O2 tank explosion

[DandyDon]

Black Jack, do you know if the last hydro included a VE?

 

[UnderSeaBumbleBee]

. . . .

 

[Lobzilla]

I'll be very interested to see the results. Just a theory, but, given the facts at hand, I would look at the possibility that when the tank fell, the valve hit something and it bent, causing the high pressure O2 to leak out (probably quite fast) One of the things we teach and practice when gas blending is that its not a good idea to squeeze high pressure O2 through small spaces at high rates of speed. I would imagine that if that valve bent and allowed O2 to squeeze past the threads, it would have been fast enough to actually ignite the metal in that area, as soon as it was ignited, it would have spread inside the cylinder causing an immediate, huge increase in pressure...

So, (and it may be difficult/impossible) it will be worth looking into to see if the valve was damaged and cause the explosion, or vice versa...

Just a theory worth looking in to...

There is also the possibility that the valve rotated on impact and the friction in the threads caused ignition of metal dust and/or lubricant. There is one reported and investigated case where someone tried to tighten the valve of a filled O₂ cylinder with explosive results.

Best thing to do is if you are storing bottles that are full is to chain them. Set a designated area and put 2 eyehooks in the wall. Then get you a length of chain and a snap type ring to go on the ends. This is how we have to secure our 50lb CO2 tanks and nitrogen tanks.

OSHA requires compressed gas cylinders to be secured for a reason. Even without an explosion, a full cylinder with a broken-off valve becomes a missile that fully penetrates a cinder block wall - as shown in mythbusters.

 

[sharksdelight]

Ed,
Glad you are there and can pitch in. Both Cindy and Rick will need much assistance as the dust clears. Personally, I feel a bit helpless to do much from 3,000 miles away in San Diego but one couldn't find nicer folk than Rick and Cindy.
Steve

 

[Black Jack]

Hey Steve,

Thanks, but I'm not being much help other than helping clean up, storing some stuff, and answering lots of questions from various investigators. I hope to be of greater help as time goes by.

As for the VE, I don't have direct knowledge of whether it was done or not so I'll leave that for comment once the investigation is complete. I will say that Rick was quite anal about his dive gear.

 

[DandyDon]

As for the VE, I don't have direct knowledge of whether it was done or not so I'll leave that for comment once the investigation is complete. I will say that Rick was quite anal about his dive gear.

I certainly don't mean to be critical of the nice couple as they sound like super people. I only wish I had a lot of friends who thot so highly of me, and I certainly wish them both the best in their recovery.

This is in the A&I forum tho where we strive to learn from accidents of others, so I have to ask: If he's so careful, why was the tank standing & loose? I was taught otherwise in OW class and have always adhered to better tank safety.

thanks

 

[Black Jack]

I've not spoken to Rick since the accident so I don't have specifics on how the tank was knocked over or dropped. I expect that once he has recovered a bit more we will better understand if the tank was dropped, knocked over, or otherwise unsecured. I'd also say on a more general note that I'm a pretty carefull guy but I've made mistakes in my time as have most of the folks I know.

The A&I part of this will unfortunately not be complete for a while because the experts have to all look at what happened and render opinions. That's one of the reasons I've only posted what I know firsthand to be true and that I've been given permission to post. Believe me ALL of us around here want to figure out what happened as soon as possible. As someone who boosts and fills O2, I'm particularly interested in any possible lessons learned that will help me mitigate my risks.

Ed

 

[DandyDon]

but I've made mistakes in my time as have most of the folks I know.

Oh I understand that - me more than most. If it's a case of even the best screw up, ok - or whatever...??

 

[nadwidny]

This is in the A&I forum tho where we strive to learn from accidents of others, so I have to ask: If he's so careful, why was the tank standing & loose? I was taught otherwise in OW class and have always adhered to better tank safety.

OW students are taught to not stand their unattended tanks up because if they fall over the tank could crack the tile on the pool which means the LDS would have to pay for the repair. Plus it is supposed to get the student in the boat dive mindset where a standing, loose tank is never a good thing.

I have yet to see an LDS that stores their tanks other than standing and loose. It is a standard practice because tanks are not eggs.

 

[DandyDon]

I have yet to see an LDS that stores their tanks other than standing and loose. It is a standard practice because tanks are not eggs.

Now that you mention it, I guess so. Thanks