Pipeline Flow Calculator

Flow Rate and Gas Velocity both report zero. Gas only flows from higher to lower pressure through a pipeline, so if Outlet Pressure is at or above Inlet Pressure there's no positive pressure differential to drive any flow -- this calculator treats that as zero flow rather than a negative or undefined result.

In the Panhandle A equation this calculator uses, Pipe Diameter enters the formula raised to roughly the 2.6 power, meaning even a modest increase in diameter produces a much larger increase in Flow Rate. This nonlinear relationship is why pipeline capacity upgrades often focus on diameter rather than pushing for a bigger pressure differential, which only affects flow by a square-root relationship instead.

Not necessarily in this calculator. Gas Velocity is Flow Rate divided by the pipe's cross-sectional area, and while cross-sectional area grows with the square of Pipe Diameter, Flow Rate itself grows with roughly diameter to the 2.6 power in the Panhandle A equation -- so increasing diameter alone (holding pressures fixed) actually increases Gas Velocity somewhat, not just total throughput.

The Panhandle A equation ties Flow Rate to the square root of (Inlet Pressure squared minus Outlet Pressure squared), not to Inlet Pressure directly, so it takes a proportionally larger increase in Inlet Pressure to produce a given percentage increase in flow, compared to the near-linear effect of Pipe Diameter. Raising Inlet Pressure does always increase Flow Rate, though, as long as it stays above Outlet Pressure.