VIP on two steel 120's gone bad!!!

[Randy43068]

I'm not so concerned with some flash rust as I am with clean valves.

 

[DCBC]

Hummm, interesting comment from a PADI MSDT... You can train for Nitrox along with Open Water and since it's not an 'in water' skill, it doesn't add substantially to the skills mastery or to the information overload. IMHO, this is well within the bounds of practicality even from dive one.

Again, an interesting comment. If a black light doesn’t show evidence of contamination by petroleum products, no re-cleaning would be necessary to re-certify a tank as “O2 Clean”.

Just my 2 cents. Be safe and have fun in the water! Bruce

First of all I don't train Nitrox until after Advanced Air. Minimum requirements are below my requirements.

As to evidence of contamination, I did not comment on this. An annual tumble of non-air cylinders is a commercial diving practice.

 

[Garth]

wow, i think i stirred up some trouble.
update I have 25 dives, not that it matters because I know I'm new. I am PADI certified for open and advanced open water diving. I will be getting certified in Nitrox shortley (within a month or so) so i wanted my tanks O2 cleaned for that reason. I will be diving singles for at least another year.
I picked up the tanks and I'm not mad at all anymore. The shop explained each piece they replaced including O rings and the seat for the valves. The wanding for the two tanks were 10 dollars each. not bad in my mind now knowing how long it took.
My tanks are clean and free of rust with completely rebuilt valves.

And for the gentleman who wondered why I have the equipment I have being as new as I am. I would like to ask him to think about when he first started diving and how overwhelming the feeling was. I would dive everyday if I could. Its in my head when I drive to work and when i return. Right now i work in a Trauma unit about 60 hours a week. makes it difficult.

thank you all for responded, and I can't wait to tell you how the tanks did in my local quarry

 

[SparticleBrane]

I honestly can't believe someone is saying that they won't teach nitrox until "advanced air".

At the end of my open water class I had an nitrox card.

 

[JDMerk]

ooops

 

[JDMerk]

Did you train at NCSU? I think they are rolling out the OW EAN combo right now for their new students...they switch it up a bit every now and then.

 

[halocline]

Garth, you have absolutely nothing to worry about or apologize for with regards to getting nitrox training very early in your OW experience, and that's also true for owning the larger tanks. It's too bad more new divers don't take the initiative to advance their diving like you evidently are. In fact, if you are using big tanks to increase your depth/time, it's a very good thing that you're using nitrox. Although there is no documented proof (through statistical study) that using nitrox increases diver safety, there is a generally accepted assumption that it does reduce the risk of DCS when used conservatively. About the only way it could increase danger would be through disregarding the MOD or not knowing the correct O2 percentage in your fill.

I'd be cautious about this "wanding" bit. It's almost certainly similar to the old chain whips, except maybe with an abrasive whip. Get the tanks tumbled, that's a proven way of safely and effectively removing rust and resurfacing the inside of the tanks. It should be about $7-10/tank at a hydro facility to have that done. Tanks are tumbled by spinning them, fairly slowly, on their sides while partially filled with abrasive pellets. It results in a very even and clean surface.

 

[DA Aquamaster]

DA,

How often do tanks that have been reasonably well cared for need tumbling? I know people are more picky today for various reasons (O2 clean etc) than we were years ago when we accepted flash rust as normal. Also, if I'm remembering correctly, it was pretty standard to get a hydro done if a tumble was required. Is that still the case?

Cheers,

Couv

It depends on the quality of the gas that has been in them, number of fills, etc, and how picky you are with regard to flash rust, but most steel tanks that are well cared for will go 5-10 years before needing to be tumbled.

Again, an interesting comment. If a black light doesn’t show evidence of contamination by petroleum products, no re-cleaning would be necessary to re-certify a tank as “O2 Clean”.

I've changed my opinion on black light inspection over time. Whether a contaminant is visible under black light depends on the contaminant and on the particular wave lenght of the light. Seeing something under a black light means somethign is there, not seeing anything with a black light just tells you that you couldn't see anything with the black light, not that the tank is clean.

I can understand some commercial operations may want tanks tumbled annually. But being tumbled and being 02clean are two different things. Tumbling media is almost impossible to clean and what ever contaminants are on it, are potentially in the tank, so it becomes a two stage process. Tumble the tank to remove rust and any buildup up of contaminants etc, then O2 clean the tank to remove any contamination left after the tumble or caused by the tumbling.

This second phase will involve rinsing the tank, then tumbling it with a suitable cleaning solution and then rinsing and either tumbling and rinsing again with an O2 compatible rust inhibitor, or skipping the rust inhibitor and quickly drying the tank to prevent any flash rust formation.

-----

Contaminants in a tank are just fuel and without an ignition source you could put a quart of 10W-40 in the tank and not get a fire. It is the valve that is much more problematic as scuba valves are not designed for or well suited to O2 service - they pressurize very rapidly and they tend to have lots of twists, turns and sharp corners and edges in the flow path. All of the above can create hot spots, can increase the chance of a spark due to an entrained particle, or create heating through compression within the valve.

So in my opinion, a tank has to be fairly dirty to be a hazard while a valve can never be clean enough. That said, I am also concerened with particle entrainment due to the valve issue, so my tanks get tumbled and recleaned if there is any rust in them at all.