Modified Panhandle Flow Formula

E = efficiency factor for flow, use 1.00 for new pipe without bends, elbows, valves and change of pipe diameter or elevation 0.95 for very good operating conditions 0.92 for average operating conditions 0.85 for poor operating conditions 

T = flowing temperature, R Z = gas deviation, compressibility factor T = base temperature, (520 R) 

G = gas specific gravity Z = compressibility correction term P = pressure, psi, absolute PD = base pressure, (14.73 psi, absolute) 

E = efficiency factor, which is really an adjustment to fit the data f = fanning friction factor qDS = flow rate, SCF/day 

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