Generally Pumps classification done on the basis of its mechanical configuration and their working principle.

PUMPS USED IN THERMAL
POWER PLANT

PROGRAMME
SESSION TOPIC
FORENOON SELECTION & DESIGN
ASPECTS
AFTERNOON CONSTRUCTIONAL
FEATURES & MATERIALS
OF CONSTRUCTION

Pump is a device –
which converts
mechanical energy
into
pressure energy
due to which the fluid moves
from one point to another.

(A) CENTRIFUGAL PUMPS :
Energy is generated through the
centrifugal force of the vortex.
(B) POSITIVE DISPLACEMENT PUMPS :
Energy is generated by the direct
displacement of the fluid.
TYPES OF PUMPS

INPUTS REQUIRED
• APPLICATION : SYSTEM, DUTY & OPERATION
• FLOW RATE, TOTAL HEAD, TEMPERATURE
• TYPE OF FLUID
• SUCTION HEAD AVAILABLE
• FREQUENCY OF OPERATION
• SUPPLY VOLTAGE
Essential information User to specify :

SELECTION OF PUMP
Based on the inputs received from the user,
A suitable pump model is chosen based on following aspects :
Hydraulic Selection
Mechanical Construction features
Materials of construction

CHARACTERISTIC CURVE OF A PUMP
1000
1200
1400
1600
1800
HEAD
(mlc)
0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450
SUCTION FLOW (cub. m. / hr.)
0
10
20
30
40
50
60
70
80
90
EFFICIENCY
(%)
0
5
10
15
20
NPSHR
(mlc)
500
1000
1500
2000
POWER
(kW)
3% 
50 Hz
52.5 Hz
47.5 Hz

• PUMP CHARACTERISTICS :
- It is the relationship between Capacity, Head, Power and
Efficiency.
- The graphs, showing the inter-relationship between
Capacity, Head, Power and Efficiency, are called
Pump Characteristic Curves.
➢ Capacity :
- It is the quantity of fluid flowing through the Pump for a
given time of period.
- It is expressed in m3/hr.
- It is measured by weight method, volumetric method,
orifice plate or by weirs.
➢ Head :
- It is the measure of energy to move the fluid from one
point to another.
- It is expressed in metres of liquid column.

➢ Power :
- The horse power produced by the liquid is called as
Water Horse Power (WHP) or Liquid Horse Power
which is expressed as
WHP = ( Q H) / 75
where Q = m3/sec , H = mlc &  = kg/m3
- The power required to drive the pump is called as
Brake Horse Power (BHP) which is expressed as
BHP = ( Q H) / 75 
where  is the efficiency of Pump.
➢ Efficiency :
- It is the measure of the Pump performance.
- It is the ratio of WHP to BHP.

• NET POSITIVE SUCTION HEAD (NPSH) :
➢ Available (NPSHA) :
- NPSHA is the total Suction Head of liquid (absolute),
determined at the first stage Impeller datum,
less the absolute vapour pressure of the liquid at a
specified Capacity.
NPSHA = hsa - hvp
where hsa = Total Suction Head (abs) = hatm + hs
hatm = Suction Pressure
hs = Static Water level at reference datum
hvp = Absolute Vapour Pressure of liquid at
pumping Temperature
- NPSH is the parameter used to evaluate the suction
conditions of the system.

➢ Required (NPSHR) :
- It is a parameter of the selected Pump.
- It is the amount of Suction Head, over Vapour
Pressure, required to prevent more than 3% loss in
total Head from the first stage of the Pump at a
specified Capacity.
- It is an important parameter in the pumping system to
ensure that the NPSHA (which is determined by the
system) is at least equal to the NPSHR by the Pump
(which is a function of Impeller design & Pump Speed).
- It is required to ensure adequate margin between
NPSHA & NPSHR.
- It is therefore essential that the Pump manufacturer is
given adequate information on NPSHA, operating
Flow range, transient conditions, etc., so that the
best Pump selection can be put forward.

COMPARISION BETWEEN NPSHA & NPSHR :
 
NPSH
AVAILABLE
REQUIRED

• SYSTEM HEAD :
- It is the total head of a system against which a pump
must operate.
- For a given capacity, it is expressed as
System Head = Total Static Head from supplying level
to discharge level + Discharge Pressure - Suction
Pressure - Friction losses - entrance and exit losses
 




      
   
             
         

• OPERATING CONDITIONS :
  




         
                   
                

• PARALLEL OPERATION :
 




PUMP A
PUMP B
SYSTEM HEAD
COMBINED

• SPECIFIC SPEED :
- It is the speed of a geometrically similar Pump which
delivers one unit of Capacity against one unit of total
Head.
- It is generally used for comparison between various
types of Centrifugal Pumps.
- It is expressed as
NS = ( N Q ) / H3/4
where N is the Speed of the Pump, rpm.
- It determines the type of Impeller.
- It’s value varies from 30 to 1000 for Centrifugal Pumps.
➢ Radial Flow Impeller = 30-290
➢ Mixed Flow Impeller = 290-440
➢ Axial Flow Impeller = 440-1000

• AFFINITY LAWS :
- All Centrifugal Pumps follow the Affinity Laws which are
given below :
Q  N Q  D
H  N2 and H  D2
P  N3 P  D3
where N is the Speed of the Pump (rpm) &
D is the Diameter of the Impeller

Optimisation of sizing & design margins
➢ Design margins are provided on equipment / systems
to cater for ageing, wear & tear, uncertainties etc
➢ Conservative designs with large margins ( e.g. on flow
and head of pumps) and specifying suitability for
abnormal operating conditions result in lower
efficiency and higher auxiliary power consumption
➢ Proper standby philosophy based on efficiency of
operation, availability & reliability, like
1x100% Working + 1x100% Standby or
1x100% Working + 1x30% Startup or
2x50% Working + 1x50% Standby etc.

OPTIMUM DESIGN MARGINS
COMPARISON OF 500 MW CEP PARAMETERS
Project-A Project-B
Capacity (M3
/Hr) 835 800
Head (MLC) 350 275
Power at Pump Input (KW) 971 731
Efficiency (%) 81 81
Capacity (M3
/Hr) 617 615
Power at Pump Input (KW) 840 628
Efficiency (%) 80 80
Parameters CEP
Design Parameters
Parameters at 100% Load

CEP SIZING CRITERIA (Typical)
A. Flow calculations
Description Unit Max. flow Normal
Flow
Under frq Turbine
Bypass
1 Temperature of the condensate
0
C 40.00 45.00 40.00 40.00
2 Density of water kg/m
3
992.16 990.20 992.16 992.16
3 Condensate flow (HRSG with 0% BD) TPH 163.89 155.24 163.89 208.89
4 HRSG blow down (3% Con , 2% Int) TPH 8.19 7.76 8.19 10.44
5% 5% 5% 5%
5 Total flow ( 3+4) TPH 172.08 163.00 172.08 219.33
6 Flow with margin due to low
frequency
TPH NA NA 181.14 NA
7 Flow with 10% margin . Only 4% in
turbine bypass
TPH 189.29 NA NA 228.11
8 Required flow from each pump TPH 189.29 163.00 181.14 228.11
9 Required flow from each pump m
3
/hr 190.79 164.61 182.57 229.91
Say m
3
/hr 191 165 183 230

B. Head calculations
Flow
Under
frq
Turbine
Bypass
1 Deaerator operating pressure Kg/cm
2
1.23 1.23 1.23 1.23
2 Static head up to Deaerator nozzle(22 mts
above ground)
Kg/cm
2
2.20 2.20 2.20 2.20
2a Static head from ground level to eye of
impeller(4 mts)
Kg/cm
2
0.40 0.40 0.40 0.40
3 Pressure drop in Deaerator spray nozzles Kg/cm
2
0.20 0.20 0.20 0.20
4 Pressure drop in flow control valve Kg/cm
2
1.50 1.50 1.50 1.50
5 Pressure drop in CPH Kg/cm
2
4.36 3.92 4.36 5.89
6 Pressure drop in Flow nozzles (2 nos) Kg/cm
2
0.60 0.60 0.60 0.60
7 Pressure drop in piping Kg/cm
2
1.00 1.00 1.00 1.00
8 Pressure drop in Gland steam condenser Kg/cm
2
0.80 0.80 0.80 0.80
9 Pressure drop in SJAE Kg/cm
2
1.00 1.00 1.00 1.00
10 Margin on variable pressure drop {21% of
(sum of 3 to 9 above) or min 1.0 kg/cm
2
}
Kg/cm
2
1.99 NA NA 2.31
11 Total required discharge pressure. Kg/cm
2
15.28 12.85 13.29 17.12

C. Differential Head calculations
Flow
Under frq Turbine
Bypass
Net Differential head to be developed by
pump (B11-C6)
Kg/cm
2
14.84 12.37 12.85 16.64
Margin due to change in frequency i.e
applying factor {(50/47.5)
2
-1}
Kg/cm
2
NA NA 1.34 NA
Required differential pressure Kg/cm
2
14.84 12.37 14.19 16.64
Required differential pressure mwc 149.6 124.9 143.0 167.8
Say (rounding up to next 5mwc) mwc 150 125 145 170
D. Final parameters
Capacity of each pump m
3
/hr 191 165 183 230
Pump differentialhead required mwc 150 125 145 170
Head developed as per curve mwc 188 198 190 170

BFP SIZING CRITERIA (Typical)
A. Flow calculations
Flow
Under
frequency
Transient
Condition
1 Temperature of the feed water
0
C 105 105 105 105
2 Density of water kg/m
3
954.74 954.74 954.74 954.74
3 HRSG capacity ( with super heater
spray built in)
TPH 43.60 41.20 43.60 43.60
4 HRSG blow down (3% Con , 2%
Intermittent)
TPH 2.18 0.82 2.18 2.18
5 Total feed water flow
requirement(3+4)
TPH 45.78 42.02 45.78 45.78
5 Flow with margin due to low
frequency
TPH NA NA 2.41 NA
6 Feed water flow with 20% margin
during transient operation
TPH NA NA NA 9.16
7 Capacity of each Pump TPH 45.78 42.02 48.19 54.04
8 10% design margin on flow
(allowance for ageing)
TPH 4.58 NA NA NA
9 Required flow from each pump TPH 50.36 42.02 48.19 54.94
10 SELECTED CAPACITY IN CMH m
3
/hr 53.00 44.00 50.00 58.00

B. Discharge Head calculations
Flow
Under
frequency
TRANSIENT
OPERATION
1 Highest safety valve set pressure Kg/cm
2
(a) 91.63 NA NA NA
2 Drum Operating Pressure Kg/cm
2
(a) NA 81 81 81
3 Over Pressure ( 3 %) Kg/cm
2
2.75 NA NA NA
4 Static pr. due to drum height (21.6 m)
{height) x sp.gravity/10 }
Kg/cm
2
2.06 2.06 2.06 2.06
5 Pr. Drop in Economizer Kg/cm
2
3.00 3.00 3.00 3.00
6 Pr. Drop in feed control station Kg/cm
2
1.50 1.50 1.50 1.50
7 Pr. Drop in discharge piping including
fittings, valves, etc.
Kg/cm
2
1.0 0.69 0.89 1.20
8 Pr. Drop in flow element Kg/cm
2
0.30 0.21 0.27 0.36
9 Pr. Drop in ARC valve at discharge Kg/cm
2
1.0 0.69 0.89 1.20
10 Total variable pressure drop (5+6+7+8+9) Kg/cm
2
6.80 6.09 6.55 7.25
11 Margin on variable pr. drop (21%)
(min. 1 kg/cm2)
Kg/cm
2
1.43 NA NA 2.31
12 Pressure at discharge of Pump
(1 + 2 + 3 + 4 + 10 + 11)
Kg/cm
2
(a) 140.67 89.15 89.61 90.32

C. Suction Head calculations
Flow
Under fr TRANSIENT
OPERATION
1 Pressure of De-aerator Kg/cm
2
(a) 1.23 1.23 1.23 1.23
2 Pr. due to Height of the De-aerator LWLL
from BFP suction nozzle
Kg/cm
2
(a) 1.38 1.38 1.38 1.38
3 Total of above (1+2) Kg/cm
2
2.61 2.61 2.61 2.61
4 Pr.drop in suction strainer-50% clogged
(normal pr. drop approx. 0.1 Kg/cm
2
)
Kg/cm
2
0.2 0.2 0.2 0.2
5 Pr. drop in suction piping, inclusive of
fittings, valves, etc
Kg/cm
2
0.20 0.14 0.18 0.24
6 Pr. loss on suction side of BFP (4+5) Kg/cm
2
0.40 0.34 0.38 0.44
7 Available pr. on pump section side (3 – 6) Kg/cm
2
2.21 2.27 2.23 2.17
8 Available NPSH (7 – 1) Kg/cm
2
0.98 1.04 1.00 0.94
mwc 10.26 10.92 10.50 9085
9 Considering margin between NPSHA &
NPSHR as minm. 2.5 m, the NPSHR of
the pumps shall be limited to max. ( 50
% for rated flow)
Kg/cm
2
5.13 8.42 8.00 7.35

D. Differential Head calculations
Flow
Under
frequency
Transient
Condition
Net Differential head to be developed by
pump
Kg/cm
2
102.46 86.88 87.38 88.15
Margin due to change in frequency i.e.
applying factor {(50/47.5)
2
-1}
Kg/cm
2
NA NA 9.44 NA
Required differential pressure Kg/cm
2
102.46 86.88 96.82 88.15
Required differential pressure mwc 1073.16 909.14 1014.07 923.25
Final selected differential pressure mwc 1074 910 1015 924
E. Final parameters
Capacity of each pump m
3
/hr 53.00 44.00 50.00 58.00
Pump differentialhead required mwc 150 125 145 170

PROPER SELECTION OF EQUIPMENT
➢ Pumps are selected based on Parameters :
- pump flow rate
- total dynamic head
- operating temperature
- suction pressure / NPSH available
➢ Optimum pump input parameters would help in the
selection of right pump model
➢ The best efficiency shall preferably be between design
and normal point. Design capacity shall be within 80-
110% of the best efficiency capacity
➢ Pumps shall have stable Q-H characteristics
➢ Continuous head rise to shut off of atleast 10%
preferred for parallel operation

TYPES OF CENTRIFUGAL PUMPS
• VOLUTE CASING PUMP
• DIFFUSER VANE PUMP
Based on type of casing, Centrifugal Pumps are classified as :

• VOLUTE CASING PUMP :
- Kinetic Energy of the fluid is converted into Pressure
Energy by the Volute Casing itself .

• DIFFUSER VANE PUMP :
- Kinetic Energy of the fluid is converted into Pressure
Energy by a set of stationary diffusing vanes
surrounding the Impeller periphery.
- This Pump is of higher efficiency than Volute Casing
Pump.
- This construction balances radial reactions on the Rotor.

TYPES OF CENTRIFUGAL PUMPS
• SINGLE-STAGE PUMP :
- The head is developed by a single Impeller.
• MULTI-STAGE PUMP :
- The head is developed by two or more Impellers
operating in series, each taking its suction from
the discharge of the preceding Impeller.
Based on number of stages (i.e., no. of Impellers), Centrifugal
Pumps are classified as :

TYPES OF IMPELLERS
• RADIAL FLOW IMPELLER
• MIXED / DIAGONAL FLOW IMPELLER
• AXIAL FLOW IMPELLER
Based on the major direction of flow with reference to the axis of
rotation, Impellers are classified as :

• RADIAL FLOW IMPELLER :
- The fluid flows through the Impeller in a radial
direction.
- Low Specific Speed.

• AXIAL FLOW IMPELLER :
- Fluid flows through the Impeller in an axial direction
(i.e., parallel to the Shaft axis).
- High Specific Speed.

• MIXED/DIAGONAL FLOW IMPELLER :
- Fluid flows through the Impeller in axial as well as
radial direction.
- Medium Specific Speed.

• SPECIFIC SPEED :
- It is the speed of a geometrically similar Pump which
delivers one unit of Capacity against one unit of total
Head.
- It is generally used for comparison between various
types of Centrifugal Pumps.
- It is expressed symbolically as
NS = ( N Q ) / H3/4
where N is Speed, Q is flow rate & H is the Head.
- It determines the type of Impeller.
- It’s value varies from 30 to 1000 for Centrifugal Pumps.
➢ Radial Flow Impeller =30-290
➢ Mixed Flow Impeller = 290-440
➢ Axial Flow Impeller = 440-1000

COMPARISION BETWEEN RADIAL, MIXED & AXIAL FLOW IMPELLERS
PUMP TYPE
SL.
No.
FEATURES
RADIAL MIXED AXIAL
01 FLOW W.R.T. SHAFT AXIS PERPENDICULAR DIAGONAL IN LINE
02 SPECIFIC SPEED LOW MEDIUM HIGH
03 FLOW RATE LOW HIGH VERY HIGH
04 HEAD VERY HIGH MEDIUM LOW
05 SPEED HIGH LOW VERY LOW
06 EFFICIENCY NORMAL HIGH VERY HIGH

• SINGLE-SUCTION IMPELLER
• DOUBLE-SUCTION IMPELLER
Based on the flow into the suction edges of the vanes, Impellers are
classified as :

• SINGLE-SUCTION IMPELLER :
- The fluid enters the suction eye of the Impeller on one
side only.

• DOUBLE-SUCTION IMPELLER :
- The fluid enters the suction eye of the Impeller
simultaneously from both sides.

• OPEN IMPELLER
• SEMI-CLOSED IMPELLER
• CLOSED IMPELLER
Based on the mechanical design, Impellers are classified as :

• OPEN IMPELLER :
- Consists of vanes without any form of side wall or
shroud.
- Disadvantage is structural weakness.

• SEMI-CLOSED IMPELLER :
- Consists of vanes with shroud or an Impeller back
wall.
- Vanes are located on the back of Impeller shroud to
reduce the pressure at the back hub & to
prevent the pumped foreign matter from becoming
lodged behind the Impeller.

• CLOSED IMPELLER :
- Consists of vanes and shrouds that totally enclose the
fluid path from the suction eye to the periphery.

• AXIALLY-SPLIT CASING TYPE
• RADIALLY-SPLIT CASING TYPE
Based on the Casing splitting type, Pumps are classified as :

• AXIALLY-SPLIT CASING :
- It refers to a Casing split in a plane parallel to the axis
of rotation.
- Both Suction & Discharge nozzles are located on
bottom half of the Casing so that the top half
may be removed for inspection & repair without
disturbing the Pump proper and Suction &
Discharge piping.

• RADIALLY-SPLIT CASING :
- It refers to a Casing split in a plane perpendicular to the axis of
rotation.
- It contains two Casings, the inner casing encloses the rotating
parts of Pumps and the outer casing encloses the inner casing.
- Suction & Discharge nozzles are an integral part of outer casing
and the internal pump assembly can be removed without disturbing
the piping connections.

CONSTRUCTIONAL FEATURES
OF BOILER FEED PUMP

DESIGN FEATURES OF BFP
Horizontal, Multi Stage, Barrel Casing, Single Suction,
Radial Flow.
High Efficiency.
Fully Cartridgised construction.
Stiff Shaft design.
Thermal shock capability. Hence no warm up.
Balance Brum and tilting pad Thrust Bearing for Axial
thrust.
First Stage Impeller erosion life : 40,000 hrs (minimum)
Shaft sealing by Mechanical Seals.
Compatible materials for rotating and stationary parts.

BOILER FEED PUMP CARTRIDGE
FEATURES :
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).
BFP CARTRIDGE IS TESTED FOR HYDRAULIC AND MECHANICAL PERFORMANCE AT
BHEL WORKS LIKE THE ORIGINAL PUMP.

FEATURES OF CARTRIDGE DESIGN
The Boiler Feed Pump Cartridge is a
completely shop assembled Pump except
the barrel (casing).
This does not involve extensive
assembly and skilled centering at site.
Total replacement of the cartridge can
be completed in a maximum of two shifts.

• PUMP CASING :
- 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.

• SUCTION GUIDE :
- It guides the fluid from suction pipe to the eye of the Impeller.
- It closes the drive end of Pump Casing and forms the suction
annulus.
- It is not secured to Pump Casing but held against an internal
shoulder in the casing by Ring Section Assembly, Discharge
Cover and Spring Disc.
- It is closed by DE Water Jacket and Mechanical Seal Housing.

• IMPELLER :
- It rotates the mass of fluid with the peripheral speed of
its vane tips, thereby developing the head required or
the Pump working pressure.

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

• RING-SECTION ASSEMBLY :
- 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.

• WEARING RING :
- It is provided in the clearance between rotating & stationary
components of the Pump in order to avoid the leakage.
- It increases the life of the parent components by avoiding direct
contact between them.
- The clearance is in the order of 0.2 to 0.4 mm.
- It can be put either on Impeller or Diffuser/Ring Section or both.
- If Wearing Rings are provided on both rotating & stationary
components, they should be of dissimilar hardness.
- It is made of special quality material with high anti-galling
properties.
- When the wearing ring clearance becomes double, the Wearing
Rings have to be renewed.

• ROTATING ASSEMBLY :
- It consists of Shaft, Impellers, Balance Drum, Thrust
Collar, rotating parts of Mechanical Seals and the
Pump Half Coupling.
- It is dynamically balanced.

➢ SHAFT :
➢ BALANCE DRUM :

• DISCHARGE COVER :
- It closes the NDE of Pump Casing and forms the balance
chamber.
- It is closed by NDE WaterJacket and Mechanical Seal Housing.
- A Spring Disc is located between the last stage Diffuser and the
Discharge Cover Balance Drum Bush.
- Spring Disc provides the force required to hold the Ring Section
Assembly in place against DE of Casing.

• MECHANICAL SEAL :
- 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.

• SEAL HOUSING :
- It houses the Mechanical Seal.

• BEARINGS :
- They support the Pump Rotor.
- They keep the Shaft or Rotor in correct alignment with
stationary parts under the action of radial and axial
loads.
They are of two types :
➢ Line Bearings
➢ Thrust Bearings

➢ Line Bearings :
- They give radial positioning to the rotor.
They are of two types :
* Antifriction Bearings
* Sleeve Bearings

➢ Thrust Bearings :
- 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.

• BEARING HOUSINGS :
- They house Journal Bearing at the DE side and both Journal &
Thrust Bearings at the NDE side.
- These are in the form of cylindrical castings split on the horizontal
Shaft axis, located one each at DE & NDE sides of the Pump.
- These are secured to the Bearing Housing Brackets by studs and
nuts.
- Top & bottom halves of the Bearing Housings are secured together
by studs and nuts and located by dowel pins.
TOP HALF BOTTOM HALF

• BASE PLATE :
- It furnishes the mounting surfaces for the Pump feet that are
capable of being rigidly attached to the foundation.
- It may be Individual Frame for each equipment.
- It may be Common Frame on which all the equipments are
mounted.

• COUPLINGS :
- Centrifugal Pumps are connected to their drives through
either rigid or flexible couplings.
➢ Rigid Coupling :
- It does not permit either axial or radial relative motion
between the driving and the driven shafts.
- Used in Vertical Pumps.

➢ Flexible Coupling :
- It transmits the torque from the Driving Shaft to the
Driven Shaft.
- It allows minor misalignment (both angular & parallel).
It is of the following types :
❖ Pin and Bush Coupling
❖ Lovejoy Coupling
❖ Gear type lubricated Coupling
❖ Diaphragm/Spacer type Coupling

❖ Pin and Bush Coupling :
❖ Lovejoy Coupling :

❖ Gear type lubricated Coupling :

❖ Diaphragm/Spacer type Coupling :

BFP TRAIN WITH COMMON FOUNDATION FRAME :

OF BOILER FEED BOOSTER
PUMP

DESIGN FEATURES OF BP
 Horizontal, Single Stage, Double Suction, Axial Split
Casing, Radial Flow.
 Double Suction Impeller for minimum NPSHR.
 Shaft sealing by Mechanical Seals.
 Compatible materials for stationary and rotating parts.

OF CONDENSATE EXTRACTION
PUMP

DESIGN FEATURES OF CEP
 Vertical, Multi Stage, Multi-Shaft.
 Can type construction with suction nozzle integral with Canister.
 Double Suction first stage Impeller for minimum NPSHR.
 Balancing holes and tilting pad Thrust Bearing for Axial Thrust.
 Cutless rubber line bearings with axial flutes.
 Shaft sealing by PTFE rope packing / Mechanical Seals.
 Compatible materials for stationary and rotating parts.

• FIRST STAGE PUMP ASSEMBLY :
- It consists of Pump Casing, a Double Suction Impeller
and a Suction Bell Mouth.
• SECOND TO LAST STAGE PUMP ASSEMBLIES :
- It consists of Pump Casings and Single Suction
Impellers.

• HEAD PIECE :
- It incorporates the discharge and suction branches
and supports Thrust Bearing Housing & Driving Motor.
- It is sealed where the Shaft passes through Stuffing
Box which incorporates soft packing and a Lantern
Ring.
- Apertures are provided on Headpiece for accessing
Coupling, Thrust Bearing and Stuffing Box.
- An air vent pipe is incorporated in the Headpiece for
connection to the condenser tank.
• CUTLESS RUBBER BEARINGS :
- It supports the Pump Shaft & the Intermediate Shafts.
- The Rubber is of synthetic nitrile grade with inherent
ability to resist the abrasion.

• FOUNDATION RING :
- It consists of a circular flanges with sufficient number of
foundation bolt holes drilled on the lower flange.
- The top flange is provided with holes for fixing the Headgear and
Canister.
- Foundation bolts passing through the lower flange are grouted to
the floor, thus fixing the Foundation Ring into the foundation.
• CANISTER :
- It is a fabricated tubular chamber which is closed at the bottom.
- A flange is provided at the top of the Canister.
- The flange is secured to the Foundation Ring, thus provides the
support for the Headpiece.

• STUFFINGBOX ASSEMBLY :
- A water thrower provides protection for the Thrust Bearing and
prevents the gland leakage from entering into the underside of
Thrust Bearing.
• THRUST & JOURNAL BEARING ASSEMBLY :
- It is mounted in the Headpiece.
- It absorbs the Pump hydraulic thrust and the weight of the Pump
Rotating Assembly.
- The thrust is absorbed by the tilting white metal faced Thrust pads.
- White metal lined Journal pads locate the shaft radially.
• CONNECTINGCOUPLING :
- It transmits the drive from the Motor to the Pump.
- It is of spacer type flexible Coupling.
- It accommodates a certain amount of Off-set & angular mis-
alignment and also free end float or vertical movement of the
Shafts.

MATERIALS OF CONSTRUCTION
➢ Pump Casing - Carbon Steel Forging (0.25 C, Mn Steel)
➢ Pump Shaft - 13% Cr Stainless Steel Forging with 1% Ni
➢ Impeller - 13% Cr 4% Ni Stainless Steel Casting
➢ Diffuser - 13% Cr 4% Ni Stainless Steel Casting
➢ Ring Section - 13% Cr 4% Ni Stainless Steel Casting
➢ Wearing Ring - Cr Ni Mo Corrosion Resistant Stainless Steel
➢ Suction Guide - 13% Cr 4% Ni Stainless Steel Casting
➢ Discharge Cover - Carbon Steel Forging 0.25 Mn
➢ Suction Branch - Carbon Steel Casting with 0.25 C, 0.60 Si, 0.90 Mn
➢ Discharge Branch - Carbon Steel Forging
➢ Water Jacket - 13% Cr 4% Ni Stainless Steel Casting
➢ Bearing Housing - Carbon Steel Casting with 0.25 C, 0.60 Si, 0.90 Mn
➢ Seal Housing - 13% Cr 4% Ni Stainless Steel Casting
BOILER FEED PUMP (Typical)

➢ Balance Drum - Stainless Steel Forging
➢ Journal Bearing - Mild Steel / White Metal
➢ Thrust Bearing - Steel
➢ Mechanical Seal - Steel
➢ Spring Disc - Corrosion Resistant Stainless Steel
➢ Thrust Collar - Alloy Steel
BOILER FEED PUMP (FK 6D 30)

➢ Pump Casing - Carbon Steel Casting with 0.25 C, 0.60 Si, 0.90 Mn
➢ Pump Shaft - 13% Cr Steel Bar with 1% Ni
➢ Impeller - 13% Cr 4% Ni Stainless Steel Casting
➢ Wearing Ring - Cr Ni Cu Mo Corrosion Resistant Stainless Steel
➢ Bearing Housing - Carbon Steel Casting with 0.25 C, 0.60 Si, 0.90 Mn
➢ Journal Bearing - Mild Steel / White Metal
➢ Thrust Collar - Carbon Steel with Chromium plating
BOILER FEED BOOSTER PUMP (TYPICAL)

➢ Pump Casing - Cast Iron
➢ Pump Shaft - 13% Cr Steel Bar with 1% Ni
➢ Impeller 1st stage - 13% Cr 4% Ni Stainless Steel
Casting
➢ Impeller other stages - Aluminium-Bronze
➢ Wearing Ring - 17% Cr Ni Stainless Steel
➢ Canister - Structural Steel IS:2062
➢ Suction Bellmouth - Carbon Steel Casting
CONDENSATEEXTRACTION PUMP (Typical )

Optimisation of Materials of construction
➢ Bronze
➢ Cast iron
➢ Cast steel
➢ 400 series Stainless steel
➢ 300 series Stainless steel etc.
Choice of materials available :

Selection criteria for materials :
•corrosion resistance
•wear resistance
•cavitation resistance
•casting & machining properties
•endurance limit
•notch sensitivity
•galling characteristics
•cost optimisation

Conclusion
• Optimum selection of pump model, based on
hydraulic design, construction requirements, and
choice of appropriate material selection results in :
– Most efficient pump for the application
– lower operating costs &
– lower cycle times for assembly and maintenance
• Hence utmost attention may please be given for the
optimisation of the above criteria

OF COOLING WATER PUMP

DESIGN FEATURES OF CWP
 Vertical, Single Stage, Multi-Shaft, Mixed or Axial
Flow.
 High sustained Efficiency.
 Cutless rubber line bearings with axial flutes.
 Tilting pad Thrust Bearing for Axial Thrust.
 Shaft sealing by PTFE rope packing.
 Specially designed Bellmouth.
 Compatible materials for long life.

DESIGN FEATURES OF CWP
 Options for :
Pullout / Non-Pullout design
Single / double foundation
Non reversible ratchet
Shaft enclosing tube
Thrust block at discharge bend
 System study for Sump Model & Pressure Surge

• IMPELLER :
- It is a semi-open type, mixed flow & dynamically
balanced.
- It does not have hydraulic thrust balance holes.
- It is made up of Stainless Steel.

• PUMP CASING :
- It is also known as Diffuser.
- It converts the Kinetic energy of the fluid into Pressure
energy.
- It houses the Bearing body, into which the Cutless
Rubber Bearing is fitted in.
- It is a grey iron casting.

• BELLMOUTH :
- It guides the flow of water into the Impeller.
- It houses anti-swirl radial ribs to break the swirls before
water entering into the Impeller.
- The suction bell inlet diameter is so chosen that water
velocity is within 1.5 m/sec.
- It is made up of grey iron.

• COLUMN PIPE :
- It connects the Pump Casing and the Discharge Elbow.
- Water is lifted from the Pump Casing through this pipe.
- It houses the Guide Bearing for the Shafts.
- The entire length of the Column Pipe is split into 3 parts
for the sake of easy handling :
Element-I , Element-II & Element-III
- These elements are made up of Mild Steel.
• DISCHARGE ELBOW :
- It deflects water from the vertical Column Pipe to the
horizontal Discharge piping.
- It houses Stuffing Box where the Shaft Sealing is
achieved through Gland Packing.
- It is made up of Mild Steel plates.

• SUSPENSION :
- It offers a base for the Motor Stool & the Pump Thrust
Bearing.
- This rests on the Foundation Frame & is connected to
the Discharge Elbow at its lower end.
• SHAFTS :
- The entire shaft is divided into 4 parts :
Pump Shaft , Intermediate Shaft , Head Shaft & Drive
Shaft.
- These 4 Shafts are joined together by means of 3 Muff
Couplings.
- The Drive Shaft is connected to the Motor Shaft at its
top end through a Flexible Coupling.
- All the 4 Shafts are made up of high tensile Stainless
Steel.

• MAIN COUPLING :
- It connects the Drive Shaft and the Motor Shaft.
- It is a Flexible membrane type coupling having high
degree of flexibility for mis-alignment.
• FOUNDATION PLATE :
- It is grouted in the operating floor.
- It transmits the forces from the Pump and Motor to the
foundation.

• TILTING PAD THRUST BEARING :
- It takes the hydraulic axial thrust of the Impeller & also
the weight of the Pump rotating parts.
- It is lubricated by oil.

• MOTOR STOOL :
- It supports the Motor & mounted on the Suspension.
- Windows are provided on it for attending the problems
on Thrust Bearing & Connecting Coupling.
- It is made up of Mild Steel.
• CUTLESS RUBBER BEARINGS :
- It supports the Pump Shaft & the Intermediate Shafts.
- The Rubber is of synthetic nitrile grade with inherent
ability to resist the abrasion.
- These bearings are capable of ‘DRY RUN’ for maximum
time of 10 seconds.

CIRCULATING WATER PUMP
DRY WELL WET WELL

Generally Pumps classification done on the basis of its mechanical configuration and their working principle.

Generally Pumps classification done on the basis of its mechanical configuration and their working principle.

Recommended

Recommended

More Related Content

Similar to Generally Pumps classification done on the basis of its mechanical configuration and their working principle.

Similar to Generally Pumps classification done on the basis of its mechanical configuration and their working principle. (20)

Recently uploaded

Recently uploaded (20)

Generally Pumps classification done on the basis of its mechanical configuration and their working principle.