Manual depressurization line
Manual depressurization line
(OP)
In most of projects, isolation philosophy specify a vent valve between ball and globe valve in manual depressurization line, however sometimes there is not such valve. Can you explain purpose of such vent valve?



RE: Manual depressurization line
Top one is clearly higher pressure and has DBB on the prv inlets. Bottom one is 8 bar and only single valve isolation
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RE: Manual depressurization line
If yes, a drain valve may not be needed as it's a sloping line.