MES COLLEGE OF ENGINEERING AND TECHNOLOGY

KUNNUKARA

HYDRAULIC MACHINESLABORATORY MANUAL

1

LIST OF EXPERIMENTS

1. Performance characteristics test on Pelton turbine at constant speed

2. Performance characteristics test on Francis turbine at constant speed

3. Performance characteristics of single stage Centrifugal pump

4. Performance characteristics of double acting Reciprocating pump

5. Load test on Pelton turbine

6. Load test on Francis turbine

7. Performance characteristic test on Hydraulic ram.

8. Performance characteristic test on Gear pump.

2

1.Performance characteristics test on Pelton turbine at constant speed

AIM:

To find the operating characteristics of pelton turbine at constant speed and at constant head& plot the following graph. 1. Efficiency Vs Output power. 2. Head Vs Output power.

Also calculate specific speed of turbine.

APPARATUS:

(a)Pelton turbine with loading arrangement. (b)Pumping unit to supply water at required head. (c)Venturi meter arrangement to measure discharge. (d)Pressure gauges arrangements. (e)Tachometer.

PRINCIPLE:

Pelton turbine is an impulse turbine that uses water available at high heads (pressure) for generation of electricity. All the available potential energy of water is converted into kinetic energy by a nozzle arrangement. The water leaves the nozzle as a jet and strikes the buckets of the pelton wheel runner. These buckets are in the shape of double cups, joined at the middle portion in a knife edge. The jet strikes the knife edge of the buckets with least resistances and shock and glides along the path of the cup, deflecting through an angle of 160 to 170 deg. This deflection of water causes a change in momentum of the water jet and hence an impulsive force is supplied to the buckets. As a result, the runner attached to the buckets moves, rotating the shaft. The specific speed of the pelton wheel varies from 10 to 100 rpm.

In the test rig the Pelton wheel is supplied with water under high pressure by a centrifugal pump. The water flows through a venture meter to the Pelton wheel. A gate valve is used to control the flow rate to the turbine. The venture meter with pressure gauges connected to it is used to determine the flow rate of water in the pipe. The nozzle opening can be decreased or increased by operating the spear wheel at the entrance side of turbine.

The turbine is loaded by applying dead weights on the brake drum. This is done by placing the weights on the weight hanger. The inlet head is read from the pressure gauge. The speed of the turbine is measured with a tachometer.

PROCEDURE:

3

Prime the centrifugal if necessary & start the pump after closing the inlet valve of turbine. Adjust the opening of spear valve & simultaneously regulate the inlet valve for bringing rated pressure (3Kg/cm2). After bringing the system in steady position take the manometer, gauge reading at no load. Load the turbine for different weights. Take the pressure gauge and tachometer reading for each trial. Release the load gradually & simultaneously close the inlet & switch off the pump motor to stop the turbine.

SAMPLE CALCULATION:To determine discharge:Venturimeter meter line pressure gauge reading =P1 = kg/sq.cm Venturimeter throat pressure gauge reading =P2 = kg/sq.cmPressure difference, h = (P1-P2) *10 m of water

Discharge of water in m3/s, Q =

Cd a1 a2√2gh

√a12−a22

Where,Coefficient of discharge of venture meter, Cd = 0.96Inlet area, a1 =3.14*D2/4Throat area, a2=3.14*B2/4Inlet dia, D=50mmThroat dia, B=30mm

To determine head:Turbine Pressure gauge reading = P = kg/sq.cmTurbine vacuum gauge = V = mm of HGTotal head H = P*10m of waterInput to the turbine;Input power in KW, Pi = γQH KWSpecific weight of water γ =9.81 KN/m3

Turbine outputBrake drum diameter, d1 = 0.20mRope diameter, d2=0.015mEquivalent drum diameter, D=0.20+0.015= 0.215mEquivalent drum radius R=D/2Hanger weight, Wo = 1kgWeight added = W1 = kgSpring Load = W2 = kgResultant load, W= (W1-W2+Wo) kgSpeed of the turbine, N = 1000 RPMTorque developed T= R*W*9.81 NMOutput power Po=2πNT/(60*1000) KWTurbine efficiency η=Po/Pi *100SAMPLE GRAPH

η

4

H

O/P Power

Specific speed of the turbine Ns =

N √PH5 /4

N = Speed of turbine in rpm.P = Output power corresponding to ηmax(from graph)H = Supply head corresponding to maximum efficiency (from graph).

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Effic

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yP1 P2 h

P H Q W1 W2 W T Po Pi η

Kg/cm2

m of H20

Kg/cm2

m of H2O

m3/sec

Kg Kg Kg Nm kW KW %

1 1

2 2

3 3

4 4

5 5

RESULT

5

INFERENCE

2.Performance characteristics test on Francis turbine at constant speed

AIM:To find the operating characteristics curve of Francis turbine at constant speed and plot the

graph.1) O/P Power Vs efficiency2) O/P Power Vs Head

APPARATUS:

a) Turbine fitted with loading arrangement.b) Pumping unit to supply water at the required head.c) Pressure gauge.d) Tachometer.

PRINCIPLE:The Francis turbine is a reaction turbine, which means that the working fluid changes pressure

as it moves through the turbine, giving up its energy. A casement is needed to contain the water flow. The turbine is located between the high-pressure water source and the low-pressure water exit, usually at the base of a dam.

The inlet is spiral shaped. Guide vanes direct the water tangentially to the turbine wheel, known as a runner. This radial flow acts on the runner's vanes, causing the runner to spin. The guide vanes (or wicket gate) may be adjustable to allow efficient turbine operation for a range of water flow conditions.

As the water moves through the runner, its spinning radius decreases, further acting on the runner. For an analogy, imagine swinging a ball on a string around in a circle; if the string is pulled short, the ball spins faster due to the conservation of angular momentum. This property, in addition to the water's pressure, helps Francis and other inward-flow turbines harness water energy efficiently.

PROCEDURE:Prime the centrifugal pump for supplying pressurised water to turbine. Start the pump after

closing the inlet valve of the turbine. Remove the load in brake drum & open the inlet valve to start the turbine. Adjust the inlet valve to start the turbine. Adjust the inlet valve for keeping the pressure rated .The rpm is measured using tachometer. After bringing the system in steady position take the manometer reading, gauge reading at no load. Load the turbine for different weights. Take tachometer reading & pressure gauge reading for each load. Release the load gradually simultaneously close the inlet valve & switch off the pump motor to stop the turbine.

SAMPLE CALCULATIONTo determine discharge:Venturimeter meter line pressure gauge reading =P1 = kg/sq.cm

6

Venturimeter throat pressure gauge reading =P2= kg/sq.cmPressure difference, h = (P1-P2) *10 m of water

Discharge of water in m3/s, Q =

Cd a1 a2√2gh

√a12−a22

Where,Coefficient of discharge of venture meter, Cd = 0.96Inlet area, a1 =3.14*D2/4Throat area, a2=3.14*B2/4Inlet dia, D=65mmThroat dia, B=39mm

To determine head:Turbine Pressure gauge reading = P = kg/sq.cmTurbine vacuum gauge = V = mm of HGTotal head H =(P+V/760)*10m of water

Input to the turbine;Input power in KW, Pi = γQH KWSpecific weight of water γ =9.81 KN/m3

Turbine outputBrake drum diameter, d1 = 0.20mRope diameter, d2=0.015mEquivalent drum diameter, D=0.20+0.015= 0.215mEquivalent drum radius R=D/2Hanger weight, Wo = 1kgWeight added = W1= kgSpring Load = W2 = kgResultant load, W= (W1-W2+Wo) kgTorque developed T= R*W*9.81 NMOutput power Po=2πNT/(60*1000) KWTurbine efficiency η=Po/Pi *100

Sample Graph

η

H

O/P Power

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Effic

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P1 P2 hP V H Q W1 W2 W T Po Pi η

Kg/cm2 m of H20

Kg/cm2

mm of Hg

m of H2O

m3/sec

Kg Kg Kg Nm kW KW %

1 1

2 2

3 3

4 4

5 5

Result:

Inference:

8

3.PERFORMANCE CHARECTERISTICS OF RECIPROCATING PUMP

AIMTo determine the performance characteristics of the given reciprocating pump-set and

plot the following curves(i) Head v/s Overall Efficiency(ii) Head v/s Percentage slip

APPARATUS(a) The given piston pump with delivery and suction pipes.(b) Pressure and vacuum gauges in delivery and suction sides(c) Arrangement to measure discharge(d) Energy-meter connected in the supply line to measure the input power(e) Stopwatch

PRINCIPLEIn general, a pump may be defined, as a mechanical device which when interposed in

a pipe line, converts mechanical energy supplied to it from some external source into hydraulic energy thus resulting in the flow of liquid from the lower to the higher potential/head.

Reciprocating pump has a plunger (piston) which moves to and fro in a closed cylinder. The cylinder is connected to suction and delivery pipes and fitted with non-return valves to admit the liquid in one direction only. The suction non-return valve allows the liquid only to enter the cylinder and the delivery non-return valve allows the liquid only to escape from the cylinder to the delivery line.

The piston is connected to a crank by means of connecting rod. As the crank is rotated at uniform speed by a prime mover, the plunger moves to and fro thus creating continuous flow of liquid.

SAMPLE CALCULATION

Actual Discharge, Qa= Aht m3/s

Where, A= area of collecting tank in m2

t=Time taken for h cm rise of waterin collecting tank in sec

Supply Head, H=10(P+ V760

)m of water

WhereP=Pressure gauge Reading in Kg/cm2

V=Vacuum gauge Reading in mm of Hg

Output Power, Po = γQaH = KW

9

Where, =Specific weight of water = 9.81 KN/m3

Qa = Actual Discharge in m3/s H = Supply head of water in m

Input power, Pi = 3600(¿m)ntk

¿KW

Where n =No. of blinking of energy-meter disc.k =Energy-meter constant in blink/ KWht =Time for n blinking of the energy-meter

disc in secm =Efficiency of motor

Efficiency, =PoPi

* 100 %

Theoretical Discharge, Qt = 2LaN

60 m3/s

Where, L= stroke length of the piston in m a =Area of cylinder in m2

N=Speed of crank in rpm

Percentage slip, S = Qt−Q a

Qt*100%

Constants(a) Area of collecting tank = 0.4 x 0.4 m2

(b) Energy-meter constant = 3200 rev/KWh(c) Stroke length of pump = 50 mm(d) Cylinder diameter = 40 mm

PROCEDURE

Open the delivery valve for maximum discharge and start the pump. Keep the delivery valve for maximum discharge and note the time taken for rise of 10cm of water in the collecting tank. Take the vacuum and pressure gauge readings. Note the time taken for 10 revolutions of the energy-meter disc. Repeat the experiment for different delivery heads by adjusting the delivery valve. The speed of the crank is noted with the help of tachometer. After taking the observation, open the delivery valve to the full and switch off the pump.

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Perc

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ge S

lip

P V H t T N Qa Qt Pi Po η S

Kg/cm2mm of Hg

m of water s s rpm m3/s m3/s K

W KW % %

12345

SAMPLE GRAPH

η

% slip

HeadRESULT

INFERENCE

11

4. CONSTANT SPEED CHARECTERISTICS OF CENTRIFUGAL PUMP

AIM

To determine the constant speed characteristics of the given centrifugal pump-set and plot the following curves

(a) Head v/s Discharge(b) Overall efficiency v/s Discharge(c) Output power v/s Dischage.

APPARATUS

(a) Centrifugal pump fitted with delivery suction pipe (b) Collecting tank to measure discharge(c) Pressure and vacuum gauges(d) Energy-meter connected to the supply line to measure input power (e) Stopwatch.

PRINCIPLE

The centrifugal pump falls into the category of rotodynamic pumps. In this pumps, the liquid is made to rotate in a closed chamber (volute casing), thus creating the centrifugal action which is gradually builds the pressure gradient towards outlet, thus resulting in the continuous flow. But, their hydraulic heads per stage at lower flow rates is limited, hence not suitable for very high heads compare to reciprocating pumps of same capacity. But, still in most cases, this is the only type of pump which is being widely used for agricultural applications because of its practical suitability.

SAMPLE CALCULATION

Discharge (Q) is determined by,

Discharge, Qa = Aht m3/s

Where, A- area of collecting tank in m2

t – Time taken for h cm rise of water

Output power (Po) is determined byOutput Power, Po = γQaH = KW

Where, Po – output power in KW - Specific weight of water = 9.81kN/m3

Qa – Actual Discharge in m3/s H – Supply head of water in m

=10(P+ V760

)m of water

Input power (Pi) is determined by,

Input power, Pi = 3600(¿m)ntk

¿KW

Where, n – No. of blinking of energy-meter disc.

12

K – Energy-meter constant in blink/ KWht – Time for n blinking of the energy-meter

disc in secm - Efficiency of motor

Efficiency, =PoPi

*100

Constants(d) Area of collecting tank = 0.5 x 0.5 m2

(e) Energy-meter constant = 3200 blink/KWh(f) Efficiency of motor = 80%

PROCEDURE

To start the pump, close the delivery valve and prime the pump. After starting the pump, open the delivery valve and take the pressure gauge reading, vacuum gauge reading. Also note down the time required for n revolution of energy-meter disc for a particular discharge. Take time required for h cm rise of water in the collecting tank. Repeat the experiment for different discharges. After taking all the observations, close the discharge valve and switch off the supply to the pump-set.

OBSERVATION COLUMN

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i

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, Po

Effic

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Kg/

cm2

mm of

Hg

m of

waters s m3/s KW KW %

1

2

3

4

5

6

7

Mean efficiency, =

13

Pi

η

H

Discharge

RESULT

INFERENCE

14

Load test on Pelton turbine

AIM:

To conduct load test and to find the operating characteristics of pelton turbine& plot the following graph. 1. EfficiencyVsOutput power. 2. HeadVsOutput power.

APPARATUS:

(a) Pelton turbine with loading arrangement. (b)Pumping unit to supply water at required head. (c)Venturimeter arrangement to measure discharge. (d) Pressure gauges arrangements. (e)Tachometer.

PRINCIPLE

To determine discharge:Venturimeter meter line pressure gauge reading =P1 kg/sq.cmVenturimeter throat pressure gauge reading =P2 kg/sq.cmPressure difference, h = (P1-P2) *10 m of water

Discharge of water in m3/s, Q =

Cd a1 a2√2gh

√a12−a22

Where,Coefficient of discharge of venture meter, Cd = 0.96Inlet area, a1 =3.14*D2/4Throat area, a2=3.14*B2/4Inlet dia, D=50mmThroat dia, B=30mm

To determine head:Turbine Pressure gauge reading = P kg/sq.cmTotal head H = P*10m of water

Input to the turbine;Input power in KW, Pi =γQH KWSpecific weight of water γ =9.81 KN/m3

Turbine outputBrake drum diameter, d1 = 0.20mRope diameter, d2=0.015mEquivalent drum diameter, D=0.20+0.015= 0.215mEquivalent drum radius R=D/2

15

Hanger weight, Wo = 1kgWeight added = W1gSpring Load = W2kgResultant load, W= (W1-W2+Wo) kgTorque developed T= R*W*9.81 NMOutput power Po=2πNT/(60*1000) KW

Turbine efficiency η=Po/Pi *100

PROCEDURE:

Prime the centrifugal if necessary & start the pump after closing the inlet valve of turbine. Adjust the opening of spear valve & simultaneously regulate the inlet valve for bringing rated pressure. After bringing the system in steady position take the manometer, gauge reading at no load. Load the turbine for different weights & make the speed constant. Take the pressure gauge reading for each trial. Release the load gradually & simultaneously close the inlet & switch off the pump motor to stop the turbine.

SAMPLE GRAPH

η

H

O/P Power

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P1

P2

hP H Q W1 W2 W T N Po Pi η

Kg/cm2

m of H20

Kg/cm2

m of H2O

m3/sec

Kg Kg Kg Nm rpm kW KW %

1

16

2

3

4

5

RESULT

INFERENCE

17

Load Test on Francis turbine

AIM:To find the operating characteristics curve of Pelton turbine at constant speed and at constant

head and plot the graph.3) O/P Power Vs efficiency4) O/P Power Vs Head

Also calculate the specific speed of the turbine.

APPARATUS:e) Turbine fitted with loading arrangement.f) Pumping unit to supply water at the required head.g) Pressure gauge.h) Tachometer.

PRINCIPLE:The Francis turbine is a reaction turbine, which means that the working fluid changes pressure

as it moves through the turbine, giving up its energy. A casement is needed to contain the water flow. The turbine is located between the high-pressure water source and the low-pressure water exit, usually at the base of a dam.

The inlet is spiral shaped. Guide vanes direct the water tangentially to the turbine wheel, known as a runner. This radial flow acts on the runner's vanes, causing the runner to spin. The guide vanes (or wicket gate) may be adjustable to allow efficient turbine operation for a range of water flow conditions.

As the water moves through the runner, its spinning radius decreases, further acting on the runner. For an analogy, imagine swinging a ball on a string around in a circle; if the string is pulled short, the ball spins faster due to the conservation of angular momentum. This property, in addition to the water's pressure, helps Francis and other inward-flow turbines harness water energy efficiently.

PROCEDURE:Prime the centrifugal pump for supplying pressurised water to turbine. Start the pump after

closing the inlet valve of the turbine. Remove the load in brake drum & open the inlet valve to start the turbine. Adjust the inlet valve to start the turbine. Adjust the inlet valve for keeping the speed of the turbine constant (2000rpm).The rpm is measured using tachometer. After bringing the system in steady position take the manometer reading, gauge reading at no load. Load the turbine for different weights and make the turbine to rotate at rated speed by adjusting the inlet valve. Take tachometer reading & pressure gauge reading for each load. Release the load gradually simultaneously close the inlet valve & switch off the pump motor to stop the turbine.

SAMPLE CALCULATIONTo determine discharge:Venturimeter meter line pressure gauge reading =P1 kg/sq.cmVenturimeter throat pressure gauge reading =P2 kg/sq.cmPressure difference, h = (P1-P2) *10 m of water

18

Discharge of water in m3/s, Q =

Cd a1 a2√2gh

√a12−a22

Where,Coefficient of discharge of venture meter, Cd = 0.96Inlet area, a1 =3.14*D2/4Throat area, a2=3.14*B2/4Inlet dia, D=65mmThroat dia, B=39mm

To determine head:Turbine Pressure gauge reading = P kg/sq.cmTurbine vacuum gauge =V mm of HGTotal head H =(P+V/760)*10m of water

Input to the turbine;Input power in KW, Pi =γQH KWSpecific weight of water γ =9.81 KN/m3

Turbine outputBrake drum diameter, d1 = 0.20mRope diameter, d2=0.015mEquivalent drum diameter, D=0.20+0.015= 0.215mEquivalent drum radius R=D/2Hanger weight, Wo = 1kgWeight added = W1gSpring Load = W2kgResultant load, W= (W1-W2+Wo) kgTorque developed T= R*W*9.81 NMOutput power Po=2πNT/(60*1000) KWTurbine efficiency η=Po/Pi *100

Sample Graph

η

H

O/P Power

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P1 P2 hP V H Q W1 W2 W T Po Pi η

Kg/cm2 m of H20

Kg/cm2

mm of Hg

m of H2O

m3/sec

Kg Kg Kg Nm kW KW %

1 1

2 2

3 3

4 4

5 5

Result:

Inference:

20

Performance Characteristic Test on Hydraulic Ram

Aim

To conduct performance test on hydraulic ram and to find the efficiency

Apparatus

Hydraulic Ram test rig, stop watch, measuring jar.

Principle

Water from a supply tank kept at 2M height falls through a 1”-pipe line to the

Hydraulic Ram, through a control valve. A delivery pressure gauge, a waste water -collecting

tank with gauge glass scale fittings, and measuring jar for useful water are provided to

measure the output of the Hydraulic Ram. The ram is mounted on a stand for easy operation.

Continuous water supply to the supply tank is to be provided so as to maintain the head.

The Hydraulic Ram unit consisting of two chambers connected by pipefitting. The

smaller chamber house a drive valve (Ram) and the bigger one a delivery valve with air

cushion. A spindle provided on the Ram for initial starting of the Ram.

When the supply valve is opened waters flows down through the supply pipe and out

through the Ram. When the flow is fast enough the Ram snaps shut sending a powerful water

hammer or pressure wave along the pipe. This force some water through the delivery valve

and the water gets pumped out.

This pressure wave also traverse up the delivery pipe producing slight suction in Ram

and the water goes out through waste water end of the Ram. The whole cycle then repeats

automatically thus a small quantity of total water supplied gets pumped out to a greater

height. The delivery head is measured by a pressure gauge provided.

PROCEDURE:

1. Ensure the supply head is maintained constant.

2. Close the outlet valve provided after the pressure gauge.

3. Allow the water to flow down to the Ram and through the wastewater end.

21

4. Operate the Spindle provided on the Ram up and down till the Ram starts

automatically.

5. Open the outlet delivery valve and measure the water getting pumped using a

measuring jar (q).

6. Collect the wastewater and measure (Q)

7. Measure the supply head (H).

8. Measure the delivery head on the pressure gauge (h) in meters of water column.

Sample Calculation

Time for collecting 1 Litres of water = t sec

Delivery from ram,q =.001/t m3/sec

Time for 10 cm rise of water = k sec

Waste water discharge =A*10/k

Where A= area of collecting tank

Delivery pressure gauge reading =Pd kg/cm2

Delivery Head,h = Pd*10 m of water

Supply pressure =Ps Kg/cm2

Supply Pressure Head, H =Ps* 10 m of water

The efficiency of the Ram.= q .h / (Q+q) H.

Result

Inference

22

5. Performance characteristic test on Gear pump.

OBJECTIVES:

1. To determine the efficiency 2. Plot the characteristic curves of the given gear pump.

a) Head Vs Dischargeb) Head vs Efficiency

APPARATUS

1. Gear pump2. Collecting Tank3. Pressure Gauge4. Metre scale5. Stop watch6. Energy meter7. Driving unit

SPECIFICATIONS

Collecting tank dimensions

Length: 0.4 m

Breadth: 0.4 m

Energy meter constant:1600 Imp/KWh

Specific gravity of oil: 0.9

Specific weight of oil (W): 8829 N/m3

Specific gravity of mercury: 13.5

1 Kg/cm2 = 11.11 m of oil.

1 mm of Hg = 0.0151 m of oil.

23

PROCEDURE

Open the delivery valve for maximum discharge and start the pump. Keep the delivery valve open for maximum discharge and note the time t for the h cm rise

of oil in the measuring tank. Take the vacuum and pressure gauge reading. Note the time T for n no. of revolution of the energy meter. Repeat the experiment for different delivery head ranging from minimum to maximum

discharge by adjusting the delivery valve. After taking the observations, fully open the delivery valve and switch off the pump set.

SAMPLE CALCULATION:

A – Area of the collecting tank (m2)

h – Rise of oil level in collecting tank (m)

t – Time taken for ‘h cm’ rise of oil in collecting tank (s)

Hs = Suction head (m)

Hs = Ps x 0.0151 m of oil

Hd = Delivery head (m)

Hd = Pd x 11.11 m of oil

Z = Datum head (m)

Pd = Pressure gauge reading (Kg/cm2)

Ps = Vacuum gauge reading (mm of Hg)

n – No.of revolutions of energy meter disc

T – Time taken for ‘n’ no. of revolutions (s)

Emc – Energy meter constant

W – Specific weight of oil (N/m3)

Qact - Actual discharge (m3/s)

H – Total head (m)

1. Actual discharge

24

Qact= A ht m3/sec

2. Total head

H = HS + Hd + Z3. Input power

Pi = n×3600T ×Emc KW

4. Output power

Po = (W x Qactx H)/ 1000 KW

5. Efficiency of the pump

ηp= PoPi×100

TABULATION

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head

Sucti

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ead

Tota

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Tim

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for h

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ris

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Disc

harg

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Out

put p

ower

Inpu

t pow

er

effici

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hd hd hs hs H t T Q Po Pi η

Kg/cm2 m of oil

mm of Hg

m of oil

m of oil sec sec m3/sec KW KW %

RESULT

INFERENCE

25