Tank explosion kills one - Cozumel

[Bob DBF]

In the meanwhile, search the DOT website for the failure analysis report. A 6351 alloy AL80 cylinder failed during a fill - not from crown cracking but from a manufacturing slag inclusion. The cylinder was otherwise well maintained.

**** happens.

A manufacturing slag inclusion could happen in any tank, as there is no test to screen all newly manufactured tanks, except a hydro and viz, it could be a catastrophic problem lurking in any tank you handle. Thanks for giving me one more issue to worry about.

**** always happens.



Bob
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"According to Department of Transportation records, 12 of these tanks in the United States, 17 worldwide, have exploded since 1986, almost all of them while being filled. For some proportion, consider that approximately 25.4 million tanks were made from the 6351 alloy." The latest explosion may not be reflected in the quote.

 

[CraigAClark]

Yes, except that burst disks are rated for higher pressures than the cylinder itself. It will only rupture when the pressure in the cylinder has exceeded its normal working pressure. A 3000 psi cylinder will have a burst disk rated at 3500 psi or higher, so a bad tank can explode before the burst disk ruptures.

Back in the 80's and 90's, every burst disc or burst disc plug assembly for a working pressure of 3000 psi was rated, when new, to 4800 psi. Just like cycling of a scuba jug, final separator and filter tower(s) of a filling station compressor, they weaken with each cycle.

The biggest culprit for people getting hurt or killed from tank explosion during filling, is the dive industry itself. By not requiring containment fill stations, dive operators might just as well have put a gun to their employee's head and pulled the trigger. I'm totally surprised that a company would issue insurance coverage to these operations. But then again it all boils down to $$$$ over employee safety.

 

[Basking Ridge Diver]

The biggest culprit for people getting hurt or killed from tank explosion during filling, is the dive industry itself. By not requiring containment fill stations, dive operators might just as well have put a gun to their employee's head and pulled the trigger. I'm totally surprised that a company would issue insurance coverage to these operations. But then again it all boils down to $$$$ over employee safety.

Ummmnnnnn - I don't think so. OSHA and PEOSHA (NJ based) would be all over it - I can tell you the chances of putting gun to your head and dying are much greater than a tank exploding and you being hurt or dying... That said water baths are no longer common because tanks do not explode all that often and does not guarantee your safety - you need to slowly fill the tank if you want to keep them from rupturing...
Now that said when I fill I fill slowly and I fill in a casement - because I am a cautious person with tanks under pressure.

 

[CraigAClark]

Ummmnnnnn - I don't think so. OSHA and PEOSHA (NJ based) would be all over it - I can tell you the chances of putting gun to your head and dying are much greater than a tank exploding and you being hurt or dying... That said water baths are no longer common because tanks do not explode all that often and does not guarantee your safety - you need to slowly fill the tank if you want to keep them from rupturing...
Now that said when I fill I fill slowly and I fill in a casement - because I am a cautious person with tanks under pressure.

Keep telling yourself that. The dive industry is self regulated. Don't know about your state, but it wasn't until after 2000 that Florida started requiring quarterly air test filings from each dive operation. Putting a gun to your own head and pulling the trigger is your choice, dieing because of another's lack of safety protocols isn't the same. It is negligence on their part, period. OSHA chooses to stay out of the industry, more than likely due to strong lobbying.

Slow filling will not prevent a bottle that has been grossly overfilled through out its usage or one that has cycled too many times or been repainted and oven dried from exploding while being filled. A containment fill station will not prevent an explosion either, but it will protect the operator from injury or death.

Have you ruptured a bottle in your casement to see how well it protects you? Yup, like the burst disc in your bottle valve, these stations are a one trick pony and can't be reused after an explosion. The operator walking away from an explosion is the purpose. BTW, a tank exploding in a water bath protects nothing. Putting the burst disc for an 1800 psi cylinder in the valve of a cylinder rated for 3000 psi, letting a new hire fill it and watching them react is good for some laughs and a great test for HPNS!

 

[Johnoly]

..but it wasn't until after 2000 that Florida started requiring quarterly air test filings from each dive operation.

Nope.

 

[CraigAClark]

Nope.

Really? So when in the 90's did the testing go into effect? Back it up.

 

[divenutny]

gopbroek - Thank for the update that it was a Walter Kidde tank. I have visited SCC many times over the past 10 years. I have never seen a tank that old at SCC. I wonder if the operator was doing someone a favor filling the tank, and paid the ultimate price. Thanks again

 

[robzr]

Juan leaves a wife and two children. A fund is being set up for contributions. I'll post when I have more information.

Scuba tanks at SCC are visually inspected annually and hydro-ed every five years. The hydro dates are stamped on the tanks - I've looked.

Explosion of a scuba tank is very, very rare. This was a freak accident that unfortunately took the life of a very nice young man.

Out of curiosity, how do you know this to be the case? I dove at SCC and I thought it was one of the less professional places I've dove at. I'd be amazed if their tanks were annually inspected with anything approaching the rigor that PSI/TDI would recommend.

Rob

---------- Post added November 5th, 2014 at 04:14 PM ----------

OK. It's time to call a time out. There's too much speculation, finger pointing, and rumor about what actually happened in this tragic accident.

I looked through my pictures from SCC and found one from 2007 clearly showing the hydro stamps.

That is a picture that shows a bunch of tanks, only one that I can see with a legible hydro stamp, not sure what you are calling out with this?

Rob

 

[nimoh]

So it happened once, to a cylinder that isn't made anymore and nobody who is allergic to explosions will fill?

I can live with those odds.

You actually don't know that it only happened once to a cylinder that isn't made anymore from the information given. Calling it a "very rare" occurrence is more accurate which is what Doc Harry originally said.

 

[Abdullah]

Ummmnnnnn - I don't think so. OSHA and PEOSHA (NJ based) would be all over it - I can tell you the chances of putting gun to your head and dying are much greater than a tank exploding and you being hurt or dying... That said water baths are no longer common because tanks do not explode all that often and does not guarantee your safety - you need to slowly fill the tank if you want to keep them from rupturing...
Now that said when I fill I fill slowly and I fill in a casement - because I am a cautious person with tanks under pressure.

OSHA needs a mandate (an actual law passed by congress) to create a regulation and enforce a requirement. The mandate for the recreational dive industry is nebulous at best. Where OSHA does regulate the industry is the dive staff and the dives they perform (29 CFR Subpart T). OSHA doesn't regulate scuba cylinders, they leave that up to DOT.

A fill shop in the US or its' possessions would need to comply with the general duty clause in 29 CFR 1903.1, but that typically doesn't affect an employer until after something bad has already occurred.