Industrial plants in the petrochemical sector usually require a large number of complex piping systems, which is basically due to the need to transfer and process fluids under different pressure and temperature conditions in their production operations. These systems are subjected to the simultaneous action of permanent, occasional, constructive and transient loads. Under these conditions, they present deformations, normal and shear stresses, in addition to transferring loads to their attachment points (equipment and supports). These efforts must be avoided or mitigated to values below the resistance of the tube material through a series of design strategies, among which the configuration of a more flexible layout and the inclusion of restrictions to direct the expansion of thermal radiation stand out. In this project, Caesar II, a comercial piping design software, was employed to perform the flexibility analysis of a process piping that connects the gas outlet nozzle of a two-phase separator vessel to a PIG launcher present in a primary natural gas processing plant.