We have a 3/4" vent line from equipment of SS304 (300#) material as per P&ID. After the Isolation valve (3/4") there is a spec break shown. The next specification stands for SS316 (150#) material. I want to clarify a doubt here. Why did the process engineer chose SS316(150#) instead of SS304(150#).
NOTE: Spec break is right after the socket welded isolation valve. i.e. on a welded joint
NOTE: Spec break is right after the socket welded isolation valve. i.e. on a welded joint