Session: DA-15-02 Coke Drum Materials Considerations

Paper Number: 153394

153394 - Coke Drum Bottom Head Flange Distortion, Root Cause & Solutions 

Abstract: 

Bottom head flanged joints are a critical component in the successful operation of a coke drum. These large diameter joints are expected to maintain integrity during service while exposed to significant thermal transients encountered during the drum cycle. Plant engineers can find joints that were originally flat and reliable have become distorted and prone to leakage over time. Significant thermal transients and poor flange geometry can result in flange “ovality & cupping” making disassembly and reassembly of bottom un-heading devices (BUD’s) during scheduled maintenance intervals problematic, as flanges are no longer within tolerance and bolt holes no longer align. This phenomenon appears to be restricted to the drum flange, with adjoining valves being unaffected. This paper will explore why these joints change over time, identifying the root cause and offer solutions to keep a distorted flange leak-free for another production cycle. A case study will be discussed, and FEA results shared, explaining the fundamental behaviour of these unique bolted flanged joints that experience uneven gasket loading in both the circumferential and radial direction due to thermal transients. Gasket design is an important consideration with gasket behavior examined using FEA techniques. Practical solutions including gasket redesign and improved assembly practices will be offered along with recommendations for new flange geometry.

Presenting Author: Mike Horstmeyer Phillips 66

Presenting Author Biography: Mike Horstmeyer has worked in the refining and petrochemical industry for the past 12 years. He has spent time in maintenance, process engineering, production planning, and mechanical engineering at multiple integrated operating companies. He enjoys working with teams to develop novel solutions to persistent and complex mechanical integrity challenges. Mike holds a Bachelor of Science in Mechanical Engineering from Purdue University and an MBA from Louisiana State University.

Authors:

Mike Horstmeyer Phillips 66
Ann Corcoran Phillips 66
Antonio Seijas Phillips 66
Alex Berry Integrity Engineering Solutions Pty. Ltd.
Warren Brown Integrity Engineering Solutions Pty. Ltd.