rstofer
Contributor
I have a pair of Luxfer tanks. One predates 6061 alloy and has been stored full for 20 years. The other is newer (1993) and stored full for 15 years. Both have passed hydro every 5 years and are due for testing in 2 years. I have no reason to believe the newer tank will fail. I have been told the cost to inspect the older tank has increased dramatically due to some change in the requirements for these older aluminum tanks. If so, I'll probably scrap it and buy a HP Steel 100. We'll see...FWIW,
I have two Dacor, Super 80 tanks (Luxfer, I think) that were purchased new in 1991 (6061?). Both were filled and remained filled between dives every time I surfaced. I last dove one of them in 1995 and it's still showing 3000 PSI. The other, I couldn't tell you when I dove it last, but it's been longer than that. I'd like to put an analyzer on them to test the O2 percentage just for fun, but I don't have one.
My OW instructor used the basic function of metal fatigue as an example of why they should be stored full. And I always have. So far those are the only two tanks I've owned, and of course, haven't had problems with them, but they're both WAY past due for a hyrdo and viz.
I've been careful about moisture in them, but they've been stored full for over 13 years each; will they pass?
Both were VI'd and cleaned for Nitrox this year without concern.
An aluminum 80 is on the order of $140. That works out to about $7 per year - a little more than the cost of 1 refill at Monterey. So what if it only lasts 20 years?
Richard