Dear experts
As you can see in attached P&ID,there is a methanol storage tank with N2 blanketing system.
Tank design pressure=150mmH2O
Psv set pressure=120mmH2O
PCV set pressure=100mmH2o
Max ambient temperature=60°c
Our engineering department are going to change PCV set pressure to 50mmH2o.
Is it ok to decrease PCV set pressure regarding to mentioned conditions?
What parameters should be considered in order to determine the correct set pressure for PCV ?
Is there any relevant reference or standard?
Regards
Rohollah