Yes PER MINUTE, adding coffee helps one add all the proper terms
at the end!

And I was assuming constant temp, minimal moisture, etc etc to
calm down the calculations. In the case of a shop compressor
running a lower duty cycle, this is reasonable. Youcan get some
pretty weird numbers when you locate the compressor outside,
sucking outside air, then pipeing it inside.

The conclusion is the STANDARD cfm part. That implies the number
of air molecules (composed of O2, N2, Co2 and whatever else) is
conserved on both sides of the regulator.

Grant Erwin wrote:
Roy J wrote:

SCFM is STANDARD cfm ie one cubic foot of air at 14.7 psi


Perhaps you meant to write, "one cubic foot of air @ 14.7 psi per minute"?

SCFM on either side of a regulator is the same.


That's interesting. How did you come to that conclusion? Applying that to
my hypothetical situation of an airflow of 10 cfm @ 180 psi regulated down
to 90 psi, that would yield about 13.7 cfm at 90 psi. I suppose we're
assuming
constant temperature throughout.

Grant Erwin
Kirkland, Washington