Item:

• HK40 support system in a catalytic reformer heater at a UK refinery

Problem:

• Two of the eight high temperature (980°C) radiant section supports had failed, leaving the remaining six to support the full load
• Supply of replacement HK40 material has a lead time of two months

Objective:

• Fitness for service and remaining life assessment to consider whether the surviving supports could sustain the load until a convenient time for replacement

Approach:

• Removal of failed supports from operating heater
• Metallographic examination revealed failure to be by creep
• Creep life assessment predicted that the remaining life of the current supports, subjected to the higher support loads, to be a matter of days, or even hours

Solution:

• 24 hour monitoring of remaining supports instigated
• Plant immediately put into condition for most economic safe shutdown
• An alternative material to HK40 proposed for support replacement and new supports constructed in days

Outcome:

• Failure of third support two days later
• Heater immediately shut down safely

Benefits:

• Catastrophic failure of heater, with associated consequential loss, avoided
• Alternative solution to existing long lead time material procurement
• Safe shutdown and monitoring processes identified and implemented