The aim of this research was to study the behavior of the equation of Swamee-Jain in the most varied situations of conduction of water in pressurized systems. A software was developed to accomplish simulations varying the internal diameter of the pipe, mean velocity of flow and absolute roughness of the pipes. The base of comparison of the study was the most employed equations in the calculation of the of friction factor of the universal equation of Darcy-Weissbach, respecting the respective drainage regimes and limitations. For the turbulent regime in flat conduit, it was observed that the equation of Swamee-Jain presented differences of values of f in relation to the specific equations, needing, for a better precision, a correction factor. For the other drainage types the agreement was considered satisfactory
hydraulic; loss of load; irrigation