Tank Explosion

Hi all...

There was a tank explosion at a scuba/cave diving center down in central
Florida yesterday.

One employee was killed and three divers injured.

Seems the employee dropped an O2 tank, tank valve hit the ground, loud hiss for
a moment, then the tank ruptured/exploded.

Now, in the past I can recall several instances of tanks blowing up due to
being defective/mistreated (and I think even maybe being overfilled). And I
seem to recall that some of the explosions were due to cracks that formed in
the threaded neck then at some point they very rapidly enlarged causing the
tank to rupture, as opposed to a weak tank wall or defective material in
general.

However, I dont recall any instances of an impact on a valve itself stressing
the neck enough to cause it to crack with inevitable following rupture. Does
anyone else here recall such a failure mode/incident ?

But I do seem to recall an instance or 2 of valves getting knocked off and
tanks turning into ballistic projectiles....

Given this incident, if you havent been careful in handling your tanks in the
past, you might want to reconsider.....

And I know that if I ever put a serious "wack" on a tank valve, even if it
doesnt rupture right then, it certainly could have started a crack and the tank
and the valve are heading for the dumpster pronto....

take care

Blll

"BllFs6" <bllfs6@aol.com> wrote in message
news:20040729080822.24921.00000431@mb-m20.aol.com...
> Hi all...
>
> There was a tank explosion at a scuba/cave diving center down in central
> Florida yesterday.
>
> One employee was killed and three divers injured.
>
> Seems the employee dropped an O2 tank, tank valve hit the ground, loud
hiss for
> a moment, then the tank ruptured/exploded.
>
> Now, in the past I can recall several instances of tanks blowing up due to
> being defective/mistreated (and I think even maybe being overfilled). And
I
> seem to recall that some of the explosions were due to cracks that formed
in
> the threaded neck then at some point they very rapidly enlarged causing
the
> tank to rupture, as opposed to a weak tank wall or defective material in
> general.
>
> However, I dont recall any instances of an impact on a valve itself
stressing
> the neck enough to cause it to crack with inevitable following rupture.
Does
> anyone else here recall such a failure mode/incident ?
>
> But I do seem to recall an instance or 2 of valves getting knocked off and
> tanks turning into ballistic projectiles....
>
> Given this incident, if you havent been careful in handling your tanks in
the
> past, you might want to reconsider.....
>
> And I know that if I ever put a serious "wack" on a tank valve, even if it
> doesnt rupture right then, it certainly could have started a crack and the
tank
> and the valve are heading for the dumpster pronto....
>
> take care
>
> Blll

If you are right about it being a tank of Oxygen, you should rethink the
applicability to scuba and compressed air. An explosive event with O2 may
just be hissing or gushing gas with air.

In article <20040729080822.24921.00000431@mb-m20.aol.com>,
bllfs6@aol.com (BllFs6) writes:
...
>Seems the employee dropped an O2 tank, tank valve hit the ground, loud hiss for
>a moment, then the tank ruptured/exploded.
...
>However, I dont recall any instances of an impact on a valve itself stressing
>the neck enough to cause it to crack with inevitable following rupture. ...

Not to you have evidence of such an instance here.
My assumption is that the damaged valve leaked -- not the tank.

Thus this explosion was most likely NOT due to tank failure,
but to the leaking O2. Many common things become flamable/explsoive
in the presence of high concentrations of O2.

--
Charlie Hammond -- Hewlett-Packard Company -- Ft Lauderdale FL USA
(hammond@not@peek.ssr.hp.com -- remove "@not" when replying)
All opinions expressed are my own and not necessarily my employer's.

>Thus this explosion was most likely NOT due to tank failure,
>but to the leaking O2. Many common things become flamable/explsoive
>in the presence of high concentrations of O2.

From what Ive heard, it doesnt sound like the fact there was O2 (vs any other
gas) in the tank had anything directly to do with it....

When I said tank explosion I really meant rupture.....but rupture just doesnt
seem to convey what happens when something at a few thousand psi ruptures..

So, explosion = dramatic rupture, not fast chemical reaction....

Now, maybe the O2 used the tank started some kind of corrosion crack that made
it more vunerable.....and if thats the case it makes you wonder even if it
hadnt been dropped, would it have eventually given way give XXX more fills over
YYY more years?

Now, if you have crack with gas rushing out....its physics 101 that OVERALL the
gas cools down.....but does all that gas moving supersonic through the crack
heat up areas/edges of the crack...and if you get some nearly microscopic area
hot enough with high pressure oxygen speeding by I can see the oxygen burning
the aluminum/steel and a runaway reaction helping the crack propagate
rapidly...

take care

Blll

Probably an Aluminium cylinder, as Aluminium alloy has a far lower tolerance
to deforming than steel (assuming that both cylinders are in good condition.

I do know of one occurrence of a steel twin-set that fell off the back of a
pick-up truck and bounced down the motorway at about 70mph. Apart from the
manifold being severely deformed, there was no loss of gas pressure!


"BllFs6" <bllfs6@aol.com> wrote in message
news:20040729080822.24921.00000431@mb-m20.aol.com...
> Hi all...
>
> There was a tank explosion at a scuba/cave diving center down in central
> Florida yesterday.
>
> One employee was killed and three divers injured.
>
> Seems the employee dropped an O2 tank, tank valve hit the ground, loud
hiss for
> a moment, then the tank ruptured/exploded.
>
> Now, in the past I can recall several instances of tanks blowing up due to
> being defective/mistreated (and I think even maybe being overfilled). And
I
> seem to recall that some of the explosions were due to cracks that formed
in
> the threaded neck then at some point they very rapidly enlarged causing
the
> tank to rupture, as opposed to a weak tank wall or defective material in
> general.
>
> However, I dont recall any instances of an impact on a valve itself
stressing
> the neck enough to cause it to crack with inevitable following rupture.
Does
> anyone else here recall such a failure mode/incident ?
>
> But I do seem to recall an instance or 2 of valves getting knocked off and
> tanks turning into ballistic projectiles....
>
> Given this incident, if you havent been careful in handling your tanks in
the
> past, you might want to reconsider.....
>
> And I know that if I ever put a serious "wack" on a tank valve, even if it
> doesnt rupture right then, it certainly could have started a crack and the
tank
> and the valve are heading for the dumpster pronto....
>
> take care
>
> Blll

BllFs6 wrote:
>
> Seems the employee dropped an O2 tank, tank valve hit the ground, loud hiss for
> a moment, then the tank ruptured/exploded.

That was the initial report. Since then others close to the incident say
that the tank in question was not dropped and was hooked up to a fill
station.

Brian
Edmonton, Alberta

BllFs6 wrote:
> Hi all...
>
> There was a tank explosion at a scuba/cave diving center down in central
> Florida yesterday.
>
> One employee was killed and three divers injured.
>
> Seems the employee dropped an O2 tank, tank valve hit the ground, loud hiss for
> a moment, then the tank ruptured/exploded.
>
> Now, in the past I can recall several instances of tanks blowing up due to
> being defective/mistreated (and I think even maybe being overfilled). And I
> seem to recall that some of the explosions were due to cracks that formed in
> the threaded neck then at some point they very rapidly enlarged causing the
> tank to rupture, as opposed to a weak tank wall or defective material in
> general.
>
> However, I dont recall any instances of an impact on a valve itself stressing
> the neck enough to cause it to crack with inevitable following rupture. Does
> anyone else here recall such a failure mode/incident ?
>
> But I do seem to recall an instance or 2 of valves getting knocked off and
> tanks turning into ballistic projectiles....
>
> Given this incident, if you havent been careful in handling your tanks in the
> past, you might want to reconsider.....
>
> And I know that if I ever put a serious "wack" on a tank valve, even if it
> doesnt rupture right then, it certainly could have started a crack and the tank
> and the valve are heading for the dumpster pronto....
>
> take care
>
> Blll

http://gainesvillesun.com/apps/pbcs....OCAL/207290346

http://tinyurl.com/64o95

The tank was being filled when it exploded, killing a woman.

>http://gainesvillesun.com/apps/pbcs....OCAL/207290346
>
>http://tinyurl.com/64o95
>
>The tank was being filled when it exploded, killing a woman.
>
>

Well...that certainly makes it a more "normal" type of tank failure.....

But now I am still wondering if a good whack on a valve would be enough to
start a neck crack that leads to a fast rupture?

Anyone know of any instances of that?

take care

Blll

"BllFs6" <bllfs6@aol.com> wrote in message
news:20040729124245.16931.00001838@mb-m20.aol.com...
>
>http://gainesvillesun.com/apps/pbcs..../LOCAL/2072903
46
> >
> >http://tinyurl.com/64o95
> >
> >The tank was being filled when it exploded, killing a woman.
> >
> >
>
> Well...that certainly makes it a more "normal" type of tank failure.....
>
> But now I am still wondering if a good whack on a valve would be enough to
> start a neck crack that leads to a fast rupture?

I'd bet if you put the tank in a vice to hold it still and "whacked" the
valve (making sure to catch as much of the neck as possible) with a 25 lb
sledge on a 6' handle it'd start a neck crack that would lead to a fast
rupture... I could be wrong though.

>
> Anyone know of any instances of that?
>
> take care
>
> Blll

In article <F6aOc.332$1L5.83@newssvr24.news.prodigy.com>,
"Chris Guynn" <chris.guynn@sbcglobal.N.O.S.P.A.M.net> writes:

>I'd bet if you put the tank in a vice to hold it still and "whacked" the
>valve (making sure to catch as much of the neck as possible) with a 25 lb
>sledge on a 6' handle it'd start a neck crack that would lead to a fast
>rupture... I could be wrong though.

Sufficient physical abuse will break anything.

--
Charlie Hammond -- Hewlett-Packard Company -- Ft Lauderdale FL USA
(hammond@not@peek.ssr.hp.com -- remove "@not" when replying)
All opinions expressed are my own and not necessarily my employer's.