Is my cylinder made from the "bad" alloy aka AL6351?

[guruboy]

Do the Luxfer cutoff dates above indicate the LAST month of 6351 production or the FIRST month of 6061?

This page from Luxfer says those are the TRANSITION dates. I'm interpreting that as the FIRST month of 6061 but I may be wrong.
Dates when Luxfer changed its aluminum alloy from 6351 to 6061

 

[Sawdust82]

So if the first hydro date on a cylinder is 1990 or later, youre good to go? Im looking at some used gear and have been wondering about the old alloy and how to avoid those tanks...

 

[Peter69_56]

So if the first hydro date on a cylinder is 1990 or later, youre good to go? Im looking at some used gear and have been wondering about the old alloy and how to avoid those tanks...

I found the easiest way was to buy new ones rather than old ones. And where possible i am going to steel. Resolves all the arguments and the resale value is much higher too.

 

[guruboy]

So if the first hydro date on a cylinder is 1990 or later, youre good to go? Im looking at some used gear and have been wondering about the old alloy and how to avoid those tanks...

If it is a Luxfer tank, then 1990 is a safe cutoff date. Catalina never used 6351 alloy.

However, I would also check the following-

1) Any local dive shop limitations
2) Any hydro test facility limitations
3) Any dive park fill station limitations

 

[DENFSEA]

see attach

 

[Eric802]

Wrong thread, sorry.