Correction on Related Coefficient of Equations for Gas Transmission Pipelines

The 5 equations (Weymouth, Panhandle A & B, and so on) commonly used in gas transmission pipelines are introduced. By derivation, a new C_i is obtained from these equations. And at the same time a comparison is made with the old C_i given in a works by LI Changjun (2000), and a difference is discovered by the authors. By comparison between the new C_i and old C_i, the correction to LI Changjun's C, is made.