<p>This paper presents a comprehensive failure analysis of an AISI 316L stainless steel dechlorination system tube, which experienced premature rupture at a petrochemical facility. The study investigates the causes of the failure through macroscopic examination, chemical composition, microstructure analysis, scanning electron microscopy, energy-dispersive x-ray spectroscopy (EDS), and ultrahigh-depth-of-field microscopy. The results indicated that chloride ions present in the regeneration flue gas caused the dew-point corrosion and stress corrosion cracking. It leads into the formation of pits and cracks which resulted into the fracture of the tube.</p>