Panhandle B equation is used in the design of large high pressure, long transmission pipelines.
The Panhandle B equation is considered suitable for Reynolds numbers from:
𝑅𝑒 = 4𝑥106 𝑡𝑜 40𝑥116
The equation can be adjusted through the use of an efficiency term that makes it applicable across a relatively limited range of Reynolds numbers. Other than this, however, there are no means for adjustment of the equation to correct it for variations in pipe surface. Adjusted to an average flowing Reynolds number, the equation will predict low flow rates at low Reynolds numbers, and high flow rates at high Reynolds numbers, as compared to a fully turbulent flow equation. Efficiencies based on the Panhandle B equation decrease with increasing flow rate for fully turbulent flow. The efficiency factor, E, used in the Panhandle B equation generally varies between about 0.88 and 0.94.
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 − 16.7
𝑄 − Flow Rate (FT3/day)
𝐺 − Gas Specific Gravity
𝐷 − Internal Diameter (in)
𝑄 − Flow Rate (FT3/day)
E – Pipeline Efficiency Factor
𝐶𝑄 − 737
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)