Why 15 psi max on pressure cookers?

I don’t understand what is meant by “pressure stored,” even though experientially that is as good a way as any to describe it. But it seems kind of just-so-ish.

Before I go off to Wiki “compression,”–which is where I think I should go–after which I’ll probably come back anyway, can someone put “storing pressure” into some more discrete terms?

Also, I’m guessing here, as well the thermodynamic aspects under discussion here, does the term “continuum mechanics” apply to the area of physics I think I’m getting at?

  • off to check what c.m. means while he’s there… *