Nitrox conversion for old US Divers Reg?

[Randy43068]

Randy pretty much hit it but you should contact USD for their opinion. Specifically ask why it can't be used and don't settle for an answer like "because, that is our stand on this." Get specifics.

You're right.

How's the diving in and around NC lately?

 

[DrSteve]

As a chemist I have huge doubts as to the effects of nitrox on equipment. Mostly it is all non-chemists making claims based on zero factual knowledge. But, within the reg is a fluid (my 1st stage is environmentally sealed) and when that is exposed to nitrox it could cause a more rapid degradation, same for the o-rings (and I've managed to make viton o rings disintegrate with some of the stuff I have used).

But...when I get home I will email USD and give them the exact name and serial number of my reg and ask them what can or cannot be done. I doubt I will go beyond 32% nitrox anyway.

 

[Randy43068]

see below

 

[Randy43068]

As a chemist I have huge doubts as to the effects of nitrox on equipment. Mostly it is all non-chemists making claims based on zero factual knowledge. But, within the reg is a fluid (my 1st stage is environmentally sealed) and when that is exposed to nitrox it could cause a more rapid degradation, same for the o-rings (and I've managed to make viton o rings disintegrate with some of the stuff I have used).

But...when I get home I will email USD and give them the exact name and serial number of my reg and ask them what can or cannot be done. I doubt I will go beyond 32% nitrox anyway.

As I mentioned, NITROX may make some of the o'rings fail a little early, but you'll probably never notice because they'll be replaced as part of normal service.

I'm a little confused as to why you would ask the question in the first place, since you're a chemist and should know exactly what will happen with the components in your regulator.

Perhaps you should have posted this question in an academic forum instead of here, where we have no clue to what's going on.

 

[scubamate]

You're right.

How's the diving in and around NC lately?

I'll find out the weekend of the 21st/22nd. The only dive I done here since Nov was last weekend in private lake. Vis was around 25 ft and temp at 35' was 56 deg.

I'm headed to Manatee Springs (Chiefland, FL) Friday to certify a few students there, then Fantasy Lake (Rolesville, NC) with another group of 8 OW, 4 Nitrox and 5 Drysuit students. We'll see how the water is then.

How's Gilboa and White Star. I'm a transplant from Akron in '98 and used to use those quarries and Nelsons quite a bit.

 

[DrSteve]

I'm a little confused as to why you would ask the question in the first place, since you're a chemist and should know exactly what will happen with the components in your regulator.

LOL I may be a chemist, but I am not trained in the inner workings of a regulator. I only have part of the equation. I think a lot of the stuff about nitrox compatibility is just hype, but there is a portion that isn't. I couldn't trust my ex-LDS to tell me what part is hype and what isn't! So I come to my friendly neighbourhood scubaboard where information is more readily shared

 

[Randy43068]

I'm a little confused as to why you would ask the question in the first place, since you're a chemist and should know exactly what will happen with the components in your regulator.

LOL I may be a chemist, but I am not trained in the inner workings of a regulator. I only have part of the equation. I think a lot of the stuff about nitrox compatibility is just hype, but there is a portion that isn't. I couldn't trust my ex-LDS to tell me what part is hype and what isn't! So I come to my friendly neighbourhood scubaboard where information is more readily shared

I'm chuckling now.. please forgive me for being a little thin skinned.

I think that you're right about the LDS and all of the NITROX hype.

 

[MikeC]

Well, Aqualung USA replied to my e-mail.

Hello Michael, back in the mid 90's all the way to the middle of year 2000
USD/Aqualung did not support the use of breathing air with a oxygen content
higher than 23.5% and it was even stated in the owners manuals. This was
primarily because of a lack of adiabatic testing to insure that the regs were
indeed safe to use. Fast forward to July 2000 and Aqualung had finished up
adiabatic testing (Very expensive) on all our current in-line regs and made the
necessary changes to insure their safe use out of the box to EAN 40% when
dedicated. None of the older regs will be tested in this manner and will more
than likely never be approved for anything other than use with air to 23.5%.

Sincerely,

Todd A
Aqualung Repair Dept..

I left off the guys last name and phone number.

 

[groo]

Most recreational diving with EAN doesn't exceed 40% Oxygen. You should be fine with the reg because only your cylinder would be exposed to 100% O2, that is why Viton and oxygen compatible grease is utilized.

If it makes you any more comfortable, I have about 25 dives using Nitrox on my USD Conshelf SE2 and there have been 0 problems to date. I would expect a slightly decreased service life for the internal o-rings and seals due to the higher oxygen content but as you now, the "possibility" of such things are often overstated.

 

[Lead_carrier]

I'm a little confused as to why you would ask the question in the first place, since you're a chemist and should know exactly what will happen with the components in your regulator.

Perhaps you should have posted this question in an academic forum instead of here, where we have no clue to what's going on.

How about taking it a bit easier on him Randy. He's asking because he wants to learn. Something a lot of US should do more of.

The reg is should work fine with EAN <40% with standard service. I have only run into one reg that a manufacturer has given us, in writing, that their reg was not to be used with nitrox.