Calculation of Minimum Pipe Diameter in Designing a Gas Transmission Line

Pipe diameter is one of important options of designing a long distance gas pipeline. In order to select effectively pipe diameters in designing a gas pipeline, the concept of minimum pipe diameter is presented. Based on this concept, formula of minimum pipe diameter and its simplified form are deduced. According to design throughput, design pressure, average gas temperature and gas compressibility factor, minimum pipe diameter can be calculated. The results from these two formulas agree with actual pipelines. Using the first formula, elective pipe diameter limit is bigger than using the simplified form and economically critical velocity has a potential to lower to be less than 10m/s. The simplified form is suitable for selecting diameter quickly and roughly. These formulas provide a solution to select pipe diameter.