Nature and Importance of Thermal Damage in Refinery Equipment: In refineries, metallic equipment is constantly subjected to harsh operating conditions. When this equipment suffers thermal exposure due to fires, uncontrolled temperature excursions, insulation failure, or direct flame impingement, a series of complex changes occur. These changes are far more significant than what is visible to the naked eye. While discoloration, surface scaling, or initial scorching are typically the first indicators, the impact of temperature on metal primarily manifests in the