Q & A > Question Details
In the FCCU, the main fractionator bottoms slurry settler typically has a pressure safety valve (PSV) for over-pressure protection. Is this PSV sized to relieve pressure from water vaporization that might occur during start-up as the system is heating up?
30/09/2007 A: Vladimir Gagic, Oil Refinery Pancevo, vladimir.gagic@rnp.co.yu
It is more likely that PSV are designed to protect slurry settler from overpressure from other causes. Water, if present, should be drained before startup or during initial phase of startup.
To be sure of this you can check your PSV specification sheet, if they are designed for vapor or liquid flow.......