BCW Fill & Purge

BCW Fill & Purge

 ISOLATION OF CC PUMP
  • Remove from Stand by mode if it is in auto
  • 1.2 Stop CC pump if running
  • Isolate it Electrically
  • Close both discharge valve of CC pump if boiler is to be drained.
If Work is to be carried out in Motor Cooling Water Circuit
  • Isolate the inlet & outlet manual valve of LP cooler
  • Ensure the water flowmeter reading of LP coolercooler shows zero value.
If Work is to be carried out in Pump or in High Pressure line
  • Ensure the Unit is under Shutdown
  • Ensure that the Suction Manifold temp. is less than 100 deg C.
  • Close both discharge valve of all CC pumps.
  • Drain the Boiler
  • Open the pump casing vent of all CC pumps.
  • After water stops coming from all pump casing vent, then open the pump casing drain.
  • Ensure that the cavity is completely drained.
CC PUMP FILL PURGE
  • Ensure the following :
  1. Electrical Isolation of CC pump
  2. Both Discharge valve closed
  3. Boiler is in drained condition.
  • Ensure both manual valves (just before entering pump cavity ) for filling pump cavity are in close condition so that water does not enter pump cavity.
  • Ensure DM Make up pump is running.
  • Open the basket strainer drain
  • Ensure the supply valve from BFP discharge is close and open the supply valve from DM make up pump to basket strainer.
  • Flushing is to be carried out from basket strainer drain until clean water starts coming out.
  • Open the fine filter drain valve& close the basket strainer drain valve
  • Line Flushing to be carried out from fine filter drain valve until clean water starts coming out
  • Open the final drain valve just before entering BCW pump cavity& close the fine filter drain valve.
  • Line Flushing is to be carried out from drain valve just before entering pump cavity until clean water starts coming out & conductivity is less than 1 μs/cm.
  • Inform Chemistry to keep measuring conductivity of water on hourly basis until three consecutive readings of conductivity less than 1 μs/cm is achieved.
  • Adjust the flow rate of water coming out of drain to 5 LPM after chemistry clearance. (After three consecutive reading , conductivity less than 1 μs/cm )
  • Open the casing vent of all pumps & both the manual valves for cavity filling. Close the drain valve.
  • When water starts coming out from pump casing vent, measure the conductivity of water.
  • On Achieving three consecutive readings of conductivity less than 1 μs/cm, pump casing vent & cavity filling line manual valves are to be closed.
  • Close main supply valve from DM make up pump (For Purge & filling)
  • Inform EMD for Motor Meggering.Take Electrical Clearance before starting pump.
  • Open Both discharge valves of CC pump after drum filling.
  • Normalize cooling water isolation valves & note down the cooling water flow rate of LP & cooler.
  • BCW pump can be started & observe its cavity temperature

      Comments

      1. Firoj AhamedDecember 30, 2020 at 12:44 AM

        WHEN DO I NEED TO PURGE THE CAVITY OF CC PUMP OF AN UNIT COMMISSIONED 4 YEARS AGO?
        DO I NEED TO PURGE THE CAVITY IN A SHUTDOWN OF ONE WEEK FOR BOILER TUBE LEAKAGE
        ?

        ReplyDelete

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