Reasons of Failure:
Ø Failure
of control supply of compressor
Ø Loss
of Cooling Water (SG ECW Pump Trip)
Ø Massive
leakage in IA supply Header
Ø One
Unit Under Overhaul. Unit Aux Board/ Station Aux board got Tripped of that Unit
Problems/Actions:
Ø No
Oil guns can be taken in service: Oil/steam Valves remain Inoperative. Igniter
Will not advance
Ø If
Unit on only Oil guns: Boiler will Trip. (HOTV/LOTV will close)
Ø Stay
Put :
·
HAG/HAD/CAG/CAD. No mill
can be taken in service.
·
SADC,
·
Burner tilt (if leakage
the it will go Up),
·
SH/RH spray control
valves( close due to leakage),
·
Seal Air Fan discharge
/damper,
·
Scanner air fain
Discharge Damper
·
D/A Level controllers (
close if Air Leakage)- Maintain Level through Motorized Bypass Valve
·
TDBFP Seal steam
supply/dump –Maintain through Bypass motorized valve
·
FRS 30%(FDV-14) if Open
(Close on leakage)- control Drum through Scoop, TDBFP Scoop may Increase or
Decrease, Open High Range FRs 100 % line
Ø Close:
·
SH/RH spray Block .Open
SH/RH block v/v manually if Temperature is running high
·
Vacuum Pump inlet v/v
will start closing(vacuum will fall)
·
HP/LP Heaters normal
Drip
Ø Open:
·
Running BFPs
Recirculation Valve ( Start MDBFP or Reduce Load)
·
CEP recirculation –
start Standby CEP to maintain H/W, D/A OR Reduce Load
·
GSC Recirculation will
Open: Reduce condensate to D/A- Close its Manual valve
·
Normal Make-Up –maintain
level through Bypass valve OR through Manual valve
·
HP/LP Heaters emergency
Drip
·
Deaerator Overflow valve
Ø Open
PAC-IAC Interconnection.
Ø Isolate
Plant Air Supply to boiler of both Units.
Ø Inform
other stage to run Additional IAC and Open Interconnection b/w stages
Ø C&I should periodically check the healthiness of
the lock out relay for maintaining stay put condition and maintain records of such
checking.
Important Points at IAC Failure:
Ø Steam
Temperature
Ø Condenser
Vacuum
Ø Drum
Level
Ø Deaerator
& Hotwell Level
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