Are viton o-rings really necessary?

[halocline]

I
If you wish to believe that all the dynamic seals in modern regulators are made with nitrile...reality is not going to get in your way.

I didn't say that, just that only a very few use viton.

I would certainly use viton on the tank neck and valve o-rings for a 100% O2 cylinder, and for a regulator used primarily with 100% O2. But I would not panic about using a reg with unknown o-rings (either EPDM or nitrile) with recreational nitrox.

Your test of storing o-rings in a pressurized O2 environment is only remotely similar to the exposure a tank neck o-ring would with a 100% O2 bottle.

 

[redacted]

I DO know that maintenance is a critical element, and I make very sure that my tank valves and regulators are serviced annually.

How do you know that annual maintenance is critical? With 4 tanks in use for 10 years each, I have serviced one valve in that time (due to a leak from the valve stem o-ring).
And my 8 regulators that my wife and I use get serviced about once every 5 years, typically due to an incipient failure mode of IP creep.

Such extended service intervals make me favor viton and EPDM o-rings due to their longer shelf life.

 

[fppf]

If the only way to advance knowledge were FORMAL EDUCATION, the earth would still be flat.

Ah, but just think how much easier it would have been to educate and advance. If only people that did not understand the science of why the earth was really round would have kept quiet. Rather then constantly spreading untrue information based on opinion.

Not saying SB is full of BS. Just saying reader beware. And I'm sure everyone from a respected field in there profession has seen a post and just scratched there heads with a "what??" "Really??"

 

[rhino3201]

I agree with Rhone Man, SB is awesome! I admit to pushing my luck. I have had my regs. for longer than I care to admit publicly and have NEVER replaced the O rings. Jusat dumb luck nothing has happened. At any rate I see the light and am sending mine off to be rebuilt this week. I recently got my NoTrox cert. and have been contemplating using the Viton O's. My instructor stated the biggest difference was when you got over 36%. 32-36 didn't matter a lot. By the way if any one is wondering, I have Sherwood regs. The Oasis. I bought them in '96! Like I said, dumb luck. Never had a problem out of them.

 

[Mike Boswell]

How do you know that annual maintenance is critical? With 4 tanks in use for 10 years each, I have serviced one valve in that time (due to a leak from the valve stem o-ring).
And my 8 regulators that my wife and I use get serviced about once every 5 years, typically due to an incipient failure mode of IP creep.

Such extended service intervals make me favor viton and EPDM o-rings due to their longer shelf life.

I said I know that "maintenance is a critical element", and I added that I do it annually.

By "tank valve" I meant the yoke o-ring, not the entire valve.

The manufacturers of my regulators recommend annual service. That is how I know.

 

[Bubbletrubble]

I said I know that "maintenance is a critical element", and I added that I do it annually.

By "tank valve" I meant the yoke o-ring, not the entire valve.

The manufacturers of my regulators recommend annual service. That is how I know.

@Mike Boswell: There's a very good chance that you're overhauling your regs more often than you really need to. If maintaining the manufacturer's warranty is important to you, then you are doing the right thing by servicing it at the manufacturer-recommended interval.

I'm just going to state the obvious: the manufacturer is probably putting forth an overly conservative estimate of how long the o-rings in a reg might last. Having this policy in place makes sense from the point of view of the manufacturer because: (1) it might decrease the possibility of reg failure and (2) it provides dealers/reg service shops an enhanced revenue stream.

I believe that awap subscribes to the philosophy that regs should be serviced when they show signs of incipient failure, e.g., excessive IP creep. This approach makes a lot of sense if you consider that, whenever someone overhauls your reg, it increases the possibility that something might be put back or adjusted incorrectly. Essentially, a diver goes from having a functioning reg to one that doesn't work. On a personal note, I have been the victim of an "underhaul" on more than one occasion. That was enough to convince me to overhaul regs on an as-needed basis.

 

[fppf]

This whole idea of waiting until your reg fails before fixing it is insane. Do you wait for your brakes to fail before you fix those as well? Do you want the airlines to wait until the engines flame out before doing service on those? FYI, at set intervals they tear apart the whole aircraft, even when "nothing is wrong with it".

Time and time again we have learned in industry that it is far easier, safer, and CHEAPER to do preventative maintenance then it is to do reactive maintenance.

Its easier because if you service your reg more often and clean it you wont give the corrosion time to set in. Parts don't get locked together, pitted, and generally screwed up. Its much nicer to choose when you want your gear to be out of service for a day or so then to have it tell you when its out of service at any random time.

Its safer because your much less likely to have a reg fail on a dive. And if a reg has an issue from the service its self it should show up on the bench. If it does not show up in bench testing the bench testing is inadequate. A simple checkout dive and your good to go.

Its cheaper because as mentioned earlier you clean it more often and are less likely to need to replace parts from corrosion or lack of lubrication. And if your reg fails on week long dive trip in the middle of the pacific, well then having it serviced just turned a whole lot cheaper.

 

[halocline]

I don't think anyone is suggesting that you wait until your reg fails to service it. To stay with your brake analogy, when do you service your brakes? Every X miles, or when they show signs of wear upon inspection? It's the same with regulators. A little IP creep, a small leak here and there, or maybe simply enough time/dives so that you would feel better servicing it. But simply taking the manufacturer's recommendation for annual service is excessive IME, and given the lack of qualifications required to be a "professional" service tech, is undoubtedly more likely to result in a failure on a dive trip that simply inspecting regularly and servicing when indicated.

The manufactures are looking out for their dealers, and themselves to an extent with this absurd 'every year or else' service policy. But not for recreational divers.

A huge problem with the whole safety and maintenance issue as prescribed by the dive gear industry is that there are no licenses, no exams, no qualifications for professionally servicing regulators, other than the one-or-two-day no fail seminars offered by the manufacturers. If regulator failure was truly life-threatening, you can bet that you'd need a license with peer reviewed exams to work on them.

 

[redacted]

This whole idea of waiting until your reg fails before fixing it is insane. Do you wait for your brakes to fail before you fix those as well? Do you want the airlines to wait until the engines flame out before doing service on those? FYI, at set intervals they tear apart the whole aircraft, even when "nothing is wrong with it".

What is insane is having someone service your completely functional regulator annually and subjecting it to the introduction of service errors and defective parts which can result in fairly serious problems just to prevent your regulator performance from degrading or to prevent the inconvenience of a small leak.

A regulator is a lot more like a kitchen faucet than a passenger airliner. Do you wait for your kitchen faucet to develop a leak before you replace the seals?

If a diver is unwilling to spend $25 for an IP gauge and learn to do frequent inspections of their regulator, along with good care and cleaning; then they may have little choice but to follow the manufacturers' recommendations for keep their LDSs in business. But, the diver does have options.

 

[nhwinnidiver]

Is there even REALLY a difference between viton o-rings and the generic, your gear will blow up if them come in contact with 02 o-rings? Or is that just yet another way for them to overcharge you for something that's not really necessary?

Looking at them side by side I can't even see a difference. If I was to dump all my BAD o-rings in the pack with the vitons, they'd get mixed up, and I'd have no idea which ones I was using. S**t is there even such a thing as vitons or did they just make up a word and put in on the package. How do do I even know that pack of vitons are even vitons other than just the magic word on the box...considering they look the same as the other ones?

I appologize up front for what seems like a long winded answer.
For the last eight years I worked in advanced development of high precision plasma for metal cutting systems. We use Viton o-rings in all our torch designs. Yes, Viton does exist and yes, there is a big difference between Buna and Viton. So, for those that don't know what plasma is.......plasma is the 4th state of matter. This is the next state after gas. To get to this state you superheat the gas which makes it ionized and capable of carrying electrical current. An electrical arc that we create, much like lightning, follows the ionized gas to complete a circuit where the conductive metal in it's path is cut like a hot knife through butter. One of the gasses we use to convert to plasma is 99.999% pure oxygen. Now, what separates the arc chamber from the other parts of the torch and the outside world? Yes, o-rings. Have you ever seen an O2 fire? I have, Buna induced, silicone lube induced and other material induced also. Well of course at temps ranging around 5000 degrees outside the torch and up to 40,000 degrees in the arc chamber. But I have only seen one Viton fire and it was related to our purchasing people sourcing Chinese made o-rings. If Viton can stand up to this application it's worth the cost. Is it overkill for recreational scuba? Most likely. Would I use anything less than Viton? Not likely.