Failure Analysis of Fire Tube Sleeve of Heater Treater

Abstract

The fire tube sleeve of a Heater Treater that was installed in an Oil and Gas processing unit ruptured after a service life of around 15 years. The detailed failure analysis was undertaken on this failed Incoloy 800 (UNS N08800) fire tube sleeve to ascertain the causes and mechanism of failure. The various studies indicated that the exposure of the sleeve to excessive temperature resulted in internal oxidation corrosion and caused of the failure. Additionally, Incoloy 800 is susceptible to sensitization in the temperature range of 540-1095°C which did occur and resulted in intercrystalline cracks causing grains to fall out of the metal leading to a thickness reduction. The main causes of failure were overheating and the resulting microstructural evolution and recommendations to prevent such failures in future are presented.