Titanium vs EAN

[Indian Valley Scuba]

I have a set of Scubapro Ti regs...and they cannot be used with Nitrox. It was stated in the manual and I even checked with Scubapro to confirm this.

And the reason for that is?????

 

[DevonDiver]

Hmmm..... from what I can rememeber (and this was years ago, so I might be wrong) it was more to do with degredation of the regulator than any particular risk of fire/explosion.

 

[NCadiver]

I was considering buying an Atomic T-2 Regulator but i have been hearing some horror stories about some catching fire from people using EAn with these. I was wondering if anyone had some more info on these regs. Are they safe to use wit Nitrox? Does anyone have any experince using these. Thanks for the Help

That was years ago alittle after Atomic started the company, An Atomic told the guy not to use it past 40% but he use 80% or 100% O2 for his deco dive and this pretty blue flame started LOL. I believe this happen in San Diego. Also that’s why they came out with the M2 regulator.

 

[MSilvia]

the issue is that Titanium is a sparking metal, and brass is not. One could theoretically start a fire with a piece of Titanium and a rock, but not with brass.

That's not the issue at all. It has to due with Ti's well known reactivity in high ppO2 environments, not with sparks. If the reg was designed with that in mind, it's entirely possible it wouldn't be a problem, but I personally would prefer a reg made of a metal known NOT to degrade in the presence of high oxygen concentrations if I was going to use it with high O2 mixes at depth. Why spend the extra money on something that's even potentially less suitable for the job?

 

[Hatul]

There is an issue with titanium and high O2, which may not be relevant to normal Nitrox. Several years ago there was an explosion when a titanium reg was turned on on an oxygen tank in San Diego.

Adam

 

[knotical]

The San Diego incident is mentioned in the article here:
http://www.undercurrent.org/UCnow/issues/y2003/UC0103/Nitrox200301.pdf
It does not say what caused the fire. I have not found another source of information on the incident.

 

[MSilvia]

In case anyone is interested, NASA studied the reactivity of Ti with oxygen in various forms and mixtures when evaluating it's appropriateness for use in LOX applications for spacecraft. The findings can be viewed here:
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA398407&Location=U2&doc=GetTRDoc.pdf

I'd like to highlight one paragraph though:

G. Reactions in Gaseous and Oxygen Containing Mixtures

The Stanford Research Institute investigated the reactions of titanium and oxygen-containing atmospheres. A freshly formed titanium surface reacted rapidly with oxygen, and the energy released by this reaction resulted in the ignition of the titanium sample, which then continued to burn until either the metal was consumed, or the supply of oxygen was exhausted. Under static conditions at room temperature, at least 350 psi of 100 percent oxygen was necessary to initiate the reaction, whereas, with 45 percent by volume oxygen, a pressure of 2000 psi was required. Under dynamic conditions, as in the case of a ruptured pressure disc, much less stringent conditions were needed. With pure oxygen, 50 psi pressure would initiate the reaction. Once the reaction began, it would propagate at high pressures with as little as 2 percent oxygen in steam. About 10 percent oxygen was required for propagation at atmosphere pressure.

 

[rstofer]

There's a lot of stuff in that paragraph. At the end, I decided that Titanium regulators are out of the question. Why push it?

Richard

 

[DwayneJ]

Ahhh - A 47 year old paper. If references are going to be quoted, this would be a more appropriate source: Amazon.com: Materials Properties Handbook: Titanium Alloys (06005G): E. W. Collings, Gerhard Welsch: Books

 

[Downing]

You can have the TX updated to the TX2 (I did) and resolved the issue of the phamntom fire issue. They replace $75.00 worth of parts and its an 'X'

Really? I'll have to look into that tomorrow. Thanks for the tip.

I'm surprised Atomic doesn't mention it on their website.

Doesn't the T2x come with some sort of engraving on the first stage? Was that included in the $75 worth of parts?

Too late for Hawaii, though, since I leave on Friday. But I'm headed for the Keys in late August, and I'd love to have the reg updated for that trip.