On Sat, 11 Sep 2004 23:08:43 +0000 (UTC), "Don Foreman" wrote:
I think the difference in gammas tells the tale.

I'm about 4000 miles from my Machery's Handbook just now, but I think change
in pressure and volume will dictate outlet temp as fn of input temp so
actual inlet temp for a given adiabatic expansion is immaterial --
providing of course that steam does not condense. Outlet temp can be
above or below ambient.

Outlet temp can't be below ambient unless external work is applied to
the piston to expand the gas below ambient pressure. Otherwise, you'd
be violating the Carnot limit.

Gary