If you don't break it, a tank should last forever. Resealing really isn't a big deal. All but one of my tanks were bought as leakers for pennies on the dollar. From 20 to 180 gallons.
I could sled ride in that thing and break my neck before that tank.
. They are built to withstand gunshots I think. .
But my grandfather have his tank for even more and it's not leaking. I'm doing maintenance on his tank because he is 73 years old.