Yep, got a little egg on my face. I was trying to figure out what the cfm's would be with a given psi to see if I could use my 1.5hp emglo for an hvlp conversion gun that I'm getting from Jeff Jewitt. At first I thought simultaneous equations would give the answer. Wrong! Sometimes it's a bear getting old. Daughter popped in to visit. She's a 4th grade teacher. I asked her to check what I did and she immediately said I needed to use Boyle's Law. Blew me away that she could remember that from college over 10 years ago right off the top of her head. So here it is FWIW:
With the temp constant, the volume of a given mass of gas is inversely proportional to the pressure exerted on it.
Initial Pressure Final Volume
Final Pressure = Initial Volume
Applying that to my little 1.5hp emglo compressor:
124psi/29psi = X/3.6cfm
= 15.5cfm
Cfm's required for my new hvlp conversion gun are 6.6cfm per specs..