Thermo valves and 40% O2 max??

[seeker242]

So apparently, Thermo valves now come with a notice that says "Maximum 40% O2". Is this a legitimate concern? Does this mean thermo valves can't ever be used on a deco bottle? Or is it just legal BS from the company's lawyers? Is there something special about thermo valves that make them intrinsically unsafe for 40+% O2, even when they are properly O2 cleaned?

 

[teknitroxdiver]

Largely lawyer BS, though also a good reminder to be smart about it if you choose to use any equipment for oxygen service.

About "40% MAX OXYGEN" Disclaimers | Dive Gear Express®

 

[Tug]

+1 on the article from DGX

I mainly put it in the lawyer BS category and wouldn't stress having to put a marked valve on deco bottle. I know some shops that have no problem filling marked deco bottles as well but it's best to check with your shop. Worst comes to worst, there are other valves out there that you could use if the shop complains.

 

[Wookie]

There is no such thing as a seat in a scuba valve that is O2 compatible. Thermo doesn't make one, Sherwood doesn't make one, OMS, Blue Steel, and Dive Rite don't make one. I have burned more than one seat while boosting/transfilling/filling oxygen cylinders. Doing so renders the cylinder unusable until drained, flushed, cleaned, and the valve rebuilt. So, the statement from Thermo covers their butt, because they know you're going to use it for oxygen service anyway.

 

[fmerkel]

The seat is the weak point, assuming you are using Viton O-rings? Some kind of nylon?

 

[teknitroxdiver]

The seat is the weak point, assuming you are using Viton O-rings? Some kind of nylon?

Teflon-coated nylon.

 

[boulderjohn]

When I renewed my tank inspector certification in January, the instructional materials said no scuba cylinder valve could be made safe for O2 service because of the sharp angles in the flow of gas through the valve. That puts all inspectors in a bind when they put an O2 clean sticker on a tank, since we now know that a scuba tank cannot be made safe for O2 service, even when we are putting our inspector numbers on tanks we certify for O2 service.

I ran into this first a couple of years ago when we bought some new Thermo valves and saw the wording. We called Thermo and the person with whom we spoke confirmed it. On the other hand, you could almost hear him winking as he spoke.

 

[Wookie]

When I renewed my tank inspector certification in January, the instructional materials said no scuba cylinder valve could be made safe for O2 service because of the sharp angles in the flow of gas through the valve. That puts a all inspectors in a bind when they put an O2 clean sticker on a tank, since they now know that a scuba tank cannot be made safe for O2 service, even when we are putting our inspector numbers on tanks we certify for O2 service.

I ran into this first a couple of years ago when we bought some new Thermo valves and saw the wording. We called Thermo and the person with whom we spoke confirmed it. On the other hand, you could almost hear him winking as he spoke.

Ah, yes, but O2 clean and certified for O2 service is 2 different things, and while splitting hairs, I don't see that a cylinder inspector certifying a cylinder as O2 clean is a big deal, certifying it for O2 service is.

 

[seeker242]

The seat is the weak point, assuming you are using Viton O-rings? Some kind of nylon?

None right now. I'm just shopping for a future tech class and wondering if I should purchase a thermo valve or not.

 

[Wookie]

None right now. I'm just shopping for a future tech class and wondering if I should purchase a thermo valve or not.

There is no better, or worse choice.