heh heh heh... story of my life. DeltaP is somebody's change in pressure but I'm sure you know that already. What's flowin', what's it goin' around, and what's the start/end pressure are good things for an engineer to tell ya. Or give you a chart of some significance.
I did work it out... The spreadsheet he sent actually has the correct equation embedded in it. So I pulled it out, translated the Excel codes into the different variables, wrote out notes explaining to myself what the variables are, and discovered that he hasn't sent me the table of orifices, so I can't finish this stupid equation anyway.
Actually I'm pretty proud of myself, because I can follow this stuff, more or less. See what waaay too much college math does to a girl?