Scuba tank explosion - man loses hand

[MauiScubaSteve]

As usual from that i can only infer you have no real experience diving anywher except your local area. Not everywhere in the world dives positively buoyant tanks that require more lead on the belt to sink and hold less gas at a lower pressure and weigh more than steel equivalents

As usual you seem to think that other people who do not live just as you do are not in their right mind. When in Rome what do you do? So I live in a place where steel tanks cost over 3 times as much money than aluminum and I know plenty of people in their right mind that use aluminum. I have also done a couple hundred dives in Florida and there are more than a few people in their right mind who use aluminum there. I even did my Intro to Cave class in Florida's cave country, with a highly respected Cave instructor, using his aluminum tanks.

I do own a pair of steel tanks that I wear at work, but that fact does not cause my head to swell up so big I can't get through a doorway without a chainsaw.

This is kind of like the jacket BC thing; since way, way more dives are done worldwide in warm water rental gear (or rental tanks), which BC style (or tank material) is more common worldwide?

 

[rockjock3]

Water baths do increase heat transfer slightly and can theoretically keep the tank cooler, requiring less of an over shoot on the fill pressure to achieve the service pressure once the tank cools. But in practice it does not work that well unless the water is moving around the tank as the water next to the tank warms and essentialy insulates the tank from cooler water if there is no flow to carry the warmed water away. Also, slow fill rates are still needed to allow the heat to transfer through the metal, although aluminum is much better at transferring heat than steel.

I used moving water when i fill, but your statement about a tank that has no moving water is incorrect. As you heat any fluid there is something called convetion currents. As part of the fluid heats it will travel up (as it is lighter than the surrounding fluid). This will not insulate as you stated, but actually pull cooler water towards and up the tank. No, you will not have a visible current, but your water is not staying still. It is moving around the tanks. I can fill the same rate with my tanks out of the filling tub and they are noticibly cooler when in the water tub. I don't fill fast either.

 

[DA Aquamaster]

Well sure you get convection currents - hot water rises. With no water flow it rises right up the side of the tank, and you still end up with warmer water next to the tank separating the tank from cooler water that would have otherwise offerred a better gradient to transfer heat.

You will get some cold water feeding in from the bottom, but you end up with far less cool water flow and far less cool water in contqact with the tank than if you had some significant water flow over the surface of the tank.

 

[bowlofpetunias]

Just for those interested. Murray was given a welcome back evening on Nov 28/09. He is back to work in the dive shop missing his right hand and leg. Information released in DiveLog Feb 3010 issue 259. www.divetheblue.net

 

[ancientdiver]

my shop uses custom fitted steel pipes (mega thick) with yokes to hold a bottle in case it decided to become a suicide bomb. works great.

I have had a cyclinder fully charged after it FAILED a hydro! Went to pick it up, it wasn't filled, and no note that the bottle was kaput. The shop attendant just moaned "why didn't this get filled?" So he filled it. But it had the big R on the neck for a rejected cyclinder, which he didn't observe. I get home and look and see no new 5 year date has been stamped on neck, so I'm thinking someone didn't do their job. I called and asked why, and they couldn't explain, then I asked them"what does this R mean?" Well, you get the picture. I have learned to not assume anyone is going to be taking care of my interests. I have a ton of stories like this - resorts, boat operators, shops - folks not doing their job that cost me money or coulda got me killed. Gotta be self-reliant and expect nothing from others.

 

[oxyhacker]

Not your fault. The hydro shop doesn't have a clue what they are doing.

There is nothing in the DOT regs about marking tanks "R", no matter how big they do it. If a tank is condemned, it is supposed to have the DOT specification number and service pressure XXXXXed out, or be stamped with the word CONDEMNED written out in full so there can be no misunderstanding. Not B for Bad, or F for Failed or R for Rejected (for that matter, rejecting is not the same as condemned - a rejected tank may be rehydroed later, after the problem that led to it being rejected is remedied).

The retester is also required to notify the tank owner in writing that the tank has been condemned

I have had a cyclinder fully charged after it FAILED a hydro! Went to pick it up, it wasn't filled, and no note that the bottle was kaput. The shop attendant just moaned "why didn't this get filled?" So he filled it. But it had the big R on the neck for a rejected cyclinder, which he didn't observe. I get home and look and see no new 5 year date has been stamped on neck, so I'm thinking someone didn't do their job. I called and asked why, and they couldn't explain, then I asked them"what does this R mean?" Well, you get the picture. I have learned to not assume anyone is going to be taking care of my interests. I have a ton of stories like this - resorts, boat operators, shops - folks not doing their job that cost me money or coulda got me killed. Gotta be self-reliant and expect nothing from others.

 

[bowlofpetunias]

Well the tank in this particular incident was in test, had not failed test. It was one of the shop's rental Aluminium tanks. A number of the scuba shops have replaced a pile of old tanks because of this.

 

[sydney-diver]

Well the tank in this particular incident was in test, had not failed test. It was one of the shop's rental Aluminium tanks. A number of the scuba shops have replaced a pile of old tanks because of this.

Yes my LDS has retired a number of older alloys, as far as I understand no LDS here will fill any 6351 alloy tank and most seem to be playing it safe and are refusing to fill pre-1990's alloys 6351 or not (some will if you can prove they're not 6351 from what I understand).

 

[bowlofpetunias]

Sad incident indeed and nice to hear he is back to work! I guess the up side if there is one is that many older tanks have been taken out of use!

 

[Paladin]

A lot of those old 6351 tanks seem to be popping up on ebay to be sold to unsuspecting buyers.