In article , "AL"
wrote:

I'm afraid I don't understand why the tank would go airborne. When I open
the drain valve with air still in the tank, my compressor doesn't hit the
ceiling. I'm thinking about a weak spot maybe 0.5 to 1" in diameter, sized
appropriately for the pump.

What does the assembly weigh and what is the burst pressure? If the
burst pressure is 300 psi and the disk is one inch in diameter, the
thrust at the moment of burst will be (Pi (0.5)^2)(300)= (0.785)(300)=
236 pounds. The impulse (integrated thrust) will be proportional to
tank volume.

Anyway, this thrust is enough to make most compressors move.

Joe Gwinn