Shaileshkumar Oza - Reliance Industries Limited
Jaymin C. Patel - Reliance Industries Limited
Coke drums in the first refinery at Reliance Industries have been in operation since 1999. The refinery had a total of eight coke drums installed with bottom feed entry design. Post commissioning, these drums were operating in 22- to 24-hour cycles; later the cycle time was optimized to 14 hours. In 2007, the first through-wall crack was observed in all eight of the coke drums at the skirt to knuckle junction. Further severe bulging in the shell courses and cracks in the weld seams were also observed due to severe thermal stresses and aging. After multiple rounds of inspection, monitoring, and repairs, it was decided to replace these drums with new design drums. Recently, these drums have been replaced with new coke drums having Centre feed devices.
To sustain integrity until the drum replacements, various studies were carried out to predict drum behavior; state-of-the-art repair methodologies were tried and implemented for internal and external repairs.
This presentation outlines the 20-year journey of the coke drums in Reliance, starting from the commissioning through to their replacement. It focuses on the various types of cracks occurring in a coke drum, repair methodology for through wall and bulge overlay repairs, inspection techniques for crack identification, inspection frequency, use of advance inspection techniques like acoustic emission testing, thermal performance monitoring technique, and laser scanning, etc.
Shaileshkumar Oza is the Head of Reliability Static at Reliance Industries. He has been with Reliance for 18 years. He is a certified API inspector for pressure vessels, piping, and tankages. He has presented many technical papers in India and abroad at various technical conferences.
Jaymin Patel is a Corrosion and Inspection Engineer currently responsible for the Coker units at Reliance Industries. He has 10 years of experience working in refineries. He has been associated with Reliance for the past 5 years. He is a certified API inspector for pressure vessels and piping.