W. David Wang: About the Author
Shell Global Solutions

This paper covers most of the common (and some not so common) types of NDE methods for heat exchanger (HX) tubular in-service inspections. In addition to noting some of the various advantages and limitations with these methods, the paper covers heat exchanger tubular inspection planning, data analysis needs, a consequence rating method for scheduling inspection and bundle renewals, tubular cleaning methods and tubular inspection technician qualifications.

Hydrogen-induced cracking is a damage mechanism commonly observed in the petroleum refining industry [1, 2]. The damage appears as laminar cracks and blisters, which can link up in the through-wall direction to form stepwise cracking.

Nelson Curve changes in the late 1980's provided cause for Shell Oil Company to look at more reliable NDE non-destructive evaluation methods for assessment of materials/equipment in high temperature hydrogen service. The primary change motivating Shell was the lowering of the C-0.5 Mo steel Nelson Curve to the carbon steel level.