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Q.EC][PQ.OCATING
PUMPS

INTRODUCTION

leSS(?n 5 deals mainly with one of the·positive displacement pumps-the reciprocating

pumps. It presents and defines the different types of reciprocating pumps specifically the
steam or direct-acting reciprocating pumps and the indirect-acting reciprocating pumps.
The discussion also includes sample problems that apply the necessary equations In
the analysis and design computations involving these two types of pumps.
The section Key Terms and Concepts to Remember provides basic definitions,
principles, and related information on. reciprocating pumps, while a self-test and problem-
solving exercises serve ~o assess student comprehension.

LESSON OBJECTIVES

At the end of this lesson, the students should be able to:

• define displacement and reciprocating pumps;
• enumerate the different types of reciprocating pumps;
• differentiate direct-acting and indirect:ac!ing pu~ps; .
·ty the sizes of direct-acting and indirect-acting pumps; and
• speer . . ti
solve problems involving recrproca ng pumps.
• ana Iyze an d - _, _
 DEFINITIONS OF TERMS AND OTHER USEFUL INFORMATION
• A reciprocating pump Is a machine In which the pumping action Is occompfllheci
by the forward and backward movement of.a piston Inside a cylinder, usua11y
provided with valves. It Is classified as .a posltly~ dlspla~ement pump. .
• In 1840, Henry R. Worthington invent d the ~rst direct-acting reciprocaung atean,
7
pump used for feeding water Into boilers. . . . .
• A displacement pump is a pump in which energy_ 1s penod1ca11~ added by
,, application of force to one or more movable ~oundane~ of an~ des,~ed number .·
·,,l - : of enclosed, fluid-containing volumes. This results . in a direct increase in
'J
I · pressure, up to the value required to mov~ the fluid through valve or port into the
_. discharge line.
I

TYPES OF RECIPROCATING PUMPS •·

!
'!
To r~cepitulate, the types of reciprocating pumps are as follows:
A. Piston and plunger type reciprocating pumps
1. · Steam or Direct-acting, double-acting pumps
a. simplex pumps
b. duplex pumps
2. Power or ll)direct-actlng pumps
a. Single-acting pumps
I. simplex pumps
ii. duplex pumps
iii. triplex pumps · .
iv. multiplex pumps
b. Double-acting pumps
i. simplex pumps
. V\- ii. duplex pumps
·, -· iii. triplex pumps
Iv. multiplex pumps
. 8. Diaphragm-type reciprocating pumps
1. Simplex-type pumps
a. Fluid operated type
b. Mechanically operated type
2. Multiplex-type pumps
a. Fluld operated type
b. Mechanically operated type

CLASSIFICATION OF RECIPROCATING PUMPS IN TERMS OF

THE METHOD OF DRIVING THE WATER PISTON OR PLUNGER

1. Direct-acting reciprocating pump is a pump that is motivated by the force of steam

on the steam ~lston. The steam and water pistons are connected by a piston rod-
Any for~e apphed on the steam piston Is transmitted to the water piston. Steam ancl
water pistons are normally double-acting, which means that every stroke of th8
· water piston Is a delivery stroke.

~ IJ~ - = - ~ ~
 • ~eciprocating ~~mps may be ·of either ~he piston type or the f?lunger type.
Water

out

Steam in' Water Water

· in in
Figure ,5.1. Direct-acting Reciprocating Pumps

Cylinder and Piston Dimensions

· Example:

.2Q3 )(
~ )(
JQ5 rnrn
~ength of stroke (common to both cylinders)

I
i

I Diameter or bore of water cylinder_

Diameter of steam cylinder

2. Indirect-acting reciprocating pump is a pump in which water is driven by an electric

motor, internal combustion engine, steam turbine, gas turbine, or steam engine. It
is-also called a power pump. It has high efficiency and constant speed because of
- the type of drive. It is capable of delivering constant quantity of fluid against a variable
- he~d. It is either single-acting or double-acting.

• · The design of power pumps may be horizontal or vertical. _

Water
Connecting

·--- ~=-----_---- rod

',. . ;., _A Crank

in

Figure 5.2. Indirect-acting Reciprocating Pumps

 Cylinder and Piston Dimensions

Example:

..203...x 305mm
L------ Length of stroke
IL.- - - - - - - Diameter or bore of the cylinder

CLASSiFICATION OF RECIPROCATING PUMPS IN

TERMS OF THE NUMBER OF WATER CYLINDERS

1. Simplex pump - a reciprocating pump with one cylinder

2. Duplex pump - a reciprocating pump with two cylinders
3. Triplex pump - a reciprocating pump with three cylinders

FORMULAS

1. Direct-acting Pumps

a) . Approximate commercial speed of piston

V =1.38,/LF,
. where V = piston speed, m/min
L = length of stroke, mm
F 1 = temperature correction factor
= 1.00 for cold water
.••. = 0.85 for 32.2°C water
• = 0.71 for 65.5°C water
= 0.55 for 204.4°C water

b) Piston displacement

V. =~D 2 Vn
D 4
where VO = piston displacement, m3/min
D = diameter of water piston, m
V = piston speed, m/min
n = number of water cylinders
= 1 for simplex pump
= 2 for duplex pump
= 3 for triplex pump

c) Pump duty - the work done in the water cylinders expressed in N-m/million
joules · . ·

Pump d1,1ty = 9.807 mW (Hd - H,) X ae

1

----- . .- -: .,_. •r-------

=.::,_;;.----:~ - ~ . '· ~. ---
1000m, (h, :- h.)
~e.J.Cwdetioii~Ja Fl)!td M•~lll!t.!I\' ~ - ------
=-----~- -:::;:---~;-
---: :.-~---
~ -
 where mW= water pumped, kg/s
m, = s!eam used, kg/s .•
Hd = discharge head of pump m
H, = suction head of pump •~
~• : enthalpy of supply ste~m. kJ/kg
• - enthalpy of exhaust steam, kJ/kg .

d) Pump_duty In terms of N-m per 1 000 kg dry steam

Pump duty= ~807 mw (Hd - H,) 1O'

1000mI (hI -h)
e
x

where pum~ duty Is In N-m per 1000 kg dry steam

m, - ~ass flow rate of dry steam used, kg/s
Hd = d1sc~arge head of pump, m
Hd = suction head of pump, m
.., 2. Indirect-acting Pump

a) Rotative speed of directly coupled motor or the crank shaft

N =907.5.._
m .jL
where Nm = motor or crank shaft speed, rpm
L = length of stroke, mm
F1 = temperature correction factor

b) Piston displacement (rod neglected)

t.>l
V. = ~D2 Yn
0 4 .
" where VO = piston or volume displacement, ml/min
. L = length of stroke, m
D = bore or piston diameter, m
N = number of delivery strokes per minute
. = Nm' for single-acting pump
= 2N , for double-acting pump
n = i,u;;;ber of cylinders

c) Volumetric efficiency (for both direct-act!ng and indirect-acting pumps)

= actual volume flo~, ml/min(100 %)=..9.( 100 %)
11. Vo, ml/min . Vo

d) Slip (for both direct-acting and Indirect-acting pumps)

Sllp = 1 - .11. .

~ - - ~~ lf~PmCATIN N]MpCtltt.:
=
~ -.;.
~ ~~ ; ~ - ~ ~ ~ ~ - -C=
 ADVANTAGES AND DISADVANTAGES OF DIRECT-ACTING
RECIPROCATING PUMPS OVER CENTRIFUGAL PUMPS

Advantages
average
• The design is simpler and pumping action Is readily understood by an
mechan ic. ·
. ----fhe operation Is more flexible.
on.
__:---/•· ifne operation is fairly quiet and can be set on a slmple light f?undall
· ----· • It is not likely to become misaligned.
hundred
• It has a comparatively low initial cost and a capacity of up to several
liters per minute.

Disadvantages
• Oily exhaust steam
• Low thermal efficiency
• More inspection and maintenan_ce required

ILLUSTRATIVE PROBLEMS
. .
dimensi ons for a duplex, direct-acting steam pump for the
Ex 5.1) Select the suitable
is at 93"C;
following boiler services : 265 1pm against 0.863 Mpaa boiler pressures water
of water; water
boiler water level is 5.5 m above pump; pump is 2.0 m below source
head and pipe friction.
cylinder, D = L; and volumetric efficiency is 90%. Neglect velocity

i~
Find the water power.

Given: The figure shown:

..
0.863 Mpaa
D= .L

-rL------1
Q =265 lpm A
5.5 m
TJ. = 90%
r_..._---'Pump>------IJ_
-.L-2

. Required:
a) Suitable dimensions of duplex, direct-acting pump
b) Water power ·

I
 .
_a) Determination of suitable dimensions ·

, .Solving for the piston displacement, .

· PD= .9. J0.265 m /min) _. 3

3
.

Tlv . 0.90 -0.294 m /min= 294 x 109 mm3/min

, From the equation of PD,

PD =( *)o v *)o2
n =(
2
( 1.38 JC F,)
=(%)o (1380Ji:F )n, when V =1380 'J[ F
2
1 1

where V = 1.38 Jr F, ➔ m/min '

V = 1380 J[ F, ➔ mm/min
.
D=L .

. Then, PD=( i)0 (1380.✓DF,)n

2
=( ¾ )(✓0f (1380)F,n
• • Solving for D, where F, = 0.6783 (interpola!ed) ·
2 2

D=[ 4PD
1t{1380)F, n
ls=[ - 4(294)10s
1t{1380)(0.6783)(2)
ls =13~.94-132mm
·.

Therefore, the suitable size is D >< L = 132 >< 132mm. ANSWER

. : b) For the water power or pump theoretical work

• Solving for the TOH of the pump, ·HA + TOH = H8 + HLAB

P v2 _ P - V,2 .
2-+_A_+z ·+TOH=_ll_+-8-+Za
pg 2Q A pQ 2Q .
where VA = o· vB = o· & HLAB = o
I I

3
• Solving for the TOH, where, at 93°C, p = 963.2 kg/m ·

TOH= Pa -PA +(i . z ) J863000-101325) +( 5.5 _ 2) = 84 _11 m

pg B A 963.2(9.81) ~

' · •• 1
•, '

~ .E1_ ·tiBII I ~
~ . ,
 • Solving for the water power,

pgQ(TDH)
wp-.:.....::..~-....:.
' 1000
WP= (963.2)(9.81)(0.265/60)(84.11) = _ ' kW
3 51
.1000 .

Ex. 5.2) Results of a test on a 254 ,c 152 ,c 305 mm' duplex, direct-acting pump are as
· follows: Test time, 60 minutes; speed, 38 strokes per minute per cylinder; TOH is 76 m;
I
I, 82.2°C water;.water pumpe~ Is 22680 kg. Determine: a) volumetric efficiency; b) water
power; and c) slip. ·
Given: A 254 ,c 152 ,c 305 mm duplex, direct-acting pump

Time = 60 mlnut~s
Speed = 38 strokes per minute per cylinder
Water temperature = 02.2°c
Mass of water pumped = 22680 kg
n = 2
TOH = 76 m
Required:
a) Volumetric efficiency, Ev
b) Water power, WP
c) Slip
Solution:
• For the piston speed,

V = (0.305 m/stroke) (38 strokes per min per cylinder)= 11 .59 m/min

• For the piston displacement, .

'

2
PD= ( ~) 0 V n = ( ~ }o.152)2 (11.59)(2) = 0.4206 m3/min
• For the pump capacity, at 82.2°C, p = 970.3 kg/m 3

Q= 22680 kg =0.39 m3/min

3
(60 min)(970.~ kg/m )
. a) Solving for the volumetric efficiency

a (100%) = ( 0.4
Ev= PD o.39 ) (100%) = 92.72% ANSWER
206
 b) Solving for the water power

WP= pgQ(TDH)
1000
WP= (970.3)(9.81)(0.39/60)(76)
1000 . =4.7 kW

· c) Solving for the slip

_Slip= 1-e_, = (1-0.9272)100% = 7.28% ANSWER

ex. 5.3) Results of-a test on a 254 1C 152 IC 305 mm duplex, direct-acting pump are as
folloWS: Test time, 60 minutes; steam used 567 kg at 1.38 Mpaa saturated steam; exhaust
at0.101 Mpaa; speed, 38 strokes per minute per cylinder; water pumped, 22 680 kg; TOH,
76 mat 82oC water. Determine: a) volumetric efficiency; b) water power; and c) pump duty.

Given: A254 IC 152 IC 305 mm duplex, direct-acting pump

lime = 60 minutes
Mass of steam used = 567kg
· Pressure of saturated steam = 1.38Mpaa
Pressure of exhaust steam = 0.101 MPaa
Speed ' = 38 strokes per min per cylinder
Mass of water pumped = 22680kg
Total dynamic head, TOH = 76m
Number of cylinders = 2 cylinders
Temperature of water = 82°C

Requlmd:
a) Volumetric efficiency, e.
b) Water power, WP
c) Pump duty .

Soiution:
- • For the piston speed,

v = (0.305 m/stroke)(38 strokes per min per cylinder)= 11 .59 rn/min

• For the piston displacement, ·

PD=(~ )0 vn =(~ }o,1s2)2 (11.59)(2} =0.4206 m /min

2 3
 .• For the actual volume fl~ rate, at 820C, v, • 1.0305 ,c 10-1 m3/kg, r • 970.40
· . (22680 kg) 4· 3 kw.,,
. , Q=m._(v., ~= 60 min (1.0305x10 kg/m )=0.3895m'lmln

a) Solving for the volumetric efficiency

·•• ·£y % )=92.61%

=(p~ }100.%)~(~:!~~:}100_

b) Solvlng for the water power of the pump

' .. WP= pgQ(TOH)

. 1000
~ (970.40)(9.81)(0.3895/60)(76) = 4 _7 kW
1000

c) Solving for the pump duty

· 9.807m (H -H )
Pump duty = • d • x 108
. 100Q(m,)(h, -h.)

where Hd - H, TOH 76 m = =
• h1
.=
h . =. enthalpy of supply steam at 1.38 Mpaa and saturated = 2 789.6 k.Mv
enthalpy o~ exhaust saturated water. at 0.101 Mpaa = h,·= 417.46 kJI;
'

Therefore, .

Pump duty=
9.807(22 680)(76)108 N•
· =0.0126-----
m
. . 1000(567)(2 789.6-417.46) Million Joules

Ex. 5.4) What size of 1 750-rpm motor should be used to dri~e a 100 >< 200 mm single-
acting triplex power pump? Pump ·efficiency = 88%; mechanical efficiency .= 90%, Wh8l •
V-belt pulley diameter should be used? Water temperature = 11 0"C. ·TOH = 24.6 kg/cm2 =
258.69m .

. Given: Single-acting, triplex pump

. Nm= 1750 rpm hP = 88% TOH = 258.69 m ·
Dw=100mm hm =90% t = 110.°C
L = 200 mm e
- y
= 95%

Required:
a) Size of the driving motor
b) Size of the V~belt pulley
 utJOn' .. .
5"' From steam tables,.at 110°C,·v, := 1.0516
. x 10"3 m3/kg, r .= 950.932 kg/m'
I ' ~ •

(24.6 kg/cm2 )(10·000 cm 2/m 2 ) ·

. _ For the TOH, TOH= . · · = 258.69 m
. .. ., ·· . (950.932 kg~_m3 ) .- ·,
. . . .

· For the ~rankshaft.rpm, N= 9o7 F, =(907)(0.6587 ) =42.25 rpm ·..

·.· .• . .j[ · ✓ 200 ·
where F1 = 0.65~7 (interpolated) ·

For the piston displacement,

P~=( if'LNn=( i}o,10)'(~.20)(42.25){3)=0.199 m'/min .

For the actual volume flow rate,
•
.Q = (_PD) (eJ = 0.199 (0.95) = 0.189 m3/min

a) Solving for the brake power of the driving motor

Pump brake power,

WP pgC(TDH)
BP=-=
. Tip · 100011p, . . -
_ (950.932){9.81){0.189/60)(258.69) =8 _64 kW
- 1000(0.88)

The~. moi or brake power B~M'

BP. .= BP·= 8.64 =·9.60 kW
M 11m 0.90

. Therefore, use, say, a 10-kW motor. ANSWER

--- - -- - -- --- - - - -- ~ - -- ~ -
b) Solvlng for the V-belt pulley size

From machine design textbooks, the type

f V-belt to be used for a 9.6-kW drive
er Is section "B" at 1800 rpm.
1..~ .- ommended . range of small pitch
· diam~ter is from 13r to 188 mm. If the small
pitch diameter is 137 mm, the _cranksh~ft
pulley diameter, for single reduction 1s
137 x 41.42 = 5 675 mm or 5.675 m, which
is unrealistic. Multiple reduction by belt
drive is not recommended. (Note: 41.42 is
the speed ratio). .

KEY ,TERM f AND CONCEPTS TO REMEMB

ER:
• A reciprocating pump, also known as a piston pum
p, is a pump in which moUon and '
pressure are applied to the fluid by a reciproca
ting piston In a cylin~er. ..
• A piston rod is a rod that Is connected to the
piston, and either moves o_r is moved ·
by the piston.

• Piston speed is the distance traveled by a pisto

n in a given time usually exp'ressed
in fpm or mis.

• The volume that the piston in a cylinder displ

aces in a single stroke is known as
volume displacement. It is 'equal to the product
of the distance the piston travels ·..
(stroke) and the internal cross section of the cylin
der. ·
• A direct~acting pump is a displacement-recipr
ocating pump in which the steam or
power piston-is connected to the pump pisto
n by means of a rod, without crank.
motion or flywheel.

• A displacement pump is a_pulTlp that deve

lops its action through the alternate filling
and emptying of an enclosed volume in a pisto
n-cylinder system.
• . A positive displacement pump is a pump in
which a measured quantity of liquid is
entrapped in a space, its pressure raised, and is
delivered like a reciprocating piston
cylinder, rotary vane, gear, or lobe pumps. .
.
• A_ gea: pump is a rotary pump in whic_h two meshing
gear wheels rotate in opposite

• •
directions so that the liquid is entrained on one
side: · '
side and discharged on the other

Rotary pumps are displacement pumps that deliv

two members in rotational contact. er a steady flow by the action of

~~--~!d~~~~-~:~n_•·~~~~•eii~~~
 • A screw-type pump ls a displacement pump that raises llquld by means of helical
Impellers In_the pump casing. _ · - _ _.

• i duplex pump is a reqipro~ting pump with tw~-p~rallel cylinders.

• A submersible pump_is one in which the pump it~elf and 'i'ts electric driving_ motor
are together in a protective housing that permits the unit to operate underwater.

• Submersible pumps are either rotary, centrifugal, ~r reciprocating pumps.

' ,

• A, regenerative p_ump, also known as a turbine pump, has a rotating-vane device

that uses a combination of mechanical Impulse and centrifugal force to produce
high liquid heads at low discharge. -

• A vertical turbine pump, also known as a deep-weal pump, is a multi-stage centrifugal

· pump used for lifting water from deep and small-diameter wells. A surface electfjc
motor operates the shaft.

• A hydraulic machine is powere~ by a motor activated by the confined flow of a

stream of liquid, such as oil or water under pressure.

• _ A hydraulic motor is activated by water or other liquid under pressure.

• A jet pump is a pump in which an accelerating jet entrains a second fluid to deliver
. ,, it at elevated pressure .

•• The rotative speed (N) in rpm, of an indirect-acting reciprocating pump for cold
water is given by the equation, N = 907(L--0• 5), where L is the stroke in mm. _

• A hydraulic pump, also known as a hydraulic ram, is used to fo~ce running water to
a higher level by using kinetic energy of flow. The flow of water in the supply pipeline
is periodically stopped so that a small portion of water is lifted by the velocity head
of a larger portion. -

• The science·and technology concerning the mechanics of fluids, especially liquids,

is known as hydraulics.

• Steady flow is a flow of fluids in which all_the conditi~ns at any one point in a pipe
line are constant with respect to time.

• Triplex pumps are three-cylindered pumps used to produce overlapping deliveries

and minimize pulsation. · , - ·

• The discharge capacity of a reciprocating pump Is given by the equation, Q =11v V0 ,

where VO Is the volume displacement In m3/s, Tlv Is the volumetric efficiency, and Q

L»Nih ._.,~
t Is the discharge capacity of the pump In m3/s. _

;§§
 .,
• A d/rect-acung, S1..... - 6lr/ven re cl p~ tln g
pump Is one In which the
connects directly tovafthe
1
rl-v
liquid piston or plunger.
1te1m Pllfon
.
, . .
• In , Henry R. Worthington inv -
1840 ented the first reciprocati .
water into a boiler. ng steam pump for feedin
- g
·
-
• There are two general
types of direct-acting ste
duplex. The .simplex type am pumps: the simple
has one steam and one x and the
type has two duplicate steam an water cylin~er, while the
d two water cylinders. duplex
• A plunger-type pump
Is a reciprocating pump wh
casing Instead of on the ere the packing is on the
moving piston. stationary
.
• A diaphragm pump . .
Is a reciprocating pump
~ operating parts from pu used as a diaphragm to
mped liquid In a mechan iso lat e the ·
ically actuated diaphrag
m.
• Diaphragm pumps, an
other design of reciprocati
thick pulps, sewage sludg ng pumps, are used for
e, acids or alkaline solut handling .
solids that wear out me ions, mixture of wate'r an
tal pumps, as well as liq d gritty
constant flow volume Is uid solutions or pulps wh
required. ere a ,
·
· · • The diaphragm in
a diaphragm pump is made
abrasion, and in spe?ial of special rubber that res
cases, oil and high tempe ists corrosion,
rature. . -
• Sludge pumps are pri
marily designed for pump
to be handled successfu ing sludge or substance
lly by ce~trifugal pumps. s too heavy
. .

-
,~osLEMS .
Th8 volumetr_ic efficiency of a '96 ,c 1·2a ,c 154 mm duple~, direct-acting pump Is
1
· go%. Determine a) the commercial piston speed; and b) the pump discharge rate.
•
·'1i' A duplex,If the226·temperature
x 134 256 mm, ~team boiler fe:d p~mp is operati~g at norm?I
>c
'l3/ speed. of feed water Is 93°c and the volumetric efficiency Is
. · 99°/~. determi~e the a) ~is~on speed; b) pump discharge rate; and c) pump speed in
. · strokes per min per cyhnder. · .

3. The following are t~e test results for a 254 ,c 152 ,c 306 mm duplex, direct acting
pump:
Time of test = 1 hr
Steam used at 1.4 Mpaa, Saturated = 568 kg
Steam exhaust pressure · = . 0.1o Mpaa
• Piston speed = 38 strokes per cylinder
Water pumped = 22 700 kg
Pump TDH = 76 m
. Water temperature = 82°C
Determine the a) pump discharge rate; b) pump volumetric efficiency; c) pump
waterpower; and d~_pump duty.

4. A 110 x 210 mm single ~cting, triplex, indirect-acting pump is driven by a 1760 rpm
electric motor. The temperature of water is 110°C and the pump TOH is 230 m. If
the pump efficiency is 88%, the volumetric efficiency is 95%, and the mechanical
efficiency is 90%, specify the size of the driving motor.

• 5. Select the suitable dimensions of a duplex! direct-acting, pump for the following
· boiler servic~: • · · ·
Pump discharge = 260Ipm
Boiler pressure = 860kPaa
. Feed water temperature = 94°C · ·
Boiler water level·above pump centerline = 5.5 m
Pump dimension = D. = L ·
Volumetric efficiency . = 90%
_ Neglecting the vel~city head and pipe friction, determine the wat~r power.

Q) A 254 x 152.4 m~ duplex direct-acting pump with 38.1 mm piston rods makes 35
double strokes per_cylinder per minute and delivers 511 l_pm of 38~C against a total
head of 140 m·. The steam is supplied to the steam cylinder at a pressure of 1.2
Mpaa a_nd exhaust to the atmosphere. Amount of steam supplied is 0.5 kg/sat 98%
quallty. Assume that the piston makes a full stroke. Determine the a) piston
displacement, m3/s; b) pump slip; c) water power delivered; and d) thennal efficiency
of the pump.

dttc
 7. Determine the discharge rate, In . lps, of a 254 ,c 152.5 ,c 305 mm duplex
. operating at 35 strokes per minute if the slip ~s 7% and the water is at ee•c.
' .... . . ~ . \

• 8. Determh,e _the actual_displacement of a 152.4 x 101.6 x 254 mm simplex,.dl~

·. .· acting pump in 1pm when the inlet pressure is 1,o~.675 kPag and t~e outlet presauri
· · · 'is 13~8: 675 kPag. ·water enters _~t 110~C,_slip is 12%, and the speed is 40 str~
· per min. · - _.

a
. , 9. ·select· duplex pump for boiler feed service. Suction pressure is 83 kPaa,-waie,:
.- · temperature is 88°C. and discharge pressure is 1136.675 kPag. Assume 70%
~- ·.· · . volume_tric efficiency, 56~:81 lpm, and 64.675 kPag to 55.675 k'.a~. -. ·
1

·10. The following data were taken during the rest of a pump: 38 ·550 kg/hr; _4-inch schelfule
• 40. lnleJ pipe; 3-inch schedule 40 discharge pipe; gauge in suction line located
. 8~.36 cm below the pump centerline reads 88.9 mm Hg vacuum; discharge gauge
located 45. 72 cm below the pump centerline reads 1 206.25 kPa, water temperature
Is 49°C, Input to pump 24 Hp. Find the developed head and the pump efficie_ ncy. ·..·

·_ 11. A fire pump delivers 40000 1pm on test. The suction g~uge reads 32.4 mm Hg
vacuum and Is 21.92 cm below the pump centerline. The discharge gauge reads ··
593 kPa and is 91.44 cm above the pump centerline. What is the pump efficiency if
the water temperature is 25°C and the input is 97 Hp? .

12. A centrifugal pump receives 34 000 kg/hr of 72oC water when the pump centertine •
is 274.32 cm above the water level in a vessel that has a pressure of 31 -kPaa.
Calculate the water power, neglecting friction and velocity heads, if the discharge
pressure gauge reads 38.~ m.

II