Exploding scuba tank kills one - Florida

[openmindOW]

The burst disc issue has been raised on this thread, but I want to follow-up.

Can anyone explain why the burst disc did not prevent rupture of the tank wall?

 

[Micamber]

My condolences to all of the family and friends. This is so strange. So sad.

The earlier mention of Mr. Vanhorn's cave training got me thinking…

Do I remember correctly that some divers in the cave diving community defeat the burst disk system by "doubling up" the disks?

I seem to recall that the burst disk was seen as a failure point, in that it might rupture even when there was no over-pressure situation. This would be a very bad thing in a cave situation so I can follow the logic, even though I would never follow the practice for the kind of diving that I do.

You would have to be *so* much more careful with your maintenance and filling protocols to offset the risk added by defeating this safety system.

Can anyone confirm that I'm not imagining that this practice exists? If it does exist, is it common in the Fla. area?

 

[ktomlinson]

My condolences to all of the family and friends. This is so strange. So sad.

The earlier mention of Mr. Vanhorn's cave training got me thinking…

Do I remember correctly that some divers in the cave diving community defeat the burst disk system by "doubling up" the disks?

I seem to recall that the burst disk was seen as a failure point, in that it might rupture even when there was no over-pressure situation. This would be a very bad thing in a cave situation so I can follow the logic, even though I would never follow the practice for the kind of diving that I do.

You would have to be *so* much more careful with your maintenance and filling protocols to offset the risk added by defeating this safety system.

Can anyone confirm that I'm not imagining that this practice exists? If it does exist, is it common in the Fla. area?

It exists. Some double up, some use a bolt. Like you, it's not something that I do (I'm not a cave diver). I wonder when the practice started...has anyone ever heard of a burst disc blowing during a dive?

 

[cool_hardware52]

The burst disc issue has been raised on this thread, but I want to follow-up.

Can anyone explain why the burst disc did not prevent rupture of the tank wall?

1) Wrong disk installed. There are various disks available depending on the type of cylinder it is intended to be used with. This often occurs when tank valves are swapped between cylinders of different WP. For example a valve from a 3442 psi tank screws right into a 2250 psi LP tank.

2) Doubled disk ed or "blanked" , effectively no over pressure relief.

3) Damaged or defective tank wall that failed at a pressure below the burst pressure of the disk installed.

No way of knowing based on the currently available information.

If I had to speculate, I'd put my money on either a 6351 alloy al 80, or on a damaged steel tank. Both could be wrong.

Tobin

 

[JahJahwarrior]

Double disks are only kosher on steel tanks. Typically shops will refuse to fill an aluminum tank without the proper burst disk.

I guess then it also becomes important to know if it was a side mount diver.

Tobin brings up a good point. Are burst disks of various burst pressures made with identical threads for other gas uses such as industrial tanks? We use a different valve thread count for high pressure tanks, but the same threading and count for all burst disks...

 

[Some X Dry]

My condolences to all of the family and friends. This is so strange. So sad.

The earlier mention of Mr. Vanhorn's cave training got me thinking…

Do I remember correctly that some divers in the cave diving community defeat the burst disk system by "doubling up" the disks?

I seem to recall that the burst disk was seen as a failure point, in that it might rupture even when there was no over-pressure situation. This would be a very bad thing in a cave situation so I can follow the logic, even though I would never follow the practice for the kind of diving that I do.

You would have to be *so* much more careful with your maintenance and filling protocols to offset the risk added by defeating this safety system.

Can anyone confirm that I'm not imagining that this practice exists? If it does exist, is it common in the Fla. area?

I can only confirm that there are mavericks in any discipline. So far the experience I have had with both Tech and Cave divers is there are some who do and some who don't practice mods to allow overpressure on tanks. Whether overfilling/ mods were the cause of his death or not. I'm sure with Russ's tragic death there will be some who will change their ways. I Hope so... At the very least bring tank safety to everyone's mind from here on out. You can bet I will be extra careful with mine.

 

[jdcpa]

Just looking at the pictures on the local news, this was an explosion, not a shrapnel issue.

The explosion blew out windows and a door, and damaged cars in the parking lot. Blew out all or most all of the glass in the windows.

It indicates to me the explosion occurred inside the condo.

I don't know anything about tanks bursting, but this was an explosion based upon the pictures.

Nothing like the discussion of a tank bursting or the pictures shown here.

My gut tells me something else occurred with it or the tank held somethign else.

Or it could be I know nothing about this and I am completely wrong.

Too weird.

 

[Splitlip]

Could you tell if it was aluminum or steel?

 

[Jax]

The article says "he just came back from Iraq".

Question:

If the tank in question was steel, and somehow had salt water in it, and it had been filled and was sitting there for the year he was gone, would the salt water damage be sufficient to really weaken a tank such that an accidental drop would cause an explosion?


EDIT: BTW, in defense of the dive shop owner -- he may have given a completely accurate discussion on the alloy and the pressures . . . but the reporter would "edit" for brevity and clarity, and make it wrong.

 

[Jax]

Violent scuba tank blast kills Iraqi war veteran at St. Petersburg condo - St. Petersburg Times

Russell Vanhorn II, 23, an Iraq War veteran, was the victim of the peculiar fatal explosion, according to police and his father, Russell Sr., who has his own questions.

"Something ain't right because some of those tanks he had were pretty new," said Vanhorn Sr., 55, of Hills, Iowa.

Operative word: Some.