Dear Sirs,
I am designing a closed drains system. Please see attached a basic sketch! I want to know if it requires a blowdown valve or not.
The drum (design pressure of 10 barg) is connected to upstream headers at different ratings and the off-gas collected in the closed drain drum goes to a vapour recovery unit.
Because of this, the vessel has PSVs. My question is, although the drum normally operates at very low pressure (0.1 barg), does it require a blowdown valve?
My thanks in advance for your thoughts
Andy