(6/10/05) Newly exploded Luxfer

[Jim Baldwin]

I was at my LDS, Bayou Divers, in West Monroe, LA this morning. I had the opportunity to look at fresh pictures of a newly exploded Luxfer Aluminum 80. The incident happened this week.

The owner of the tank had brought it in for a new hydro, visual and fill. One of the shop owners did a visual and ran a current eddy test and it showed good.

They sent the tank across town to Monroe Welding and Supply for a hydro. When the technician started the hyrdo he got to 3600 psi and the tank exploded. It ruptured with such force that it actually damaged the heavy steel tank that they use for the hydro process.

A solid piece of metal containing about 1/4 of the threads and coming down the shoulder about a foot was what came off the tank.

The photos show what looks like rusty material in the shoulder area in several places. This was probably part of the alloy that broke down over the years. The tank was manufactured in 1988.

Because of the damage to the equipment that was done, Monroe Welding came out with a letter that they would no longer hydro a variety of tank models that were made prior to February 1988.

Bayou Divers is now refusing to fill any tanks made prior to February 1998 and are offering new tanks to the owners of these old tanks at cost.

Sorry but I didn't have any way to get a set of pictures.

 

[Charlie99]

Strange. I thought "hydro" was called that because it is done with nearly incompressible water, thereby limiting the energy stored in the tank and test system. Of course, it doesn't tank much stray air somewhere in the hydro system to cause problems.

Any hydro experts out there that can say whether this sort of explosive failure is normal?

 

[Otter]

Strange. I thought "hydro" was called that because it is done with nearly incompressible water, thereby limiting the energy stored in the tank and test system. Of course, it doesn't tank much stray air somewhere in the hydro system to cause problems.

Any hydro experts out there that can say whether this sort of explosive failure is normal?

Not an expert, but the water pressure is still at 3600 PSI so when the tank goes, it seems like its going to go somewhere. Think of a crimped off garden house suddenly being opened up...there is that initial surge until the pressure equalizes. I would guess that the explosive force would be less with an uncompressible fluid vs a compressible gas as there is less volume.

 

[Charlie99]

Think of a crimped off garden house suddenly being opened up...there is that initial surge until the pressure equalizes. I would guess that the explosive force would be less with an uncompressible fluid vs a compressible gas as there is less volume.

What you are seeing with the garden hose is the extra volume/ extra energy stored in expansion of the rubber or plastic hose. You don't see that sort of surge when you open up a faucet on a solid metal pipe --- even those that have a pipe stub with air in it to reduce the water hammer effect.

 

[wedivebc]

Bayou Divers is now refusing to fill any tanks made prior to February 1998 and are offering new tanks to the owners of these old tanks at cost.

.

Why 1998? No tank has been made with 6351-T6 aluminum since 1990 and to date no tank made from 6160 alloy has either exploded or shown signs of SSLC.

 

[cool_hardware52]

Why 1998? No tank has been made with 6351-T6 aluminum since 1990 and to date no tank made from 6160 alloy has either exploded or shown signs of SSLC.

My guess is a typo, really ment 1988, last year that Lux used 6351.


BTW never heard of 6160...... Anything like 6061?


Tobin

 

[stoddu]

...The photos show what looks like rusty material in the shoulder area in several places. This was probably part of the alloy that broke down over the years. The tank was manufactured in 1988...

Shouldn't the tank have failed the visual inspection due to the corrosion in the shoulder of the tank?

 

[wedivebc]

My guess is a typo, really ment 1988, last year that Lux used 6351.


BTW never heard of 6160...... Anything like 6061?


Tobin

OK my typo

 

[Jim Baldwin]

Shouldn't the tank have failed the visual inspection due to the corrosion in the shoulder of the tank?

I had a good look at the pictures and the tank looked fine on the inside and outside. The detoration was sandwiched between the interior and exterior. It looked like a streak of rust between two bright pieces of metal.

I also had a talk with the owner of the shop who inspected and ran the test. I know him well and I trust him. He has been an instructor for many, many years and has done hunderds of inspections. He knew the problems with these older tanks and would certainly have failed it if he had even suspected a problem.

The tank failed at 3600 psi not at the top end of its 5/3's pressure. The shop fills all their tanks to 3200 psi. This was not a lot of cushion.

And yes it was typo in the last paragrah of my first post. It is suppose to be 1988 not 1998.

 

[roakey]

They sent the tank across town to Monroe Welding and Supply for a hydro. When the technician started the hyrdo he got to 3600 psi and the tank exploded. It ruptured with such force that it actually damaged the heavy steel tank that they use for the hydro process.

Someone's not doing a hydro correctly. The volume of water that brings a cylinder up to TP is miniscule. As soon as a crack forms, the pressure drops to zero. From outside the surrounding water jacket you wouldn't even know it failed except all the test equipment's pressure suddenly drops to zero.

Roak