STG-17 CV-1 FAILURE TO CLOSE DURING VALVE TEST.pptx

mscv

1. STG-17 CV-1 NOT CLOSING DURING VALVE TEST GROUP D POINTS

2. POSSIBLE CAUSES TEST SOLENOID NOT ACTIVATED OR COMMAND NOT GOING PROPERLY. SIGNAL TO TEST SOLENOID ISSUE FRD OR DRAIN PORTS IN ACTUATOR BLOCKED. STICKY SOLENOIDS HYDRAULIC FLUID CONTAMINATION (HIGH OXIDATION) VALVE STEM AND BUSHING CLEARANCE LESS DUE TO OXIDATION DEPOSIT

3. MAINTEANCE ACTIVITIES DONE SO FAR VALVE INSPECTION DONE DURING 2021 OUTAGE IMD CHECKED SOLENOID COMMAND AND POWER SUPPLY AND CHECKED ACTUATION OF SOLENOIDS PLACING PRESSURE GAUGES AT ACTUATOR PORTS. CONTROL VALVE ACTUATOR REPLACED 2 TIMES RECIRCULATION OF HYDRAULIC OIL THROUGH OIL WATER SEPERATOR HYDRAULIC OIL CHANGE.

4. RECOMMENDATIONS CONTROL VALVE STEM AND BUSHING INTERNAL INSPECTION AND HYDRAULIC OIL TESTING FOR OXIDATION-ASHWIN THERMOGRAPHY WHILE VALVE TEST BEING CARRIED OUT AND HYDRAULIC PUMP PRESSURE INCREASE AND CHECK-RAVI JOSHI.

5. VALVE INSPECTION REASONS