Hi.
We have a column system which has a PSV on the overhead vapor line.
PSV protects column and overhead drum in external fire case.
There is no block valve between column and drum.
However, overhead drum has inlet with deep pipe.
Someone told me that PSV cannot protect overhead drum in external fire case
because inlet pipe is submerged in liquid. Vapor cannot go through inlet line when fire case.
Equalizing line of drum is too small to relieve the external fire relieving rate.
Is there other solution to protect column and drum without adding PSV or increasing equalizing line size?
Thank you.