PROCEDURE FOR ESV 10012 TO REMAIN IN OPEN POSITION DURING WP1 SHUTDOWN
1. Check and confirm all the hydraulic supply and return lines of ESV 10012.
2. Fully close the two isolation valves (medium pressure and low pressure) at the hydraulic
return lines of ESV 10012.
RETURN LINE ISOLATION VALVE
RETURN LINE ISOLATION VALVE
3. Fully close the two isolation valves (medium pressure and low pressure) at the hydraulic
supply lines of ESV 10012.
SUPPLY LINE ISOLATION VALVE
4. Fully close NV1 and NV2 valve at LCP. ( Important: Note down number of turns to get
fully closed)
NV 1
NV 2
5. Note down the pressure reading of PG1 and PG2 at the LCP.
PG 1
VENT VALVE
ISOLATION VALVE
6. Check the vent valve of PG1 is fully closed.
7. Slowly open the vent cap.
8. Connect the hydraulic hand pump with the vent port of PG1.
HYDRAULIC HAND PUMP
9. Standby for shutdown.
10. After shutdown, observe the valve status locally (there may be small closing) and the
hydraulic pressure reading at LCP.
11. Apply hydraulic hand pump pressure 100 bar.
12. Slowly open the NV2 valve and then the vent valve of PG1.
VENT VALVE
NV 2
13. If needed, apply hydraulic pressure up to 100 bars (same as previous reading on PG1) so
that the ESV 10012 will retain its fully open position.
14. Check for any purging of hydraulic oil at the local ESV actuator and also check the
pressure reading at LCP.
15. When the valve status is OK, slowly close the vent valve of PG1 and NV2.
16. Remove the hydraulic hand pump and apply cap to the vent port of PG1.
Note: In the case of plant shutdown or ESV 10012 needs to be closed, fully open NV1, NV2
and the isolation valve at the medium pressure hydraulic return line.