Item: •Coke drums fabricated from 1CrMo steel

Objective: •To determine the probability of failure as a function of operating cycles, for input to a risk-based plant management programme
•To obtain the optimum balance between drum life and process performance

Approach: •Review history, install strain gauges and thermocouples
•Analysis of operating data
• Probabilistic assessment of fatigue crack initiation and growth
• Modification of operating cycle in the light of the observed behaviour
•Refined assessment based on revised operation

Benefits:
•Risk-based quantification of drum life
•Improved life and availability by understanding and controlling the effects of operational parameters
•Optimised operation, allowing improved performance whilst minimising damage-initiating events

Publication: Church, J.M, Lim, L-B., Brear, J.M , Jarvis, P., and. Lant, R.P.D.
“Crack growth modelling and probabilistic life assessment of coke drums operating under fatigue conditions", Second HIDA Conf ‘Advances in Defect Assessment in High Temperature Plant’, MPA, Stuttgart, Germany, October 2000. Paper S8-2, Int J Pressure Vessels and Piping, Vol 78, Issues 11-12, Nov/Dec 2001, pp.1011-1020