I was thinking about interesting powder metallurgy method, hot isostatic pressing. Often thick steel walled vessel is required increasing costs and decreasing the prevalence of this technology.
This led me to consider say several metal spherical concentric tanks. I wonder if the inner most tank is at very high pressure more so than the metal wall could handle but was counter acted mostly by a second concentric tank pressurized nearly to the same pressure but slightly less, and so on so forth until finally the outer most tank was low enough pressure to be contained.
I'm not really sure of the net forces? Would there just be large compression forces on the tanks? Would there be a large net force inwards or outwards? I ask because it would be interesting if say I had two balloons and everything worked out such that say I had a 99% chance of rupturing balloon A at pressure P_1 but it balloon B had less than 1% chance of rupturing at pressure P_2 and I found both had low chance of rupturing at respective pressures with balloon A contained inside balloon B. Maybe this help to understand the idea I wonder about, perhaps it is a fallacy I'm not sure.