The aim of equipment depressurization in an upset operation is to maintain the internal pressure of the vessels and piping below the rupture pressure, as the material ultimate tensile strength decreases with temperature tolerance beyond the acceptable limit. Depressurizing also causes to decrease the extent and duration of leaks that may occur as a result of mechanical failure. In the case of ignition and fire, a depressurization system can limit the fuel supply to the fire. In addition, the main objective of the pressure relief facilities is to keep personnel safe as well as equipment exposed to overpressure conditions that happen during process upsets. This thesis is intended to examine the modeling of depressurization in different scenarios, evaluate flare flame distortion and heat radiation as the most important consequences of this event, and consequently offer some recommendations for the design of any gas plant that has potential for overpressure.