required is current hydro & vis proof and if they don't bank - proof of o2 clean.

i could be wrong on this last bit but just something i heard -- but aren't brand new tanks supposed to be O2 clean from the mfr? so a brand new tank, never filled - should be able to fill nitrox right off?

---------- Post added May 13th, 2013 at 03:57 PM ----------

Its good that common sence prevails somewhere

Usual case: That new tank sitting (unfilled) on the showroom floor arrived sans valve, which the shop added. So the one atmosphere of air in that tank contains an unknown quantitiy of hydrocarbons. Not O2-ready.

Best case: the shop performed a full oxygen-compatible cleaning and assembly and no one ever idly opened the valve on the (still-unfilled) tank while it was waiting to be sold. Not likely.

HOWEVER - as pointed out several times in this thread - individual shop policies vary. Some shops will fill with banked nitrox, no questions asked, when you buy a new tank from them.

---------- Post added May 13th, 2013 at 03:59 PM ----------

the vis process does not distinguish between new and old tanks. so the tank could have been just hydro'd and i dont want to think what oil and crap is in that water.

I don't get it. At inspection time the inspector opens the tank to inspect it he then screws the valve back on and you still have one atmosphere of air that contains an unknown quantity of hydrocarbons, in your now inspected tank... whats the difference?

 

[SCUBA_Phil]

The irony in this thread is that the tank does not matter as much as the valve, but I never hear "Is your valve O2 clean". The real kicker was when I was diving at the Catalina dive park and they said they could not fill my tank with air because it was nitrox ready. Over the years, I just got frustrated with the shops and then they raised the price of He. At this point, i started to do my own fills and never looked back!

 

[Abdullah]

If you perform the oxygen-compatible cleaning and reassembly of a unit in an oxygen-compatible environment, you can certify it as ready for pure oxygen. Most dive shop service areas are not that environment. Their air is not suitably filtered. The ambient air probably doesn't even meet grade E standards.

This is nit-picking, though. Each shop which performs this service can decide for itself what constitutes a "clean enough" working environment.

I don't think this is correct. The room air isn't really relevant to the O2 cleaning standard (barring suspended oil mists, which cause you other problems).

If the manufacturer claims the tank is O2 clean, it will come with a shipping plug that protects the threads and interior. If an O2 clean valve and O2 compatible O-ring are installed, the tank is O2 clean and ready for PP blending. If a tank has been O2 cleaned, and is unused, it's still O2 clean.

What pollutes the tank is substandard (less than E+) air fills. It only takes one such fill and your tank is no longer O2 clean. This is common in the middle east.

 

[nitroxfox]

Those area your shop regulations. They do not pertain to all other places in the world.

My tanks are O2 cleaned, and I myself, as a certified tank inspector, have slapped an O2 clean sticker with my inspector number on it each year. It does not have an ANDI reg number on it--it has my PSI number on it. It has never been turned down for filling anywhere I have taken it. It sounds like your shop is looking for a little extra cash.

Actually,

The DOT does not recognize the sticker of any training agency. If you want to inspect cylinders, you need approval from the DOT. Eddy current is only needed on 6351 T6 aluminum alloy at the time of requalification per 49CFR 180.209. Anyone re-qualifying, re-conditioning, repairing, etc a cylinder needs DOT approval in the USA. Annual visual inspections are not needed to satisfy DOT requirements but they are GOOD practice. They are the recommendations of CGA Pamphlet P9 and are adopted by the recreational dive industry, but they are not LAW and required by the DOT. If you are removing contaminants and certifying that the cylinder is good for O2 use, you should have approval as it is considered reconditioning. If you rebuild valves and change o-rings, etc on the pressure vessel, it is considered a repair and you should have approval.

Furthermore, if you want to learn how to clean a cylinder properly, I suggest getting instruction from a certified approved DOT facility or getting training at Wendell Hull and Associates in New Mexico, USA. I was recommended to them by NAVSEA as it is who the US Navy uses. They are also recognized for training by the DOT. Bear in mind that upon completion of training, one needs to apply to the DOT for approval to inspect and recertify cylinders. It is similar to going to Captain's School for training as a Captain in the USA. You get a diploma from Captain's School upon completion of their course, but you are not approved by the Coast Guard as a Captain until you meet all of the application and testing requirements and are issued your Merchant Mariner Credential. The certificate you get from any training agency is not recognized as approval by the DOT. It only certifies that you received training from someone, however, this does not certify approval requirements.

Here is the link to Wendell Hull:
Forensic Engineering & Oxygen Safety Experts - Wendell Hull & Associates, Inc.

It is a lot of information, I know, but trust me, once you start to get the real picture, you will be surprised. At least here in the USA!!!!

---------- Post added May 19th, 2013 at 04:59 PM ----------

Sorry,

It is actually CGA P-5 not P-9 that is the Suggestions for the Care of High Pressure Air Cylinders for Underwater Breathing. My mistake!!