Pipe Flow Calculations Forum

I'm trying to determine the time required to fill up an 8,000 foot 1.25" pipe. The pipe is closed on one end, with a connection to a higher pressure at the other. I've tried using the equation: P1^2 - P2^2 = Z*R*T... etc. I end up with such a low flow rate (<20 CFM @ 0 deg F) that it makes me t...