On Tue, 23 Dec 2003 15:01:54 -0600, "Tim Williams"
wrote:

"jim rozen" wrote in message
...
The regulator is a feedback controlled valve. ... it does not get
perceptibly hot.

Indeed because expansion is occuring inside the regulator,
under certain conditions, they may start to chill preceptably.

So where does the heat go? I'm going to guess that compressive systems
such as this act as heat pumps, thus all the heat goes back to the
compressor, while cooling occurs at the tools and regulator. Eh?

Tim

It can be a tricky one to grasp at first. This is an adiabatic expansion. No
external work is being done and no heat is being added to, or taken from, the
gas. The reason it cools down is because it is doing work on _itself_ during
the expansion.

Mark Rand
RTFM