On Fri, 21 Nov 2003 17:49:15 -0600, Big John
wrote:

:Rich
:
:Said much better than I did. Tells it how it is.
:
:Big John

The water submersion while filling is for cooling, since the heat
could, in theory, weaken the tank if it got hot enough. If a tank
lets go the water won't do much to damp the explosion, I saw pictures
of a scuba shop after one failed (someone powder coated an aluminum
tank and destroyed the temper). Not much was left of the entire shop,
or of the owner.

IIRC, hydrostatic testing of a tank takes it to 5/3 of it's rated
pressure, and it can't expand more than 2% to pass.