"Boiler Feed Pump (BFP): Working, Applications, Advantages, and Limitations Explained"

A Boiler Feed Pump (BFP) is a critical component in thermal power plants. It supplies high-pressure water (feedwater) to the boiler, ensuring continuous steam generation.

⚙️ How a Boiler Feed Pump Works
Water Collection:
Feedwater is collected from the deaerator or feedwater tank.

Pressurization:
The pump increases water pressure using multiple impellers/stages in centrifugal types.

Discharge to Boiler:
Pressurized water is then supplied to the boiler drum or economizer section, depending on design.

🌀 Types of Boiler Feed Pumps
Centrifugal Pumps (most common):

Multistage for higher pressure.

Used in large thermal power stations.

Positive Displacement Pumps (less common):

For smaller or specific applications.

Precise flow control but less efficient for large volumes.

🛠️ Key Operations and Controls
Recirculation Line: Protects the pump from overheating at low flow.

Throttle Valve: Regulates flow based on boiler demand.

Control System: Often automated via DCS/PLC for variable load conditions.

Sealing & Cooling Systems: Prevent leakage and maintain pump health.

⚠️ Common BFP Issues
Cavitation due to low NPSH (Net Positive Suction Head).

Seal or bearing failure.

Overheating from improper flow or recirculation.
https://www.infopitaara.in/

1. Boiler Feed Pump
Basics
&
Operation
Infopitaara
Prepared by-

5. BFP(Stage-1, 200 MW , KSTPS)
Specification
No-3 nos(2X 50%)
Type-Motor driven
Motor-6.6 KV
Motor speed -1485 rpm, 3500 Kw
Booster p/p-single stage centrifugal
Main p/p-8 stage centrifugal p/p

6. Deliver Your Presentation
Broadcast and compress for seamless delivery
MOTOR
To D/A
Suction v/v
Strainer
R/C v/v
NRV
Discharge v/v
Transfer line
Booster
Pump
Main
Pump
Gear box
&
Hydraulic
coupling
D/A
To BFP Discharge
Header
Transfer line vent
Booster p/p casing vent
Suction Line
drain
R/C line vent
R/C line drain
Main p/p
casing drain
Disc. Line
drain
BFP Line Diagram
B
P
c
a
s
in
g
d
r
a
in
Booster Pump (Specifications)
Single Stage Centrifugal Type
Manufacturer- Wier P/P’s Ltd.
Speed- 1485 rpm.
Motor (Specifications)
6.6 KV, Induction Motor
Power- 3.5 MW, Current- 360 Amp.
Speed- 1485 rpm.
Lub oil p/p
Working oil p/p
Lube oil tank
Hydraulic coupling
Speed output- 4750 rpm
Slip % - 3.9
1 2
3
45
6
7
8
9
10
Scoop tube
Step-up Gear Unit
Gear ratio- 1:3.3
Gear box & Hydraulic Coupling
•BFP Main pump (Specifications)
•8- Stage, Cartridge Type, Centrifugal
•Weir Co. made - FK8D30.
•Speed- 4750 rpm.

7. Main pump
The weir type FK8D30 pressure stage pump
is an eight stage horizontal centrifugal
pump of the barrel casing design.
The pump internals are designed as a
cartridge, which can be easily removed for
maintenance without disturbing the suction
and discharge pipe work, or the alignment
of the pump and the turbo coupling.

8. BFP Main pump Drawing

9. BFP BARREL & CARTRIDGE

10. BFP CARTRIDGE
BFP CARTRIDGE ASSEMBLY COMPRISES OF THE FOLLOWING
SALIENT PARTS :
 SHAFT
 IMPELLERS
 DIFFUSERS
 RING SECTIONS
 SUCTION GUIDE
DISCHARGE COVER
BEARING HOUSINGS
 BEARING BRACKETS
 JOURNAL BEARINGS
 THRUST BEARING
MECHANICAL SEALS

IN OTHER WORDS BFP CARTRIDGE IS A COMPLETE PUMP EXCEPTING
BARREL (PUMP CASING).

11. BFP CARTRIDGE
ADVANTAGES :
IN CASE OF A BREAK DOWN OF RUNNING PUMP, SPARE
CARTRIDGE CAN REPLACE IT TOTALLY.
 DOWN TIME FOR CHANGE OVER WILL BE MINIMUM (ONE OR
TWO SHIFTS)
 SPARE CARTRIDGE RESTORES THE ORIGINAL EFFICIENCY OF
THE PUMP
 SEMI SKILLED TECHNICIANS CAN CARRY OUT THE
REPLACEMENT.

12. It houses the hydraulic components of Pumps.
It prevents the leakage and guides the liquid in a
proper direction.
 It is closed by Suction Guide at it’s suction side and
Discharge
Cover at it’s discharge side.
PUMP CASING

13. It rotates the mass of fluid with the peripheral speed
of its vane tips, thereby determining the head
developed or the Pump working pressure.
IMPELLER

14. It converts Kinetic energy of the fluid into Pressure Energy.
INTER-STAGE DIFFUSER END-DIFFUSER
DIFFUSER

15.  It consists of Ring Sections located one to another.
 Each Ring Section houses one Impeller and one Diffuser.
 Ring Sections along with Diffusers form the passage of liquid from
the Impeller outlet of one stage to the Impeller inlet of the next
stage.
RING-SECTION ASSEMBLY

16. It consists of Shaft, Impellers, Balance Drum, Thrust Collar,
rotating parts of Mechanical Seals and the Pump Half Coupling.
ROTATING ASSEMBLY

19.  They locate the rotor axially & take residual axial thrust.
 They are fitted in the NDE Bearing Housing.
They have 8 white metal lined tilting pads held in a split Carrier
Ring positioned on each side of the Thrust Collar.
Carrier Rings are prevented from rotating with the Shaft by dowel
pins in each ring which engage in slots in the Bearing Housing top
half.
THRUST BEARING

25. Main pump & Booster pump Sealing
The pump shaft is sealed at the drive end and non-
drive end by Crane mechanical seals, each seal
being flushed by water in a closed circuit and the
water is circulated by the action of the seal
retaining ring.
The flushing water is cooled by passing through
seal coolers, (two coolers per seal, one working and
one standby), and each seal cooler being circulated
with clarified cooling water.
The rotating assembly is supported by plain white
metal lined journal bearings and axially located by
a Glacier double tilting pad thrust bearing.

26. Sealing system
Mechanical seals are used in MP & BP
Clarified water used for seal cooling
Mechanical seal cooling arrangement in main p/pMechanical seal cooling arrangement in main p/p
Mechanical seal
cooler
DM water running in closed ckt
Hot DM
cooling water
Cold DM cooling water
Clarified water used
for cooling of DM water
Clarified o/l

27. MECHANICAL SEAL
P/p shaftO ringCarbon steel(static)
Tungsten
carbide
(rotating)
P/p casing

28. It consists of two highly polished surfaces, one surface connected to the Shaft and the
other to the stationary part of the Pump.
Both the surfaces are of dissimilar materials held in continuous contact by a spring.
These wearing surfaces are perpendicular to the axis of Shaft.
A thin film of working fluid between these faces provides cooling & lubrication.
MECHANICAL SEAL

30. Hydraulic Thrust balancing Drum.
Due to differential pressures acting on the impeller the
rotating assembly is subjected to axial thrusts. The balance
drum located at the non-drive end is designed to keep these
forces neutralised and only the residual thrust remains, which
is taken up by thrust bearing.
The main components of hydraulic balancing arrangement are
the balance chamber machined in discharge cover, the balance
drum secured to the shaft and balance drum bush fitted in the
bore of discharge cover.
The thrust caused by the suction pressure acting on the area
inside the wear ring on inlet side of each impeller is overcome
by much greater thrust caused by the discharge pressure
acting on the equivalent area on the outlet side of each
impeller.
The resultant thrust is therefore towards drive end of pump.
Thrust force varies with load on the pump but hydraulic
balance arrangement will reduce its effect enabling residual
thrust to be taken by fitting pads of thrust bearing.

31. Thrust balancing
Balancing disc is provided in main p/p
Balance leak off pr-16 ksc.

33. BP ASSEMBLY
BOOSTER PUMP

35. Booster Pump Drawing

36. BFP Lub oil system
Main p/p -- DE side-journal brg
– NDE side-journal & trust bearing
Booster p/p-p/p- DE side-journal brg
– NDE side-journal & trust bearing
– Hydraulic coupling-10 bearings(4 thrust
bearings, rest-journal bearings)
Lub oil system-2 source
1)MOP-shaft driven
2)AOP-motor driven

37. Lub oil scheme
2 no lub oil cooler
AOP
AOP motor
MOP(connected to gear box)
Lub oil filter
Oil header
Booster p/p bearings
NRV
Motor bearings
Main p/p brg
Return from bearing
Oil tank
Raw water from
ARCW discharge

38. When BFP is in S/B condition motor driven AOP is
in service. Pr is around 3 ksc.
When we give start command to BFP motor driven
cut out in auto at 2.3 ksc pr(gear driven MOP will
supply lub. oil to bearings

39. Bearings
Journal bearings
White metal liner(babbit metal)
Thickness-0.5 mm
shaft
Lub oil
Journal bearing

40. LUB OIL TANK
Regulation
control
Working oil
make up
drain
Hydraulic coupling
Hot working oil
Cold working oil
WC p/p
Cooling water
From ARCW P/P
Working oil scheme
Working oil cooler
(2 in numbers)
CW in
CW out

41. • Hydraulic Coupling of BFP

43. SCOOP TUBE ASSEMBELY

44. SCOOP TUBE WORKING MECHANISM

45. Motor cooler
BFP Motor cooling Arrangement
2 cooling fans are provided at the both ends of motor
Cooling air fans sucks cold air which cools motor stator
/rotor
Hot air is cooled by water in the cooler(2 no of cooler
provided)
Cooling water coming from Aux. Raw cooling water
p/p(ARCW p/p)discharge header
Motor cooler
Cold air
Hot air
Motor stator
Motor rotor
To WC
cooler
Cooling water
BCW
v/v

46. WHY Recirculation ?
For minimum FW flow.
To avoid churning
BFP discharge header
To D/A
A
B
180 kg
0 kg
180 kg
100kg
181kg

47. BFP parameter
UCB parameter Normal value
BFP current 290-300amp
BFP flow340 ton/hr
BFP(MP) discharge pr 180 kg
D/A pr6.5 ksc
BFP suction temp167 degree
BFP suction strainer DP0.07
Drum level +50 mm
Lub oil pr3 ksc
Lub oil cooler in servicenormally one
Lub oil temp cooler I/l/O/L 60/40 degree
Local parameter

48. Local parameter Normal value
Working oil pr 1.4 ksc
Working oil cooler in service normally one
Working oil temp cooler I/l/O/L 120/75 degree
Hydraulic coupling max bearing temp 65 degree
Motor air temp 50 degree
Clarified water pr 3.5 ksc
Balance leak off pr 16 ksc
BP suction pr 8 kg
MP suction pr 16 ksc

49. BFP Start Permissives
1. Deareator level normal > 800 mm.
2. Lube oil pressure adequate > 1.5 ksc.
3. Main pump/Motor bearing temp. normal < 75 deg. C.
4. Suction valve full open.
5. Suction pressure of booster pump adequate > 2.0 Ksc.
6. Emergency push button released.
7. Discharge valve closed or any BFP running & header
pressure normal > 90 Ksc.
8. Recirculation valve open.

50. BFP Protections
Sr.
No.
Parameters
Alarm
Value
Trip Value /
Remarks
1Motor [DE/NDE] bearing temperature 75ºC 85ºC
2Main pump [DE/NDE] bearing temperature 75ºC 85ºC
3Lube oil pressure low < 1.2 Ksc
< 0.8 Ksc
(Time delay – 5 sec)
4Working oil temp Hi-Hi 90ºC > 130ºC
5
BFP running & Main pump suction pressure
low
< 12 Ksc < 8 Ksc
6BFP Flow Hi-Hi 450 T/hr
450 T/hr
(Time delay – 55 sec)
7Deaerator level low-low
550 mm 400 mm
8
Emergency Push Button Pressed

51. BFP Protections
1. Motor [DE/NDE] bearing temp. (Alarm: 75ºC, Trip: 85ºC)
In Unit-1 & 2 – Temperatures provided in Omniguard.
In Unit- 3 - Temperatures provided in DAS, Group-86 (2
RTD’s, Alarm through any one, Trip- 2/2 logic)
2. Main pump[DE/NDE] bearing temp. (Alarm:75ºC, Trip: 85ºC)
In Unit-1 & 2 – Temperatures provided in Omniguard.
In Unit- 3 - Temperatures provided in DAS, Group-86 (2
RTD’s, Alarm through any one, Trip- 2/2 logic)
3. Lube oil pressure low (Alarm:<1.2 Ksc,Trip:<0.8ksc,Td=5 sec)
AOP Cut in at – Lube oil press < 1.7 Ksc.
AOP Cut out at – Lube oil press > 2.9 Ksc.

52. BFP Protections
4. Working oil temp Hi-Hi. (Alarm:90ºC, Trip: >130ºC)
Alarm & Tripping through- Temp guage cum switch (in local)
5. BFP running & Main pump suction pressure low (< 8 KSC).
Through one pressure switch.
6. BFP Flow Hi-Hi. (Alarm: 450 T/hr,Trip>450 T/hr, Td=55 sec).
In Unit-1 & 3 – BFP flow hi-hi is through 2 Tx’s (2/2 logic)
In Unit-2 – BFP flow hi-hi is through one switch & one Tx
combination (2/2 logic).
7. Deaerator level low-low (Alarm: 550mm, Trip: 400mm)
8. Emergency push button.

53. BFP, Local C&I Connections

54. BFP Isolations
1. Ensure that pump is in stopped condition.
2. Get the main motor breaker isolated ( Electrical isolation).
3. Close discharge valve and isolate its electrical supply .
4. Close the suction valve .Ensure there is no rise in suction
press.
5. Open suction strainer, booster pump casing, discharge line
and main pump casing drain valves.
6. Open the transfer line vent, booster pump vent.
7. Close the manual recirculation valve at deaerator level.
8. Stop AOP .Isolate its electrical supply. (bearing temp.< 45ºC)

55. BFP Normalisations
1. Physically check that work is complete and all men and
materials are removed from site.
2. Get the electrical supply of AOP normalised.
3. Ensure that one lube oil cooler and one working oil cooler
are charged from oil and water side.
4. Check oil level ( It should be more than 50 %)
Start AOP, observe lube oil pressure (It should be more than
2.5 ksc) and oil filter DP (It should be less than 0.5 ksc).Check
return oil flow in all bearings.
5. Open motor cooling inlet/outlet valves .

56. BFP Normalisations
6. Ensure booster pump,transfer line & recirculation line
vents open , Close all drains. (To avoid pressurisation of
pump).
7. Charge clarified water to mech seal coolers and jacket
cooling. Ensure clarified water Pressure is more than 3 ksc .
8. Open manual recirculation valve at deaerator and ensure
recirculation control valve is open. Also ensure air supply to
recirculation control valve.
9. Crack open suction and observe the discharge through the
vents. Close the vent valves after venting is over.

57. 10. Open suction valve fully and ensure the suction pressure
is adequate.
11. Get the discharge valve and its integral bypass valves
supply, BCW valve supply normalized .
12. Open its discharge valve from UCB, Ensure there is no
reverse rotation of the pump.
13. Get the main motor electrically normalised.
BFP Normalisations

58. BFP Lube Oil Filter Changeover
Two lube oil filters provided in BFP Main pump.

1. No charging line provided.
2. No venting provided in both lube oil filters.
Lube oil filter chocked alarm provided in alarm fascia.
(Lube oil filter chocked at DP > 0.5 Ksc)
BFP tripping on lube oil pressure low-low at 0.8 Ksc, Time
delay- 5 seconds.

59. Lube oil
Filter-A
in-service
Hydraulic Coupling
Pointer, T shape bottom
For Lube oil filter change over moves the handle in this direction
Yellow Mark on Handle & Nut

60. Lube oil
Filter-B
in-service
Hydraulic Coupling
Pointer, T shape bottom
For Lube oil filter change over moves the handle in this direction
Yellow Mark on Handle & Nut

62. BFP Lube Oil Filter Change Over.
During Changeover :-
Place the handle over nut by matching the Yellow Mark.(Half
Yellow mark on Nut & Half Yellow mark on handle)
Slowly rotates the change over handle (180 degree) so that the
pointer (bottom part of T) provided in the nut always moves
towards the Hydraulic coupling side.
When pointer moves towards Hydraulic coupling- both filters
remain in service in pointer mid position.
When pointer moves opposite to Hydraulic coupling- both filters
became out of service in pointer mid position.
The pointer (bottom part of T) shows the Lube oil filter in-service.
Observe the rise in DP of filter to be taken in service.

63. Drum Level Control (Stage-1, 200 MW, KSTPS)
Low range
FRS
CV
BFP-A
scoop
BFP-B
scoop
BFP-C
scoop
BFP
master
BFP
DP control
BFP
scoop
control
Hi range
FRS
CV
Three
Element
controller
Single element
controller
Hi range
FRS
CV
Drum level

64. PV 79
SV 70
MV 44.7
569 TPH 562.3 TPH
FRS-
LOW
0.0 %
57 MMFEED FLOW STEAM FLOW DRUM LEVEL
PV 0.5
SV5.5
MV 55
PV 57
SV 23
MV 0.0
PV 79
SV 68
MV 100
AUT MAN
AUT MAN
1-ELEMENT TO 3-ELEMENT
SELECTION
SELECTION
FRS-A
100 %
FB= 99.9
FRS-B
100 %
FB= 101.1
1- ELEMENT FRS CONTROL 3-ELEMENT FRS CONTROL 3-ELEMENT SCOOP CONTROL DP SCOOP CONTROL
BFP-A ON
SUC FLOW 273 T/Hr
BFP-B ON
SUC FLOW 307 T/Hr
BFP-C OFF
SUC FLOW 0 T/Hr

CAS CAS CAS
CAS
AUT AUTAUT
44.7 %
DP 1 : SW=1
DP 2 : SW=2
MS : SW=1
BLI : SW=2
MS SELECTOR
PR 1 : SW=1
PR 2 : SW=2
FS PR SELECTOR
DP SELECTOR

65. Drum Level Control (Stage-1, 200MW KSTPS)
1. 3-Elements – Drum Level, Steam flow & feed water flow.
Drum Level - Measured through 2 Tx’s (Left & Right,
one Tx in selection).
Steam Flow – Measured through flow nozzle &
calculated through 1
st
stage pressure.
(one in selection)
Feed Water Flow - Measured through 2 Tx’s (one Tx in
selection).
2. 1-Element Controller – FRS Low Range Control Valve.
Maintain only drum level {auto & manual} .
For BLI < 30% operation.

66. 3. 3-Element Controller – FRS High Range Control Valves (FRS-
A & FRS-B).
Maintain only drum level {auto & manual} .
For BLI > 30% operation.
Can be loop with DP and Scoop controllers.
Independent operation not required BFP Master in
auto.
4. DP Controller – Maintain DP across FRS high range CV’s.
DP maintained by BFP’s scoop & FRS CV’s maintains
drum level.
Requires FRS high range CV’s in auto & BFP master in
auto.
For BLI > 30% operation.
Gives command to BFP’s scoop through BFP master.
Feedback from 2- DP Tx’s across FRS high range CV’s.
Drum Level Control (Stage-1, 200MW KSTPS)

67. Drum Level Control (Stage-1)
5. Scoop Controller – Maintain drum level directly through
BFP scoop.
Requires FRS high range CV’s 100% open in forced
manual & BFP master in auto.
For BLI > 70 % operation.
Gives command to BFP’s scoop through BFP master.
6. BFP Master– Gives command to BFP scoop’s and requires 2
BFP’s out of 3 in auto for BFP Master in auto.

Drum Level Control (Stage-1, 200MW KSTPS)

68. 1. 1- Element to 3-Element Changeover
At BLI > 30 %, 1-Element to 3-Element auto changeover,
but,
At BLI < 30 %, 3-Element to 1-Element auto changeover
doesn’t occur.
During 1-Element to 3-Element auto changeover, 3-Element
controller will be in manual, until we put in auto.
For smooth changeover put MV of 3-Element controller >
30%, before changeover.
Drum Level Control (Stage-1, 200MW KSTPS)

69. 2. Scoop to DP Controller Changeover
At BLI < 70 %, Scoop to DP auto changeover, but at BLI >
70 %, DP to Scoop auto changeover doesn’t occur.
Immediate Command to FRS high range controller to
25%, (MV becomes 25), FRS high range CV’s throttles
with a ramp rate of 50% per minute in MANUAL.

FRS high range CV’s closes till DP reaches the +/- 1
deviation band of Set value of DP Controller and
then ,FRS high range & DP controllers immediately go to
AUTO.
For smooth change over, put DP set point (SV) of DP
controller 5 – 6 Ksc.

Drum Level Control (Stage-1, 200MW KSTPS)

70. Drum Level Control Logics (Stage-1)
3. DP to Scoop Controller Changeover

At BLI > 70 %, we can put Drum level in Scoop
Controller.
Immediate Command to FRS high range controller to
100%, (MV becomes 100) and 3-Element controller in
Forced Manual, FRS high range CV’s opens with a ramp
rate of 10% per minute.

If FRS high range CV’s does not open 100% within 300
seconds, then a second command extends for 100 %
opening of CV’s with a ramp rate of 100% per minute.

71. 4. Controllers logic in Drum Level Mimic
Controller in Manual – We can only change the value of
MV.
(SV & PV remains inoperative)
Controller in Auto- We can only change the SV. (PV
comes from 3 elements & MV changes according to
difference in SV & PV).

Controller in Forced Manual – We can’t change the MV.
Slave controllers can be put in Auto, Manual and
Cascaded.
In cascaded mode (CAS) slave controller is taking
command from master controller (It does not work
independently).
PV- Process value, SV – Set value, MV – Manipulated
value
Drum Level Control (Stage-1, 200MW KSTPS)

72. Sequence of Activities from light up to Full Load.
Checks (Before taking first BFP in service):-
FRS low range CV, FRS high range control v/v’s in Cascaded
mode (CAS) & full closed condition.
Open the FRS low range & high range motorised isolating
v/v’s (upstream and downstream).
Activities:-
1. Start the first BFP & take FRS low range (1-Element)
controller in service (auto or manual, preferably in auto).
Control the drum level through 1-Element up to BLI – 30%.
Drum Level Control (Stage-1, 200MW KSTPS)

73. 2. At BLI > 30% FRS low range to high range autochange over
done, but FRS High range (3-Element) controller will be in
manual, so before changeover at BLI –30 %, set the MV of 3-
Element controller between 30 – 40 %. After changeover, put
3-Element controller in Auto.
FRS high range controller work independently and maintain
the drum. (After Change over 1-Element controller will also
remain in auto)
Drum Level Control (Stage-1, 200MW KSTPS)

74. 3. For putting Drum level in DP control (only at BLI >30%),
First make sure 3-Element controller in Auto. After that put 2
BFP’s in Auto (from UCB desk) so that BFP master in Auto &
put the SV of DP controller 5 to 6 KSC, then put the DP
controller in Auto.
Now DP controller maintain the DP across FRS high range
CV’s by operating the BFP’s scoop through BFP Master & FRS
high range CV’s maintain the drum level.
Range of operation of DP controller is BLI – 30% to 100%.
Drum Level Control (Stage-1, 200MW KSTPS)

75. 4. At BLI > 70%, we can put drum level in Scoop control, for
that only click on the selection switch.
FRS high range CV’s opened-100% in Forced Manual and
Scoop controller goes to Auto. Now, BFP master control the
drum level by operating the running BFP’s scoop in Auto.
Drum Level Control (Stage-1, 200MW KSTPS)

76. Note :-
1. If drum level is in Scoop control and we take BFP master in
manual (by taking 2 BFP’s in manual), Scoop controller goes
to manual and FRS high range control v/v’s remains full open
in Manual (3-Element controller will remain in Manual).
2. If drum level is in DP control and we take BFP master in
manual (by taking 2 BFP’s in manual), DP controller goes to
manual but 3-Element controller remains in auto (FRS high
range control v/v’s opened & closed in auto to maintain the
drum level only.)
Drum Level Control (Stage-1, 200MW KSTPS)

77. PV 79
SV 70
MV 44.7
569 TPH 562.3 TPH
FRS-
LOW
0.0 %
57 MMFEED FLOW STEAM FLOW DRUM LEVEL
PV 0.5
SV 5.5
MV 55
PV 57
SV 23
MV 0.0
PV 79
SV 68
MV 100
AUT MAN
AUT MAN
1-ELEMENT TO 3-ELEMENT
SELECTION
SELECTION
FRS-A
100 %
FB= 99.9
FRS-B
100 %
FB= 101.1
1- ELEMENT FRS CONTROL 3-ELEMENT FRS CONTROL 3-ELEMENT SCOOP CONTROL DP SCOOP CONTROL
BFP-A ON
SUC FLOW 273 T/Hr
BFP-B ON
SUC FLOW 307 T/Hr
BFP-C OFF
SUC FLOW 0 T/Hr

CAS CAS CAS
CAS
AUT AUTAUT
44.7 %
DP 1 : SW=1
DP 2 : SW=2
MS : SW=1
BLI : SW=2
MS SELECTOR
PR 1 : SW=1
PR 2 : SW=2
FS PR SELECTOR
DP SELECTOR
Manual Mode Auto Mode Cascaded Mode
PV
DP/3 ELEMENT
SELECTOR
0
DP CNTR

78. PV 79
SV 30
MV 35
569 TPH 562.3 TPH
FRS-
LOW
0.0 %
57 MMFEED FLOW STEAM FLOW DRUM LEVEL
PV5.5
SV5.5
MV 58
PV 57
SV 23
MV 0.0
PV 79
SV 68
MV 60
AUT AUT
MAN AUT
1-ELEMENT TO 3-ELEMENT
SELECTION
SELECTION
FRS-A
60 %
FB= 60
FRS-B
60 %
FB= 62
1- ELEMENT FRS CONTROL 3-ELEMENT FRS CONTROL 3-ELEMENT SCOOP CONTROL DP SCOOP CONTROL
BFP-A ON
SUC FLOW 273 T/Hr
BFP-B ON
SUC FLOW 307 T/Hr
BFP-C OFF
SUC FLOW 0 T/Hr

CAS CAS CAS
CAS
AUT AUTAUT
58%
DP 1 : SW=1
DP 2 : SW=2
MS : SW=1
BLI : SW=2
MS SELECTOR
PR 1 : SW=1
PR 2 : SW=2
FS PR SELECTOR
DP SELECTOR

79. BFP- Emergency Handling (Stage-1, 200 MW)
Condition:-
Unit running at full load (200 MW), with two BFP’s in service
and one BFP under permit. Suddenly one BFP Trips.
Consequences:-
1. Drum level starts decreasing rapidly.
2. Only running BFP flow goes High, Then Hi-Hi to maintain the
drum level. (and chances are BFP trip on Flow Hi-Hi).
Boiler May Trip on:-
1. Drum Level Lo-Lo (-250 mm, Time delay- 10 sec), OR
2. All BFP’s Trip.

80. ACTIONS TO BE TAKEN
BFP- Emergency Handling (Stage-1, 200 MW)

81. 1. If M/C is in CMC, take it out into Turbine pressure Control
Mode.
2. Continuous Three Mills to be kept in service, rest other
mills hand tripped (Pulveriser made OFF).
3. Running BFP should be taken into Manual & try to
maximize the flow (above 400 T/Hr), keep recirculation in
auto. (BFP flow High & Hi-Hi alarms provided in different
alarm fascia).
4. Ensuring Flame Stability through Fire Ball Scanners, Oil
Guns may be taken in service.
BFP – Emergency Handling (Do’s)

82. BFP – Emergency Handling (Do’s)
5. Boiler firing is to be reduced so that the Steam Flow should
be less than Feed Water Flow, to improve Drum level,
consequently load reduces.
6. If further required another Mill also can be tripped by
taking Oil gun in the running Mill combination elevation.
7. Try to restore the tripped BFP at the earliest (like in case of
human error) and take it into service to maintain the drum
level.

83. ACTIONS NOT TO BE
TAKEN

BFP- Emergency Handling (Stage-1, 200 MW)

84. BFP – Emergency Handling (Don'ts)
1. Do not operate the Load Limiter or Load reference, if M/C
is in pressure controller. (Fast unloading of turbine will
increase the drum pressure which will lead into more BFP
discharge pressure and BFP flow decreases).
2. Do not operate the HP Bypass. (Extra BFP flow is added as
a HP Bypass spray due to opening of BD Valves).
3. Do not press the EPB of any BFP in which permit is to
be given if its electrical isolation is already done . (To
avoid the chances of Human Error)

85. DO NOT PRESS THE EPB OF BFP

86. Recommendations
1. BFP suction strainer DP to be provided in Drum Level
Mimic.
2. Working oil temperature of BFP to be provided in UCB.
3. BFP Main pump suction pressure value to be provided in
UCB.
4. At BLI<30%, 3-Element to 1-Element changeover should
occur in Auto.
5. At BLI>30%, High Range Controller should come in Auto.