Optimising reformer tube life by applying advanced inspection and remaining life assessment technology

Centrifugally cast materials, namely HK40, HP Modified, and Micro-Alloy materials, are used for tube materials in steam reformer tubes. The material undergoes various stresses resulting in damage which can manifest itself in several ways. The quantification of damage is of vital importance if tube life is to be predicted accurately. A comprehensive inspection system has been developed to assess the exact degree of damage. The technology utilises several NDE techniques, including ultrasonic and eddy current examinations. The combination of techniques provides valuable data for the prediction of the remaining life of tubes. Customised software for remaining life prediction directly utilises the inspection information, together with plant operating parameters, to provide a methodology for managing tube life scenarios. Field experiences and findings are discussed in the paper.