Deco Cylinder Mishap

[openmindOW]

I have been criticized for being lazy because I do this... but I agree. My regs stay on my deco bottle all the time, unless it's being filled.

How long do the bottles go between use or fills?

 

[Hatul]

So what do I put over the valve for my 40% + deco bottles?

I think 40% O2 or less should be safe regardless. You can do an experiment: take a match on some metal extension like a vice grip, put on goggles, light the match and blow the gas at it. I suspect it will blow the flame out rather than making it flame up.

 

[The Chairman]

How long do the bottles go between use or fills?

A week to a month. I don't keep it pressurized though.

 

[beaverdivers]

This terrible incident is a shocking reminder that O2 use Certification is ONLY valid for one year.

In no way am I implying that the gear involved in this accident was not in O2 cert.

The message is clear, proper O2 handling is very important.

 

[Wookie]

This terrible incident is a shocking reminder that O2 use Certification is ONLY valid for one year.

In no way am I implying that the gear involved in this accident was not in O2 cert.

The message is clear, proper O2 handling is very important.

Last I checked, Advanced Nitrox certification lasted forever.

 

[ianr33]

I think he was talking about O2 cleaned tanks/regs.

In reality they are only clean until they get dirty.

 

[Wookie]

I think he was talking about O2 cleaned tanks/regs.

In reality they are only clean until they get dirty.

My bad, and apologies. I've never seen an O2 cert on a cylinder. As far as I'm concerned, the inside is clean until a contaminant is added. The valve is clean until it is exposed to the atmosphere. I happen to inspect mine with a UV light every year, of course lots of contaminants don't fluoresce, and lots of stuff that does fluoresce isn't necessarily incompatible with O2.

Personally, I think O2 safety has a lot to do with common sense.

 

[The Chairman]

Luck is no accident.

 

[suprane]

I have been following this thread and do not understand how the O2 rich air in an auto interior caused an explosion. I can see a very hot, uncontrollable fire, but what would fuel a violent explosion?

In an extremely oxygen enriched environment the ensuing fire is often so rapid, hot, and violent that it mimicks in all regards an explosion! Oxygen is an extreme accelerant! There are several videos on youtube that demonstrate this phenomenon! Simply do a search for "oxygen tank explosion".

In the hospital we try to never store oxygen (or any flammables, for that matter!) in enclosed or poorly ventilated areas. What you want to avoid is the build-up of high levels of oxygen or flammable vapors in a confined area. In the OR we have a waste gas system that actively removes the spent anesthetic gasses and oxygen to the outside of the building. And if we are doing a procedure under local anesthesia or with sedation and the patient is wearing a simple O2 mask or nasal cannula, we make every effort to ventilate the area around their face and suppress any possible ignition sources. An OR fire can be disasterous! And keep in mind nitrous oxide ("laughing gas") is just as vigorous an accelerant as oxygen!

I can easily see where an unnoticed leakage of 100% O2 in an enclosed vehicle could cause exactly what you saw with David's truck! Personally I think it is a much better idea to carry such tanks in the open bed of your truck where any leakage can simply escape into the atmosphere and not reach a "critical" concentration! And if you must carry them in the passenger compartment make sure windows are cracked and there is a constant turn-over of the air within the car. (Read that as "well ventilated"!)

 

[DTm]

Here are photos of the plastic DIN plugs and the vented XS Scuba valve:
View attachment 117227View attachment 117228

I can't think of a disadvantage to the design of the metal plugs you're using, except when pressurized there's no way to relieve the pressure from the O ring except by unscrewing under pressure which could dislodge the O ring. The plastic plug has to be designed this way because the material is not strong enough to hold back the high pressure and could blow out otherwise.

Adam

Someone correct me if I am wrong... even though these plastic DIN plugs might vent the leaking 100% O2 in the deco bottle wouldn't that create situation of putting or having hydrocarbons in a pressurized O2 rich environment just in the space between the value and plug - thus lowering the flash point of the hydrocarbon and thus creating the ignition source.

I do not know seem like from what I know putting a plastic cap on would be a worse idea than a metal one. The metal ones sound like a they are a bad idea too, at least they would wait till you wrench them off. The idea of having the reg on them seems like it might be a good idea - with the concept of just containing the O2 from a cracked (slightly opened) value, or a bad value. While we cannot plan/prevent for every miniscule event, what happens if the regulators also free flows?

I think the best idea to prevent an accident like David’s is to make sure that your O2 is stored and transported in a well-ventilated area and away from fuels. If it is in the bed of your truck great - if it is in the cab or passenger compartment crack a window. Make sure all your tanks are secured to prevent falling.

There is so much we do not know about David’s actual accident. I am not sure any of that would have prevented.

I wish David well and hope to see back out at the lake soon.