510 inspection of a CAT structure

[90harley]

To all; I am 2nd year API 510 inspector an starting a new turnaround next week. On this job I will be working the Cat structure. My past experience is towers and drums with little to no experience on the structure. Can someone point out some of the main components of the structure (3rd stage separator, reactor ext..) and the inspection back ground. The discovery work is complete so for the most part it will be repairs but I would like an idea of what I am walking into. Thank you!!

 

[Duwe6]

Look for grooving due to entrained abrasive - cat is usually alumina dust with 'magic' additives. Grooving will be just past ells and nozzles. Look for stress and creep problems - cat crackers run HOT. Assume any repair, weld or basemetal is a crack, and personally verify complete removal prior to welding. This time of year, be present at the start of welding, checking for proper preheat; most cracker parts are thick and w/o preheat will yield Underbead cracking in repair welds. This means start of shift, break(s) and lunch. "If you don't care enough to climb up and check it, how can you expect the welders to care about getting it just right?"