As I say up-thread, the important issue is the length of fracture that you can create with your explosion, and whether that penetrates far enough into the volcano (cylinder) to increase the stress level in the remaining material to the point at which the fracture will continue to propagate after the fracture initiating event (explosion).
Understanding fracture propagation is a pretty basic part of materials science, and (probably) fundamental to many courses in mechanical engineering. (I'm a geologist, and we covered it un structural geology. But mechanical engineers of my acquaintance when I was a student studied the same material at a different part of their course. They also did a bit of geology - you need a bit to understand what you're building foundations in/ on.)
Try https://en.wikipedia.org/wiki/... for a starter.
Incidentally, I've seen a charged compressed air cylinder fall 10m and land on rough boulders. With about 250bar of air inside, we leapt for shelter, expecting it to go off like a bomb, but it didn't. So, somewhat gingerly, the person who dropped it came down the rope and carried on "Sherpa-ing" it into the cave where the diver was going to use it. We gave the a hydraulic test the next day, and it passed, but with that dent in it, it was never going to pass a visual inspection, so it was relegated to the back of the club's air bank.
I don't recommend treating cylinders like that, but they're not as delicate as you'd think. Well, not the steel ones ; I don't know anyone who uses aluminium tanks.