In article , Gary Coffman says...

10 CFM of course. As you note, mass is conserved,

But there is twice the mass flow in the upstream
(hp) side in teh example. In one minute, 10
cu feet of air at 180 psi flows in. If you count
the number of atoms (mass) you will find that the
same number come out the downstream side at 90
psi. They just take up more room at a lower pressure.

I would say that if 10 cubic feet of atoms at
180 psi flow in, then 20 cubic feet of atoms
will flow out, at 90 psi.

PV = PV, universal gas law and all.

PV = nKT

n is not varying, same number of atoms.
KT is constant if you allow the gas to
come to thermal equibrium at the outlet of
the regulator.

So P1/P2 = V2/V1 and all.

Jim

Jim

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