"Donna Ohl, Grady Volunteer Coordinator" wrote in
message

If the pressure is 150 psi inside the tank, what is the pressure the hot
water is coming out? Is it at 150 psi while the cold water remains at 80
psi? I find that hard to believe, empirically.

Donna

It is whatever it is until you open a valve and it will be no more than the
cold water behind it. Static pressure is probably not much more than the
dynamic anyway given the low temperature. Water does not compress well so
it is very easy to relieve pressure so there will be no dramatic "poof" when
you open the tap.

If, however, the gas ran wild and made steam you could have much more
pressure and a violent release.