In article ,
says...
In article , Richard J Kinch
says...

It should be obvious, anything that impedes the
flow of compressed air has got to be robbing power.

This is fundamentally incorrect. An orifice that
restricts flow does not disipate power. Consider
an expansion valve in a refrigeration system.

Your approach also fails at one end point, where
the restriction prevents only a tiny bit of flow,
almost none. YOu sould say this is the *lossiest*
case - but it isn't.

Unless you're treating the tiny orifice as a leak, it is
indeed the "lossiest" case. For a given flow, greater delta
P across the orifice results in a greater loss.

Ned Simmons