View Full Version : Aluminium Cylinder Explosions

Capt Nemo
11-06-2012, 01:05 AM
Here's a list of the cylinders made with 6351 T6 aluminium.


This alloy has a problem with sustained load cracking, and may fail explosively. Any cylinder made before 1990 is suspect, and many dive shops will not service or fill any aluminium cylinder made before then.

Here's the homepage. (some photos can be gory if you follow the links)


11-06-2012, 03:34 AM
Thanks for the heads up. Although I'm not sure how to determine the age of my tanks. I see the markings imprinted on the crown, but its unclear what they mean.

Capt Nemo
11-06-2012, 11:51 AM
Here's a pic of one of mine. I just replied to a Craigslist ad where they didn't know what to do to scrap a cylinder, so I made a pic. The original hydrotest date is when the cylinder was made. If you have a one of the bad cylinders, empty it, remove the valve, and drill a 1/2" hole through the pressure stamp. The cylinder should fetch around $30 at the scrapyard.


Capt Nemo
11-08-2012, 09:49 PM
Here's how an aluminium cylinder is made.


11-10-2012, 08:36 AM
I have seen the big cylinders that they use for welding (the green ones) an there was a place that sold them. they had one that was in peices on a wall. An the owner told me the story about it. It was not pretty. As he went an told the story the guy that was filling the tank didn't survive. When the tank blew the guy was blown to shreds like he was holding a bomb and it went off in his hands and there was peices of the guy all over the room. An the tank that he wa filling was only a quarter full. The owner also said that it matters not if you fill a scuba tank or a welding tank there is so much pressure inside the end result when a tank explodes is not a pretty site.