The only certainties in life are death, taxes, and that delayed coking drums crack. Every year at RefComm®, we have healthy discussions with experts from around the world on this phenomena. I believe we are inching ever closer to resolving this issue once and for all. For those who suffer with cracking drums, this resolution cannot come soon enough. Until then, there is a great solution: weld overlay in problem areas.
OK… many of you are thinking this is not new information. Yes, you are correct but…what is new is some long range studies that are demonstrating how weld overlay repairs have lasted 10+ years, 3-5x longer than other repair strategies. Mr. DuPlessis’s presentation with Dr. Samman, Successful Reversal of Deterioration in an Old Set of Coke Drums, reviewed his work at Suncor Energy with repairs, side entry to dual feed conversions, and R&D jointly conducted with Alberta University. Long story short, weld overlay can have a 10x increase in the fatigue life of the coke drum. WOW!
Robot welding is required. Manual overlay with stick welding just does not have the quality control of the machines even with the best qualified welder.
Struggling with replacement of your coke drums? There maybe some more life in that steel with a new coat of Inconel. If you are already working down the path of getting new drums, why not consider just adding weld overlay from the start. Yes, it will add cost but a risk and life cycle analysis with this new data may change your mind about the long term benefits.
2 responses to “10x Life Improvement in Coke Drum Life Using Weld Overlay – Highlights from RefComm® Galveston 2017”
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My Question is this. Has anyone out there experimented with different Types of overlay welding wire? The type of wire that we are using seems to not be the best answer. We are having issues with the toe of the weld failing where it bonds to the cladding. It fails after years of service though. I wonder if we should experiment with a few different wires on our next outage? Something with more ductility i think might be the answer as the corrosion performance is flawless. The Cokers i am referring to are pictured above.
Yes, we have experimented with a couple of welding wires. For external repairs, we can use a base metal matching wire. For interior repairs, 625 is the most effective we could find. The toe of the weld is a geometric discontinuity and a joint of three different metals with three different mechanical properties which makes it susceptible to higher stresses. If we don’t use adequate specifications and ensure that they are properly implemented, premature failures will certainly occur. That is why the design, implementation, and inspection of these repairs are critical to their long-term success.