All,
I need to calculate the flow through a 2" piece of pipe containing gas phase benzene at 200F and 15psig. At the end of the 2" pipe is a 16" flare header that runs at a pressure of 1 psig. The pipe is SCH 40 carbon steel, new, and is about 30' long. I am attempting to use the compressible flow formulas in Crane TP 410 to accomplish this. I have tried the complete isothermal equation, simplified isothermal equation, Weymouth and Panhandle (which really don't apply), and modified Darcy equation, but I seem to be getting different answers depending on whether I am calculating a mass flow rate vs a volumetric flow rate, and I cannot find the error in my calculation anywhere. I know that this flow is not really isothermal, but I need some sort of approximation, so that's where I am starting. In particular Equations 1-28 and 1-29 should result in the same answer, but even those don't match up! Any help appreciated. Please see attached spreadsheet for calcs.