Lost another tank :(

[Arkman]

Last summer I discovered that my dads two tanks that I inherited were made out the dreaded 6351 alloy. At the time I didn't know anything about this problem but I quickly learned.

Last fall I bought some dive stuff from a guy on CL and when he delivered it he came with an extra tank and said he found it in his stuff and I could have it. I looked at the hydro and it was stamped 99 but I never thought to look at the manufacture date.

Today I brought it in for a fill and the shop looked and BAM! 1987. My shop has a new policy that they wont fill any al before 1990, which in this case I fully understand. They have had a first hand experience of a tank failure and decided to play it extra safe. He said he wouldn't fill it. :depressed:

Oh well, it passed the VE test last fall and as far as I know its still good to be filled. Off to CL with it I guess. I will, however, disclose to the potential buyers the tanks history

 

[letterboy]

I have a pre-90 AL tank. I can't find anyone down here in SFL to fill it. It does make a great door stop though.

 

[Arkman]

I have a pre-90 AL tank. I can't find anyone down here in SFL to fill it. It does make a great door stop though.

That would hold open one heavy door.

I feel dumb. I totally thought the two were the same age but I was looking at the first hydro date...not the manufacture date. The one is a 99 the other is 87.

 

[letterboy]

ohh-well, no loss for your pocketbook though right?

I also hear they can be cut in half and make nice dinner bells.

 

[letterboy]

ohhh - I bet they would make a nice clearing barrel if you have a concealed carry weapon you want to clear before going into your house . . .

 

[Rick Christ]

I have a pre-90 AL tank. I can't find anyone down here in SFL to fill it. It does make a great door stop though.

If you are in the keys, I have shops that will fill 6351T6

I will try to educate the diving industry one more time, but I don’t have much faith it will work/help

Per PSI data:
They know of 23, 6351T6 tanks that have turned into a hand grenade
Two have happen after the VE
In the same time period of these 23 ruptures, 57 steels have ruptured, but you all think that your steels are safe. I don’t get you guys,
This bad 6351T6 thing all started withHM220D, the dive community read part of that notice and came to the finding that because DOT outlawed poison gas in 6351T6, that this meant that compressed air was also included, it is not. Read 49CFR 180.209m

#1 All Tanks fail, The question is when will it fail. That is why we are working so hard to get all tanks tested, that is why we tell you not to overfill, When you do something outside of the prescribed use of that tank. You are playing Russian roulette, you do not know if/when that tank will blow. I watch this everyday, I can see the expansion happening right before my eyes. If the tank is at yield point I can see that and almost every time, I have been able to shut down before rupture, except two times. The test equipment is made to handle a rupture. The ones I cannot see and stop are when the valve threads come out of the tank at pressure. Every time that happens it cost me $21.95 for a new burst disk in the test jacket and I put 10-20 gallons of water on the floor in 1.5 seconds.
Why do these cowboys in the dive industry think that they are smarter then the scientist, engineers and the DOT. I don’t understand.

I have a shop in Marathon that will not fill a steel tank. Do you know why? It’s real hard to argue with them when someone got blown through the wall by a steel tank rupture. But you all think your steel tank is safe but these 6351T6 are not safe, Try telling them that a steel tank is safe to fill. I've seen it, Its not pretty.

6351T6 tanks are as safe as any tanks is

 

[fire_diver]

Don't bother with the truth. A fraction of a fraction of a percent of 6351 tanks had catastrophic failures. DOT wouldnt even condem the tanks, but the shops refuse to fill them. Just like the poster said, "nothing pre 90". Pre '90 catalinas weren't 6351, but most shops wont touch them either. It's the typical knee-jerk reactionism. But in the end, it's "thier" shop and they can operate by any rules they want.

 

[flots am]

I will try to educate the diving industry one more time, but I don’t have much faith it will work/help

I can't blame them at all. The employees filling tanks aren't always rocket scientists or metallurgists, and you need to be able to give them an easy-to-implement (and understand) rule.

"We will fill no tanks manufactured before 1990" is a much safer and easier rule than anything involving knowing the manufacturer and alloy and whatever else you need to know.

flots.

 

[Arkman]

@Rick Christ-

I'm inclined to agree with you. I don't know the statistics and facts all that well but I've done a little research and like someone said, its just a fraction of a fraction of a percent or something. I've never really done the research on steel tanks but it would be interesting to see.

I'll give you a little insight to why my shop is feeling this way. Not that long ago they had a failure in their shop. Not a scuba tank but an aluminum filter bottle connected to the cascade the fill from. I don't understand the setup so I might be a little off of exactly what happen but close enough. One of the guys in the shop was standing right in front of the bottle but luckily bent over. We was injured but nothing serious, just some stitches. If he would have been standing normal that shrapnel would have been in his face. I don't want to think about what that would have been like.

The Filter bottle was aluminum and according to him it was the 6351 alloy. Now I don't know if thats true or not.

After an incident like that its hard to see the real "truth." you see everything from a different point of view. Its easy to find a lot of information about the failure of these tanks if thats what you are looking for, but you won't see, like you said, the steel tank failures. Tunnel Vision. If it were my shop, I'm sure I'd do the same thing. I respect his decision. The gentlemen that was injured is a friend of mine too.

If you can point me to the stuff about the steel tanks that would be interesting as well.

 

[Rick Christ]

I can't blame them at all. The employees filling tanks aren't always rocket scientists or metallurgists, and you need to be able to give them an easy-to-implement (and understand) rule.

"We will fill no tanks manufactured before 1990" is a much safer and easier rule than anything involving knowing the manufacturer and alloy and whatever else you need to know.

flots.

If your employees are so stupid, I don't think they should be anywhere around a fill station.
Catalina Cylinder has never made a tank out of 6351T6. All Catalina's are 6061T6

@Rick Christ-

I'm inclined to agree with you. I don't know the statistics and facts all that well but I've done a little research and like someone said, its just a fraction of a fraction of a percent or something. I've never really done the research on steel tanks but it would be interesting to see.

I'll give you a little insight to why my shop is feeling this way. Not that long ago they had a failure in their shop. Not a scuba tank but an aluminum filter bottle connected to the cascade the fill from. I don't understand the setup so I might be a little off of exactly what happen but close enough. One of the guys in the shop was standing right in front of the bottle but luckily bent over. We was injured but nothing serious, just some stitches. If he would have been standing normal that shrapnel would have been in his face. I don't want to think about what that would have been like.

The Filter bottle was aluminum and according to him it was the 6351 alloy. Now I don't know if thats true or not.

After an incident like that its hard to see the real "truth." you see everything from a different point of view. Its easy to find a lot of information about the failure of these tanks if thats what you are looking for, but you won't see, like you said, the steel tank failures. Tunnel Vision. If it were my shop, I'm sure I'd do the same thing. I respect his decision. The gentlemen that was injured is a friend of mine too.

If you can point me to the stuff about the steel tanks that would be interesting as well.

The data I gave was from PSI