i want to know that we are going to make a operator shelter near flare area:
What is recommended how far we have to make is any standard defined area around flare where we can not make any thing.
It's depended on the thermal radiation level around the flare during plant flaring. Refer to API-521 for the radiation exposure limitation for the personnel.
Why are you asking this in the pump engineering forum?
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)