Posted: Thu Oct 11, 2012 11:49 pm
Using the Orifice Plate calculator to range an orifice plate for N2 service. The density of the gas that is calcuated doesn't seem to correlate with what I've calculated based on Temperature of 25 C, gas constant of 297 J/kgK and pressure of 2.07 bar. I calculated a density of 3.48 kg/m3 but the program states the density is 2.34 kg/m3. Finally determined my mistake was inputing gage pressure and not absolute. Did I miss something that tells us to use absolute pressure or is that just understood in gas flow and I'm being slow on the take-up?