Reliance is operating 2 world’s largest Cokers ,each @160KBPSD-8 drums, at Jamnagar India. We are operating at 13 hrs coke drum cycle.
We have interlocked all coke drum and blowdown column valves using the DCS software which doesnot require a separate PLC etc. This has been very reliable safety interlock for the last 7 years of operation.
We use Velan valves (mostly ball valves ) with motor actuators and these are very reliable.
Wilson Snyder switch valve could also be automated as done way back in 1993 in KNPC cokers (Hydraulic automation ).