Emerson Sempell PSRV VS99

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SEMPELL MODEL PSRV - PRESSURIZER SAFETY RELIEF VALVES
TYPE VS99 PILOT OPERATED
During normal operation, the valve is closed.
Alldiscs of the valve are closed. The solenoids
are not energized.
FUNCTION DMS 6 (energized open principle)
Solenoid 1 De-energized
Solenoid 2 De-energized
Disc 1 Closed
Disc 2 Closed
Disc 3 Closed
Disc 4 Closed
Chamber A System pressure
Chamber B System pressure
Chamber C System pressure
Chamber D System pressure
Chamber E System pressure
If both solenoids are energized, pre-pilot discs
2 and 4 are lifted. Therefore the pressure in
chambers E above the discs is relieved and
discs 1 and 3 can open. The upward motion
of discs 1 and 3 is supported by the system
pressure below discs 1 and 3.
Solenoid 1 Energized
Solenoid 2 Energized
Disc 1 Closed
Disc 2 Open
Disc 3 Closed
Disc 4 Open
Chamber A System pressure
Chamber B System pressure
Chamber C System pressure
Chamber D System pressure
Chamber E Pressure relief