Panhandle A equation is used in the design of large high pressure, long transmission pipelines. The Panhandle A equation was originally developed from Reynolds numbers in the range of:
The average pipeline efficiency factor of 0.92 normally used in this Panhandle A equation was obtained from actual empirical experience with the metered gas flow rates corrected to standard conditions. The Panhandle A equation provides a reasonable approximation for partially turbulent flow; however, for fully turbulent flow, the Panhandle A equation is not realistic. In the fully turbulent region, the Panhandle B equation is recommended. Pipeline efficiency factors used in the Panhandle equations should be reduced for smaller pipe diameters. For large diameter lines, the efficiency factor may be as high as 0.98.
These Panhandle A and B equations suffer from the substitution of a fixed gas viscosity value into the Reynolds number expression, which, in turn, substituted into the flow equation, results in an expression with a preconditioned bias.
𝐹 − Transmission Factor
E – Pipeline Efficiency Factor
𝐶𝑓 − 7.2111
𝑄 − Flow Rate (FT3/day)
𝐺 − Gas Specific Gravity
𝐷 − Internal Diameter (in)
𝑄 − Flow Rate (FT3/day)
E – Pipeline Efficiency Factor
𝐶𝑄 − 435.87
𝑇𝑏 − Temperature Base (°R)
𝑃𝑏 − Pressure Base (psi)
𝐷 − Internal Diameter (in)
𝑃1 − Upstream Pressure (psi)
𝑃2 − Downstream Pressure (psi)
𝐺 − Gas Specific Gravity
𝐿𝑒 − Pipe Segment Length including Expansion (mi)
𝑇𝑓 − Gas Flowing Temperature (°R)
𝑠 − Elevation adjustment parameter
𝐶𝑆 − 0.0375
𝑍 − Compressibility Factor
𝑇𝑓 − Gas Flowing Temperature (°R)
∆𝐻𝐺 − Change in Elevation (ft)
𝐿𝑒 − Pipe Segment Length including Expansion (mi)
𝑠 − Elevation adjustment parameter
𝑉 − Velocity (ft/sec)
𝑄ℎ − Volumetric flow rate (scf/hr)
𝐷 − Internal Diameter (in)
𝑃𝑎𝑣𝑔 − Average Pipeline Pressure (psia)
Leveraging a Defined Fluid in PLTB (60 sec)