Switching heater change pumps in a coker is always a rush.
- How bad did we bounce the heaters?
- Everyone at the ready in case the check valve doesn’t hold.
- Ready to switch back if the spare has problems.
We all know that when working with the heart of a unit you need to be careful. The suction pressure valve is 50# at 720 degrees and the discharge is 575#. After a routine switch of pumps–heater flows looked ok, spare running fine—we went ahead and got the main pump set in stand by. As the ground operator opened the warmup valve (discharge above check valve to suction side), the valve and piping broke off. He was holding the valve as he ran from the pump area. Needless to say, we had a large fire. Remotely we closed the suction and discharge valves for both pumps.
- Unit down
- Heater’s blown
- Fire team everywhere
- Wow, what a night!
Root cause: Wrong metal used for warm up piping.