Pipe Flow Calculations Forum

I'm a gas piping contractor, and I have no problem sizing a system using charts. I have a fair amount of understanding of sizing, but these calculators always throw me. I just need to know what size pipe to use for a 2 psi natural gas piping system with a longest run of 1000 feet. It will all be done in Schedule 40 black iron. If anyone has an answer that'd be great, but even better, I'd like to learn how to do this myself. Thanks.
Anthony

You should tell me the flow rate that you need so the diameter can be calculated. 2 psi is small pressure so you should use pressure drop calculator on:
http://www.pipeflowcalculations.com/pre ... /index.htm.

Or if pressure drop is small and just want to have pipe diameter for given flow rate than you can use pipe diameter calculator at:
http://www.pipeflowcalculations.com/flowrate/index.htm.

Anyway, both calculators are for not compressible flow, but with 2 psi, flow can be calculated as not compressible, with very small error if you enter density on given pressure and for atmospheric pressure you have for methane rho=0.717 kg/m3, and at 2 psi it is 0.8145 kg/m3.

I have attached one sample of calculation for you.