Hello, Piyush – that is a very complicated question but let’s try to unpack it a bit….

+ Maintaining draw temperatures is typically done by adjusting pumparound (flow and TC around steam gen) and wash oil flow and reflux.
+ End point is a bit variable in measurement so lets talk about 95%Pt…. HCGO > 850F is getting pretty heavy and likely to cause issues downsteam. LCGO, it totaly depends on your tower configuration.
+ HCGO underpan temperatures >750F will likely cause coking but dead zones with temps >700F could also be a problem.
+ Fractionator layouts and configuration vary significantly across licensors. In fact product seperation and recovery if one of their key selling points.

What values are you seeing for the above information? Who licensed your coker?