Condenser : One Pass Isolation

1 Ensure the availability of both condenser de-watering pumps.
2 Decrease the load to 300 – 350 MW
3 Ensure that both CW interconnection valve are opened
4 Start Stand by Vacuum pump

5 If 4 no. CW pumps are running , stop 1 CW pump
6 Close the inlet and outlet MOV of the condenser pass to be isolated.
7 Isolate the isolating manual valve of signal oil of both control and stop valve of LP Bypass of the pass to be isolated.
8 Close the vacuum pump inletmanual valve of the CW pass to be isolated.(Location near LP Bypass CV)
9 Open both the front and rear vents of the condenser pass to be isolated
10 Start the condenser dewatering pumps.
11 Observe the water flow from the vents. If the flow from vent line is still high ,CW inlet & outlet MOV is to be manually tightened with the help of TMD. Check CW inlet pressure
gauge at local.
12 Open CW waterbox drain valve in controlled manner so that sub-zero condenser pit level should not rise.
13 When the water from the vents stops coming , CW inlet duct drain valve (After CW inlet MOV ) to be opened in consultation with TMD if required.
14 PTW to be issued after complete draining of water box.