Posted by tleemay on October 22, 2001 at 16:14:42:
In Reply to: So the Tank Explodes - What's the Big Deal??? posted by Ken Kurtis on October 22, 2001 at 15:03:48:
"A few years ago, there was a rash of tank
explosions ("rash" being about five, all within a
relatively short period of time). The explosions
were happening mainly in Florida. The significance
is that, due to the number of caves and caverns
there, and the need for as much air as possible when exploring those, over-filling tanks is a
common and somewhat-accepted procedure in Florida. (Whether it's individuals or stores doing it is a moot point)."
Ken, I do not believe your facts are straight on
this one.
The 'rash' of exploding tanks was proven to have
been due to Sustained Load Cracking, or SLC,
of the 6351-T6 aluminum alloy manufactured
cylinders. The bulk of these tanks were, and
continue to be, used in daily tank rental fleet
in Florida, as well as many other locations
around the world. They just get inspected more
often using the now PST perscribed Vis+ method.
A quick call to one very prominent shop in the
High Springs area of cave country confirmed that
they had not had a tank explode in their area
for more than a decade.
A professional acquaintence of mine if Florida was
a victim to the inferior material used in the
exploding tank manufacturing. For more info
on Chris' experience, go here;
http://www.evcom.net/~n4mwd/chris.htm
"So why are divers willing to (literally) risk life and limb by over-filling the tank."
As someone who has worked on dive boats in my
spare time since 1995, I have seen and heard
all the reasons in the world why the crew SHOULD
over fill tanks for charters, including two of my
favorites;
"But I labled my tank to 3000 PSI - I want a
3000+ fill" over a LP 95.
"My buddy is not in as good of shape as I am and
he uses more air" during bug season over the
complaining diver using a LP 104 while his buddy was using a steel 72 - rented.
Why put the entire group of divers and crew (
remember, it's their safety too) at risk just because you need 14.2857% in your HP tank. A better, healthier solution is to lower your SAC.
For those of you who have never seen the effect
caused by an exploded tank, click on the 'Details and Photographs' link, Honestly, the pictures do
not do the effect justice. One diver in the
San Joaquin Valley had a steel 72 tank explode on
him a few years ago. I was one of the first to
witness first hand the damage of pieces of steel
shreading the bumber off of his Volkgwagon Jetta
and embedding yet other pieces into his garage
drywall so deep that they protruded into the lower
kitchen cabinents and dented his wife's
cookware... 60' feet away.