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1. Topic V: Pumps and Pumping of Liquids
Pumps and pumping of liquids

2. Topic V: Pumps and Pumping of Liquids
•Pumps:Devicesforsupplyingenergyorheadtoovercomeenergy
losses.
•Asshownintheprevioustopic,ifthepumpisplacedbetweentwo
points1and2inapipeline,themechanicalenergybalance
becomes:  
fp
ww
PP
uuzzg 



122
1
2
212
2
1 :
p
w
specificworkdonebypumpontheliquid
•Nopumpisnot100%efficient,theefficiencyofthepumpis
definedas:
Where isthetotalspecificworksuppliedtothemotorofthe
pump.total
p
total
p
total
p
W
w
W
wm
W
w




 totalW

3. Topic V: Pumps and Pumping of Liquids:
:
:
total
p
W
w
Qm



Power added to the liquid by the pump
Power supplied to the motor of the pump
Mass flow rate of the pumped liquid

4. Topic V: Pumps and Pumping of Liquids
Example.Themotorwhichdrivesapumpissuppliedby2.8
horsepower.Thepressureatthesuctionsideofthepumpis30
psiaandthepressureatthedischargesideis100psia.Thepump
ispumping50gpm.Whatistheefficiencyofthepump?
P
1 P
2

5. Topic V: Pumps and Pumping of Liquids

6. Topic V: Pumps and Pumping of Liquids

7. Topic V: Pumps and Pumping of Liquids
•Pumpsystemheads:
A.Suctionhead(h
s):itworksinfavorofthepumpfs
s
ss
h
g
P
Zh 
 s
Z sP fsh
:Suctionstatichead,ifithasnegativevalueitwillbe
Suctionstaticlift.
:gasabsolutepressureabovetheliquidinthetankofthe
suctionside.
:headlossesduetofrictionandfittingsinthesuctionside.

8. Topic V: Pumps and Pumping of Liquids
•Pumpsystemheads:
B.Dischargehead(h
d):itworksagainstthepumpfd
d
dd
h
g
P
Zh 
 dZ dP fdh
:dischargestatichead,ifithasnegativevalueitwillbe
Suctionstaticlift.
:gasabsolutepressureabovetheliquidinthetankofthe
dischargeside.
:headlossesduetofrictionandfittingsinthedischarge
side.

9. Topic V: Pumps and Pumping of Liquids
•Pumpsystemheads:
C.Totalhead(h
p):
Thisdefinitioncanbeobtainedbyapplyingtheheadformof
mechanicalenergybalancebetweenonepoint(1)atthefree
surfaceofthesuctiontankandanotherpoint(2)atthefree
surfaceofthedischargetank:
h
fisthetotalheadlossesinthesuctionanddischargesides:g
w
hhh
p
sdp     
fdfsf
f
fp
sd
sd
hhh
uu
hh
g
PP
uu
g
ZZ





0;0
2
1
2
2
1
2
2


10. Topic V: Pumps and Pumping of Liquids
•Pumpsystemheads:
C.Totalhead(h
p):  )(
fdfsp
sd
sd
hhh
g
PP
ZZ 



Rearrangetheequationas:sd
fs
s
sfd
d
d
fdfs
sd
sdp
hh
h
g
P
Zh
g
P
Z
hh
g
P
g
P
ZZh


















11. Topic V: Pumps and Pumping of Liquids
D.NetPositiveSuctionHead(NPSH):0
g
P
hNPSH
v
s

Inordertoavoidcavitation(creatingvaporbubblesinthe
suctionside),theavailableNPSHisdefinedasbelow:
•TheavailableNPSHmustbegreaterthanzero,otherwise
cavitationwilloccurandthepumpwillbedamaged.
•NPSH
availableNPSH
required(givenbythemanufacturerof
thepump.
•Ifthesuctiontankisatboilingconditions( ):
Insuchconditions,thestaticsuctionheadmustbepositive
andgreaterthanh
fstohavepositiveNPSH.v
sPP fss
v
fs
s
s
v
s hZ
g
P
h
g
P
Z
g
P
hNPSH 


12. Topic V: Pumps and Pumping of Liquids
•Effectofflowrateonthesystemheads:
Asflowrateincresesh
fsandh
fdincresesthen:
-Thesuctionhead(h
s)willdecrease.
-Thedischargehead(h
d)willincrease.
-Thetotalhead(h
p)whichthepumpisrequiredtoimpart
theflowingliquidincreases.
-Theavailablenetpositivesuctionhead(NPSH)will
decrease.fs
s
ss
h
g
P
Zh 
 fd
d
dd
h
g
P
Zh 
 g
w
hhh
p
sdp 

13. Topic V: Pumps and Pumping of Liquids
Example.Determinesuctionhead
andtheavailableNPSHforthe
systemshowninthefigure.The
liquidreservoirisaclosedtankwith
apressureof-20kPaabovewaterat
70°C(thevaporpressureis31.2kPa,
densityis978kg/m3,andkinematic
viscosityis4.13×10
-7
m
2
/s).The
atmosphericpressureis100.5kPa.
Thewaterlevelinthetankis2.5m
abovethepumpinlet.Thepipesin
thesuctionsideD=00409mand.
pipewithatotallengthof12.0m.
Theelbowisstandard90
o
andthe
valveisafullyopenglobevalve.The
flowrateis95L/min.

14. Topic V: Pumps and Pumping of Liquids

15. Topic V: Pumps and Pumping of Liquids

16. Topic V: Pumps and Pumping of Liquids

17. Topic V: Pumps and Pumping of Liquids

18. Topic V: Pumps and Pumping of Liquids
ParametersInvolvedInPumpselection:
•When selecting a pump for a particular application, the
following factors must be considered:
1.The nature of the liquid to be pumped(viscosity, density,
suspended solids, corrosive,..etc)
2.The required capacity (volume flow rate)
3.The conditions on the suction (inlet) side of the pump
4.The conditions on the discharge (outlet) side of the pump
5.The total head on the pump (the term from the energy equation)
6.The type of system to which the pump is delivering the fluid.
such as hydraulic systems, heating systems, cooling systems, water distribution systems, or any
other system
7.The type of power source (electric motor, diesel engine, steam
turbine, etc.)
8.Space, weight, and position limitations
9.Environmental conditions
10.Cost of pump purchase and installation
11.Cost of pump operation

19. Topic V: Pumps and Pumping of Liquids
Typesofpumps:Pumpsaretypicallyclassifiedaseitherpositive
displacementorkineticpumps.

20. Topic V: Pumps and Pumping of Liquids
“Vane pump”
“Lobe pump”
“Gear pump”
Positive-Displacement(Rotary)Pump:

21. Topic V: Pumps and Pumping of Liquids
“Screw pump”
Positive-Displacement(Rotary)Pump:

22. Topic V: Pumps and Pumping of Liquids
“Progressing cavity pump”
Positive-Displacement(Rotary)Pump:

23. Topic V: Pumps and Pumping of Liquids
Positive-Displacement(Rotary)Pump:
“Peristaltic Pump”

24. Topic V: Pumps and Pumping of Liquids
Positive-Displacement(Reciprocating)Pump:
Diaphragm pump

25. Topic V: Pumps and Pumping of Liquids
Positive-DisplacementPump:
•Positive-displacementpumpsideallydeliverafixedquantityof
fluidwitheachrevolutionofthepumprotorordriveshaft.
•Mostpositive-displacementpumpscanhandleliquidsovera
widerangeofviscosities.
•Theoperatingcharacteristicsofpositive-displacementpumps
makethemusefulforhandlingsuchfluidsaswater,hydraulic
oilsinfluidpowersystems.
•Somedisadvantagesofsomedesignsincludepulsatingoutput,
susceptibilitytodamagebysolidsandabrasives,andneedfora
reliefvalve.

26. Topic V: Pumps and Pumping of Liquids
Reciprocating Pump Performance:
•Initssimplestform,thereciprocatingpumpemploysapiston
thatdrawsfluidintoacylinderthroughanintakevalveasthe
pistondrawsawayfromthevalve.
•Then,asthepistonmovesforward,theintakevalveclosesand
thefluidispushedoutthroughthedischargevalve.
•Suchapumpiscalledsimplex,anditscurveofdischarge
versustimeisillustratedinthenexttwoslides.

27. Topic V: Pumps and Pumping of Liquids
Piston Pump Performance:

28. Topic V: Pumps and Pumping of Liquids
Piston Pump Performance:

29. Topic V: Pumps and Pumping of Liquids
ميحرلا نمحرلا الله مسب
{ ْعَي ٌبوُلُق ْمُهَل َنوُكَتَف ِضْرَلأا يِف اوُريِسَي ْمَلَفَأ َهِب َنوُعَمْسَي ٌناَذآ ْوَأ اَهِب َنوُلِق ا
َّلا ُبوُلُقْلا ىَمْعَت ْنِكَلَو ُراَصْبَلأا ىَمْعَت لا اَهَّنِإَف ِروُُدصلا يِف يِت}
مقر ةيآ جحلا ةروس46
Heart is a reciprocating pump…….

30. Topic V: Pumps and Pumping of Liquids
Heart is a reciprocating pump…….

31. Topic V: Pumps and Pumping of Liquids
Blood pressure measurement:
Initiallythecuffisinflatedtoalevelhigher
thanthesystolicpressure.Thusthe
arteryiscompletelycompressed,thereis
nobloodflow,andnosoundsare
heard.Thecuffpressureisslowly
decreased. At the point
wherethesystolicpressureexceeds
thecuffpressure,thesoundsarefirst
heardandbloodpassesinturbulentflow
throughthepartiallyconstrictedartery.
soundswillcontinuetobeheardasthe
cuff pressure is further
lowered.However,whenthecuff
pressurereachesdiastolicpressure,the
soundsdisappearandbloodpassesin
laminarflow.
Normalbloodpressure:
Systolic:120mmHg
Diastolic:80mmHg

32. Topic V: Pumps and Pumping of Liquids
Characteristic Curves of Positive-Displacement Pumps
•Characteristicperformancecurvesofpositive-displacement
pumpsareusuallyplotsofcapacity,efficiency,andpower
versusdischargepressure.
•Aspressureisincreased,aslightdecreaseincapacityoccurs
duetointernalleakagefromthehigh-pressuresidetothelow-
pressureside.
•Volumetricefficiencyisameasureoftheratioofthevolume
flowratedeliveredbythepumptothetheoreticaldelivery,
basedonthedisplacementperrevolutionofthepump,timesthe
speedofrotation.

33. Topic V: Pumps and Pumping of Liquids
Characteristic Curves of Positive-Displacement Pumps
The figure below shows an example of such Characteristic
Curves :

34. Topic V: Pumps and Pumping of Liquids
KineticPumps:Kineticpumpsaddenergytothefluidby
acceleratingitthroughtheactionofarotatingimpeller.
•The most common type of kinetic pumps are the basic configurations
of a radial flow centrifugal pump:

35. Topic V: Pumps and Pumping of Liquids
Kinetic Pumps:
The basic design of radial, axial, and mixed-flow impellers:
•Thepropellertypeofpump
(axialflow)dependsonthe
hydrodynamicactionofthe
propellerbladestoliftand
acceleratethefluidaxially,
alongapathparalleltothe
axisofthepropeller

36. Topic V: Pumps and Pumping of Liquids
Kinetic Pumps:
•Examples of kinetic pumps are:
1.Jet Pumps
2.Submersible Pumps
3.Small Centrifugal Pumps
4.Vertical Turbine Pumps
5.Centrifugal Grinder Pumps

37. Topic V: Pumps and Pumping of Liquids
Kinetic Pumps:
“Deep-well jet pump”
“Shallow-well jet pump”

38. Topic V: Pumps and Pumping of Liquids
Kinetic Pumps:
“Portable submersible pump”
“Centrifugal pump with integral
motor”

39. Topic V: Pumps and Pumping of Liquids
Kinetic Pumps:
“Self-priming pump”
(1) Suction inlet casing
(2) impeller,
(3) mechanical shaft seal
(4) shaft.

40. Topic V: Pumps and Pumping of Liquids
Kinetic Pumps:
“Vertical-turbine pump”
“Centrifugal grinder pump”

41. Topic V: Pumps and Pumping of Liquids
Centrifugal pump and conservation of angular momentum:
In centrifugal pump, there is liquid rotation:

42. Topic V: Pumps and Pumping of Liquids
Property Piston pump Centrifugal pump
Capacity (Discharge flow rate) Low High
Discharge pressure High Low
Variable nearly constant Discharge flow rateDischarge pressure
Number of moving and wearing parts Many small
Nature of discharge flow Pulsating Steady
Work well on high-viscosity liquids Yes No
Work well on suspended –solid
solutions
No Yes
Angle between suction and discharge
lines
0
o
90
o
General comparison between piston and centrifugal pumps: