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I have searched for more information on this article but found nothing, have you seen anything new? I will be most interested to see what the cause of this accident was. I can’t agree enough that annual inspections, at a minimum, are necessary, non exposure to extreme temperatures or pressures as well as current hydro’s! Some of the other things that people forget about is ensuring that the cylinders aren’t stripped and repainted unless proper procedures are followed! Always have cylinders filled at a certified/approved air fill station following proper procedures.
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Hi Greg,
Everything you said about scuba cylinders is true. I think investigator’s are also looking into the possibility that the cylinder may have had pure O2 in it.
Barry
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has there been any update to this story? do they know yet what happened or still just speculating?
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johng - 9/28/2011 3:49 PM
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From KBDiverServices: Tanks don’t just explode for no reason. In fact, tanks should never explode if the burst disc is in place and functioning. Certainly heating and overfilling can cause a danger, but if the burst disc is in place, then it should rupture before the tank does. Most tanks that do rupture - do so during filling and occur when filling station attendants fail to fill at a proper rate and overfill the tanks. Tank explosions while being carried are very rare indeed. They happen most often during filling, followed closely by being stored in hot environments such as cars in direct sunlight and garages without environmental controls. Make sure burst discs are checked when visual inspections are done. Most dive shops fail to remove and inspect burst discs. I’ve actually seen some bone head divers remove burst discs and replace with burst discs rated for higher pressure tanks. This is a big no no. They do this so they can overfill the tanks without the burst disc blowing... beware when buying used tanks with used valves. Always ensure the burst disc is the proper one for the tank.
What about SLC or pure O2 in a cylinder?
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From KBDiverServices:
There were a series of AL tanks produced by a couple of manufacturers prior to 1989 that have proven more likely to explode than others due to the material they were made with. These AL tanks are the only tanks that require the Visual Plus test. Many shops will not fill them at all - even if they pass the visual plus test.
As far as o2 being the cause, o2 in the cylinder would expand in volume the same as air and cause a burst disc to rupture before the tank would explode. Certainly o2 is a more volatile gas when it comes to producing flame. It is why tanks and valves must be o2 cleaned before filling with 100% o2 and/or before partial pressure nitrox fills - which require 100% o2 be put into the cylinder before air.
Again, a tank being filled with 100% o2 is more likely to ignite, start a fire and potentially explode during filling - especially if the valve and/or tank have contaminants in them or in new tanks where the smallest sliver of steel remains lodged in the valve or interior of the tank.
It is no more likely in my opinion that a tank being carried - filled with o2 - simply exploded than a tank with air - unless that tank was overpressurized, left in sunlight or heat all day and the burst disc was changed out. The same scenario in which I could see a tank filled with air exploding. In both cases, it would be a much more likely an event if the AL tank was produced prior to 1989.
Thanks for the information! The problem with this accident is we really don’t know!
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MDW - 1/04/2012 7:32 PM
Interesting conspiracy theories. Problem is none of these "causes was mentioned in the article. There is no mention of overfilling, O2, Aluminum, heat, or impact. For all we know this was a recently hydroed and "VISed" steel tank, partially filled (to below rated pressure) with an inert gas (like helium or argon), stored in the apartment and gently handled. OK, that would be a little far fetched, but just as unlikely is that it was an aluminum tank of questionable alloy overfilled with 100% Oxygen, stored in a hot location and thrown around.
The article says "cause unknown" To me, that means "cause unknown"
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Not really conspiracy theories just a lot of variables that should be mentioned when it comes to cylinder explosions. It’s truly hard to say why that cylinder failed and killed the owner. Maybe in a year or two when the cylinder is fully analyzed we’ll have some answers.
All scuba cylinders should be treated with a lot of respect and go through regular intervals of inspection.
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During my recent VIP class at DEMA they discussed this case. The diver had filled the tank with a nitrox mix, the tank had the burst valve removed and replaced with a plug and the neck at the valve appeared to be on fire at the time of the explosion. This would have denoted the use of a petroleum product of some time not suited for nitrox and the fill with a nitrox mix under high pressure caused the neck to leak fire and explosion followed. That is what I understood the offical report to have said according to the guys teaching hte class.
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