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Fatigue Life / Reliability Consideration during Field Repair of Coke Drum / Piping

Presented By

Reliance Industries Ltd. - Umakanthan Anand

Amec Foster Wheeler - Tej Chadda


Amec Foster Wheeler & Reliance Industries LimitedThe aging coke drums and connected piping in delayed coking unit, DCU, experience cracks commonly at skirt junction and critical welds due to low cycle thermal fatigue and/or vibration induced fatigue. These aged vessel and piping components require field repair for continued operation.
Various reasons for these fatigue cracks are due to the original design of coke drum and piping not being fatigue resistant, thermal operation and gradient being too severe, fabrication of the vessel and piping not being fatigue resistant.

The life management, reliability, and safety consideration of coke drum and piping require consideration of fatigue and stress risers during field repair. The service life, reliability, and safety of these components require fatigue life consideration during the field repair instead of continuing simply with monitoring cracks and repairing them with the original design and continuing to operate with original thermal operation practice of coke drums.

Case studies will be presented to demonstrate implementation of fatigue life and reliability improvement consideration in field repair of coke drum skirt junction and overhead piping welds and optimization of upgraded fatigue resistant repair design methodology and thermal operation/gradient optimization.

low res ChaddaTej Chadda is Director, Technology Technical Services at Amec Foster Wheeler, Houston, Texas. He has worked for FWUSAC in Houston, Texas, USA for over 19 years out of total of 43 years industry experience. Tej has stress analysis, FEA and field experience in Delayed Coker Unit and FCCU application.


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