Nitrox regulators?

[Genesis]

There are more than a few confirmed cases of a flash burn on a standard, not cleaned regulator by each of the manufacturers. Enough that it's just plain not worth the chance of destroying your gear if not something far worse.

Your argument is noted for FO2s over 40%. But we weren't talking about that, were we?

As I noted, the issue with cleaning (or not) on high FO2 mixes does not prevent combustion, since there ARE combustible parts in ALL regulators. What it does for you is attempt to keep a potential flash-fire from propagating out of the immediate area where it happens, which could be catastrophic.

If you claim there are "more than a few" documented cases of flash-fires on RECREATIONAL mixes (not in the tank, in the REGULATOR), I'd love to see your documentation on this.

I've looked for it and have been unable to find it. Further, NASA has made quite a study of this matter, and they've had quite some trouble getting FO2s up to 40% to ignite, even using extraordinary tests (solenoid impuse valves @ 3000 psi!)

Over 50% all bets are off; for all intents and purposes FO2s over 50% should be treated as 100% O2.

BTW, the specific issue is one of the use of silicone .vs. Christolube or Krytox as lubricant.

Any manufacturer still using Silicone lube, and any SHOP still using it for general purpose regulator lubricant is one you should not purchase equipment or service from. Silicone is vastly inferior in terms of lubrication properties to Christolube. Given the miniscule amounts of lube required during assembly, it is pure idiocy to use silicone in regulators these days for such jobs.

 

[HammerNoMore]

shrwdtech once bubbled...
There are more than a few confirmed cases of a flash burn on a standard, not cleaned regulator by each of the manufacturers. Enough that it's just plain not worth the chance of destroying your gear if not something far worse.

You've said this before, and when I asked for examples you clammed up like a Clinton grand jury witness. Being a self proclaimed expert doesn't mean anything if you are not willing to offer support to your arguments.

 

[Padipro]

Guys, you know it as well as I do that all the talk of doom and gloom from the manufactures is just their way of covering their asses, (CYA). Of course they're going to recommend that their equipment be cleaned by an autheroized (incert the manufacture here) service center because in this law suit crazed country we live in they don't want to be liable if anything happens. We've all seen it before, a woman spills hot coffee in her lap while she's driving and sues Mickey D's because "They didn't tell me it was hot". If some bozo, that doesn't know what he's doing, decides he wants to mix up some home brew, things go wrong and he burns the house down all he has to say is "They didn't tell me I had to have it cleaned" and the manufacture is going to pay throught the nose. So to cover their ass thay say every piece of equipment requires cleaning prior to use with Nitrox regaurdless of the percentage used. It also generates more income for their certified repair technicians because you're paying double the cost of normal servicing to have it "O2" cleaned.

If there was such a high risk of flash burn with non O2 cleaned equipment being used with percentages of O2 less then 40% you'd be seeing things burn up on dive boats all the time. I've been diving Nitrox sinse the mid 90's on boats where every diver was breathing it and I've never had or seen a single incident.

shrwdtech, as the others have said if it's so dangerous and "I'm going to get someboby hurt" then where's the proof? Show us the statistics. I've done the research as well and everything I've ever found on the subject has come to the same conclusion that Genesis quoted.

I'll be waiting for the proof.

Scott

 

[shrwdtech]

Everybody... especially Padipro, sorry I sounded grouchy yesterday. Must have been the Monday thing. No ill was intended.

As far as clamming up. I am telling you and admitting to more than any other manufacturer's representitive is here. I'm sorry if I cannot or am not allowed to state circumstances. If you are able to, join me at DEMA at any one of the 6 seminars I'll be teaching, and I'll be happy to go over it all with you in great detail. Contact your local dealer if you are not with one already and see if he'll let you have one of his spots. I'd say stop by the booth, but I'll not be in it.

Your thoughts and approach to this is too similar to so many things that turn up bad in our lives. Using an admittadly much more drastic example to make a point here, but, the O-ring Seal on the Challenger wasn't supposed to fail. Should have been 100% safe according to the Engineers. The insulation foam on the Columbia shouldn't have been heavy or hard enough to damage the wing. It had happened on take off many many times before without harm.

And even though these disasters probably would never happen again, and should not have occured, major changes were made in design, as well as the way things were done at NASA.

This past winter our one of our local Reps witnessed 2 flashes on regs that were not cleaned on the same boat in. Should it have happened? No. Even I agree to that. Did they do anything wrong? No. Regs were close to new had not had a first annual service yet, and were in good condition. But it still happened. And it does happen.

I don't make a dime off of you getting your regs serviced. And as for it being an income source that generates so much cash, please let me know what shop that might be at. I could use the extra cash. Every dive shop I've worked for, managed and owned couldn't buy lunch on the amount of profit we'd make off of O2 cleaning your gear.

I really don't care one way or the other what you do. People come here and ask questions, and get ideas, opinions and thoughts, both good and bad from people. When you get a REAL opinion based on the facts that the Manufacturers have collected and offer you want to argue and accuse us of either not knowing what we are talking about or gouging you. Great! Argue away and do what you want.

But, the official stance is gleaned from being an Instructor, Course Director, and one of the heads of Technical Support here. Not to mention handling both liquid and gaseous oxygen as an aircraft mechanic. The stuff CAN be safe. It CAN be quite stable and easy to use, and it IS dangerous when you think you have it covered and think you know it all. It has nothing to do with covering anybody's ass. Mine is covered. If you want to play russian roulette with your dive gear, knock yourself out.

I personally do NOT use any regulator with enriched air that has not been serviced for use with enriched air. I teach every single one of my Nitrox and Advanced Nitrox students to do the same. Most training agencies will agree with that. The simple fact that it COULD happen is not worth the end result if it should happen.

 

[Genesis]

in a reg I can find any kind of report on turned out to be a bottle full of 80% with a non-cleaned regulator, even though the original report was that it had flashed on a "recreational" mix.

Again I challenge you (or anyone else) who claims doom and gloom to produce some documentation. Destructive events like this tend to draw investigations, especially if there is property damage or personal injury involved.

There are reports of people having valves flash on deco bottles, but those are KNOWN to be 100%. There are also plenty of people who have had trouble PP filling bottles, and especially while boosting O2.

Advanced nitrox / deco bottles (> 40%) are an entirely different matter. As I've said, >50% you may as well treat as if it was 100%, because for all intents and purposes it is.

As I've also said, you can clean all you want, but I'll bet that I can flash it anyway if I mishandle it intentionally with a high FO2 mix in there. NASA could make it happen with some regularity when they tried, and there are combustable materials in ALL regulators and valves. At a minimum the seats and O-rings will burn like hell in an oxygen atmosphere, and the overpressure that results will lead to "great balls of fire" or even explosions. This is why you use BRASS regulators, not aluminum (or titanium) ones - brass will NOT light - and keep body parts AWAY from potential component ejection paths while SLOWLY turning on valves!

Also of note is that NASA attempted to make recreational-class (under 50%) mixes flash even with GROSS contamination and had a hell of a time making it happen. Even with intentional ignition sources and fuel present - regs that on teardown later were described as "filthy." Even using solenoid valves that go from closed to wide-open in milliseconds, applying 3000 psi surges on purpose to the regulators - something you could NEVER do by hand.

Interestingly enough, the partial pressure does not appear to be the controlling factor on ignition and sustaining combustion when it comes to Oxygen - its the FO2, not the PO2 that matters.

This is why Hydrogen/Oxygen mixtures can be used at great depths - a mix of under 4% O2 will not combust with Hydrogen, irrespective of the PO2 and PH2! Of course you can't breathe it under ~100' as it is too hypoxic (16% is the "lower normal limit") to sustain normal physiological function and its a biatch to get the mix right - be off just a bit and you go BOOM! It is for those reasons that its not commonly used.

This is contrary to what is intuitive - you'd think that if the critical percentage of Oxygen is 4% for ignition of Hydrogen, then if you were at 10 atm with a FO2 of 4% you'd have a 0.40 PO2 and it would go "BOOM!" Maybe even spontaneously! Say much less putting a 4% O2 / 96% H2 mix in a cylinder and cranking it up to 3000 psi.

But you'd be wrong; it won't ignite, no matter how hard you try.

 

[mars2u]

shrwdtech once bubbled...


This past winter our one of our local Reps witnessed 2 flashes on regs that were not cleaned on the same boat in. Should it have happened? No. Even I agree to that. Did they do anything wrong? No. Regs were close to new had not had a first annual service yet, and were in good condition. But it still happened. And it does happen.

What was the O2% in the tanks?

Were the tanks O2% verified before filling (I hope) and after the incident with MORE THAN ONE O2 analyzer? (could have been a faulty analyzer or filler if it was supposed to be less than 40%.)

Which regs were they?

O2 at 21% is flammable also. Would your opinion be that the reg could have flashed using regular air?

Just curious about the details of this. Has anyone documented this to the manufacturer? I would be surprised if there wasn't a recall or at least an investigation on their part if it happened twice to one shop.

Did you get a response from the manufacturer?

Just trying to get more info here since you peaked my curiosity.

Thanks in advance

 

[shrwdtech]

Mars2u...

The mix was 32%.

I am the person you'd contact at the manufacturer.

And, I'm sorry to say, I'm through with this thread. The question was asked, and I offered the manufacturers official stance. Even tried to explain it in as far as I'm allowed or capable.

I also gave the common sense one and instructional based opinions as well.

This is obviously going to be debated forever, and the people are going to have their opinion no matter what you try to tell them. Since everybody is obviously an expert on the subject, I'll leave you to their opinions.

Should you have any questions regarding Sherwood or Genesis Scuba equipment, feel free to send me a line or two at technicalsupport@cramerdecker.com

Good Luck!

 

[HammerNoMore]

shrwdtech once bubbled...
And, I'm sorry to say, I'm through with this thread. The question was asked, and I offered the manufacturers official stance. Even tried to explain it in as far as I'm allowed or capable.

I also gave the common sense one and instructional based opinions as well.

This is obviously going to be debated forever, and the people are going to have their opinion no matter what you try to tell them. Since everybody is obviously an expert on the subject, I'll leave you to their opinions.

You know. I have got to say that I find that Sherwood/Genesis is being grossly negligent in this matter. As I see it:

1) The majority of divers believe that any reg in annual service is perfectly safe with EAN mixtures up to 40%.

2) An Sherwood/Genesis representitative claims that the company has documented evidence of many flash occurances with EAN < 40% and non "O2 clean" regulators. Same representative also claims the company will not allow him to make such evidence public.

3) Therefore the company has evidence that the diving community at large is in vast danger and is hiding this information.

James

 

[DMTJLA]

I find all of you guys amazing. I have to agree w/ Sherwood . I work in Hyberbarics for 3 yrs and 2 yrs offshore . In no way would we run anything over 22% with out it being O2 cleaned. The training agenies leave the responablity to follow the SCUBA companies. When they make a reg that is nitrox ready to 40% is it made to be dedicated to nitrox it is not made to be switched around from air to nitrox and back. I dive and teach nitrox , I will not let my students use a reg that is not nitrox ready. It is a CYA thing. All it takes is one time. As for James, wake up . I know for a fact that all the major SCUBA companies know of what could happen and they are playing the numbers, chances are slim but a flash under 40 % can and has happen. Navy nitrox diving volume 2 page 10-7 . Once a regulator has been made a nitrox reg it can only be use w/ nitrox. Wonder why?

 

[MechDiver]

shrwdtech once bubbled...

As far as clamming up. I am telling you and admitting to more than any other manufacturer's representitive is here. I'm sorry if I cannot or am not allowed to state circumstances. If you are able to, join me at DEMA at any one of the 6 seminars I'll be teaching, and I'll be happy to go over it all with you in great detail. Contact your local dealer if you are not with one already and see if he'll let you have one of his spots. I'd say stop by the booth, but I'll not be in it.

I personally do NOT use any regulator with enriched air that has not been serviced for use with enriched air. I teach every single one of my Nitrox and Advanced Nitrox students to do the same. Most training agencies will agree with that. The simple fact that it COULD happen is not worth the end result if it should happen.

I've read some worthless tripe on boards before, but this nonsense is probably close to the top award for stupidity. And I don't care if you're a course director for 10 agencies, you're still putting out garbage.
Gawd, I just can't get over stupidity like this from someone who professes to be a dive professional. And brags about it no less.

I gotta leave now before I get really annoyed