Steady-state gas flow in pipes

New general flow equations of simple form are developed to account for the pressure drops due to friction, elevation and kinetic energy change. Simplified forms are also presented for new flow equations fur gas flow in pipelines or wells where the kinetic energy term can be neglected. The new general flow equations and their simplified forms are compared with the widely-used AGA equations and tested with field data. Results show that the new equations make excellent predictions of flow rates or pressure drops, and that they are applicable over a much broader range of gas types and gas flow rates than the AGA equation and old simplified flow equations. In addition, different empirical explicit correlations for the Fanning friction factor are compared. It is found that different correlations give quite different values of the friction factor. For smooth pipes, modified 1/9th power law, Blasius, Drew et al., and Panhandle equations are recommended for different Reynolds number ranges. For rough pipes, Serghides (I) and (II), Zigrang-Sylvester (I) and (II), Chen, and Haaland equations can be employed with confidence. Other friction factor correlations reported in the literature should be avoided because they can result in large errors.