Prediction of remaining life of a FCCU reactor plate

Evaluation of mechanical properties is a powerful tool for investigating and assessing the performance of service exposed materials. The trends recently observed in service exposed (32 years) plain carbon steels used as a reactor vessel material in a petrochemical plant have been highlighted in this paper. Health assessment of both base and welded joint was made using impact tests at room temperature, destructive accelerated stress rupture and tensile tests at different temperatures, and some nondestructive tests. From the stress rupture tests it could be concluded that a life of more than 10 years at the hoop stress level of the material can be obtained, provided no localised damage in the form of cracks or dents have been developed. It is recommended that a health check should be carried out after 5 years of service exposure at 485°C.