Simplified Creep Assessment of Catalyst Tube

Creep monitoring and assessment of catalyst tube is critical to avoid catastrophic
failure. Although there are many creep assessment methodologies available, the
methods not only costly but also sophisticated. Thus, there is a need to develop a
simplified creep assessment method to assist plant engineer. The main objective of
this study is to develop a method of Non-Destructive Testing and microstructure
study methodologies to monitor creep in catalyst tube. A sample of damage catalyst
tube has been taken from PETRONAS Fertilizer Kedah and the tube ruptured early
before it reaches the expected life of the tube and suspected due to creep damage
Ultrasonic testing and metallography study has been chosen as the methodologies to
monitor the creep on the catalyst tube. By using ultrasonic flaw detector, the
ultrasonic velocity has been determined. While by doing metallography study, the
microstructure is obtained from optical microscope and hardness value from
microstructure Vickers hardness. The result showed that there is decreasing in
ultrasonic velocity values with increasing values of grain size. Besides that,
increasing of hardness value also associated with the precipitation of carbide. Thus,
the objective for this study is achieved by monitoring the velocity in ultrasonic
testing and the microstructure for reformer tube evaluation. This technique has a
potential to assess the creep damages and remaining life of the reformer tube.