Emerson Sempell PSRV VS99, Manual

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9
VS99
D
N
50
D
N
25
D
N
15
DN200
DN150
VS99 VS99
DN400
D
N
20
0
D
N
20
0
D
N
15
0
D
N
15
0
D
N
15
0
DN25
D
N
51
D
N
25
DN25
D
N
25
D
N
25
D
N
51
D
N
25
DN150
DN25 DN25 DN25
D
N
15
D
N
15
D
N
15
D
N
15 D
N
15
DN25 DN25
DN25
DN25
DN25
DN25 DN25
D
N
25
D
N
25
D
N
50
D
N
50
DMS DMS DMS
D
N
51
D
N
51
D
N
51
D
N
51
SEMPELL MODEL PSRV - PRESSURIZER SAFETY RELIEF VALVES
TYPE VS99 PILOT OPERATED
VALVE ASSEMBLY
At the reactor type EPR, three pressurizer safety relief valves type VS99 are mounted directly to
the side of the pressurizer. The inlet is arranged at an angle of 45°. Therefore the valve is installed
in a vertical position. A permanent water loop fills the main and pilot valves, so during blow down
purely sub-cooled water will be relieved first.
Two newly developed type Sierion pilot valves are assigned to one pressurizer safety relief valve.
The Sierion is a non-floating pilot valve which functions well with a wide variety of media such as
steam, water, two-phase flows and supercooled water.
THE EUROPEAN EPR SOLUTION
3 VS99 safety valve
3 x 2 Sierion pilot valve with stop valves for
the pilot and control line
3 x 1 DMS (doubled) bleed and feed valve
Pressurizer
Sierion
Pressurizer relief tank
Sierion
Sierion Sierion Sierion Sierion
Stop valves are attached between the main valve and the pilot valves for the impulse line and pilot
line. Only one pilot valves is active at a time, while the other is blocked by the stop valve.
The Sierion pilot valve is set to a defined set pressure. The response of the main valve under this
set pressure is ensured by activation through a double-solenoid valve type DMS. This is a further
variant of the so-called bleed and feed valve for pressure relief during emergency supply.