The school system has its own definition of what

a genius is. It may not be the same definition of your genius.

ME9
FLUID MACHINERY

Different genius comes out in different environments.

Thomas Edisons genius came out in a laboratory and Steve
Jobs genius came out in his familys garage where he started
Apple computers. Mark Zuckerberg created Facebook in his
college dorm room as he created a way for his fellow students
to connect and communicate.
- Robert T. Kiyosaki

CHAPTER 1

2. Velocity head, hV - Torricellis Theorem:

Basic Energy Equations

The velocity of a liquid which discharges under a

head is equal to the velocity of a body which falls
in the same head.

1. Pressure head, hP

hv =

, v =

Where, hv = velocity head

v = velocity of fluid
g = 9.81

= 32.2

Exercise #2: Determine the velocity of the liquid in a

tank at the bottom, given that surface h = 7m.
Figure 1.1
P = f

hP, hP =

Where, P = gage pressure

hP = pressure head

= weight density
f = weight density of fluid = (S.G.)(water)
Where,

w = 9.81

Exercise #1: What

column of water?

= 62.4
is the pressure of

a 100 cm

3. Volume flow, Q

4. Power of a jet, P

Figure 1.2
Q = (A

Figure 1.3
P =

v) =

Where, A = cross-sectional area

Where, P = Power

= Weight density = g

v = velocity
Q = volume flow rate

5. For bubbles

Flow through nozzle:

Q = Cd

Where, v =
Cd = coefficient of discharge
Exercise #3: Water is flowing through a cast iron
pipe at the rate of 3500 GPM. The inside diameter of
pipe is 6 in. Find the flow velocity.

Figure 1.4

A. T = c (Isothermal) if T is not given:

P1V1 = P2V2
B. Use any process if T is given:
=
Where, P1 =

h + Patm

*absolute P

P2 = 101.325 KPa or 14.7 psi (if not given)

6.
Bernoullis
Energy
Theorem
neglecting
friction, the total head or total amount of energy
per unit weight, is the same at every point in the
path of flow.

8. Reynolds Number, NR
NR =

(dimensionless)

Where, NR < 2000 - Laminar Flow

NR > 4000 - Turbulent Flow
v = velocity of fluid
D = internal diameter of pipe
Exercise #4: Water is flowing in a pipe with radius
of 30 cm at a velocity of 5 m/s. The viscosity of
water is 1.17 Pa-s. What is the Reynolds Number?
Figure 1.5
hT = hP + h v + z
Where, z = elevation head
Using continuity flow equation:
Q1 = Q2 or A1v1 = A2v2
+

+ z1 =

+ z2

7. Viscosity,
resistance to flow
property to resist shear deformation.

or

the

A. Absolute or dynamic viscosity,

viscosity
which is determined by direct measurement of shear
resistance in

or

9. Friction head loss, hL

A. Using Morse Equation:

B.

Kinematic

Viscosity,

divided the density in

absolute

viscosity
hL =
B. Using Darcys Equation:
hL =

Where, hL = friction head loss

f = coefficient of friction or friction factor

Pitot tube - is used to measure the velocity of

flow.

L = pipe length
g = 9.81

Venturi-meter - is used to measure the volume of

flow.

Q = A1v1 = A2v2

= 32.2

C. Pressure drop in the pipe, Pd

Pd =

hL

Exercise #5: Water is flowing at a rate of 3,500 GPM.

The inside radius is 8 cm and coefficient of friction
is 0.0181. What is the pressure drop over a length of
50 m?

For circular cross-section: A =

For rectangular cross-section: A = bh

Where, =

in

A. If venturi-meter is horizontal:

Figure 1.6
=

B. If venturi-meter is vertical

Bouyancy - Archimedes Principle: A body partly or

wholly submerged in a liquid is buoyed up by a force
equal to the weight of the liquid displaced.
A. Weight of object in air

Figure 1.7
=

Figure 1.8
Wo =

- (z1 - z2)

Where, P1 = inlet pressure

P2 = throat pressure
Exercise
#6:
A
perfect
venturi
with
throat
diameter of 2 in. is placed horizontally in a pipe
with 2 inches is placed horizontally in a pipe
with 6 inches inside diameter. What is the
difference between the pipe and venturi throat
static pressure if the mass flow rate of water is
100 lb/sec?

Where,

oVo

= weight density of object = SGo

Vo = total volume of object

B. If the object is floating

Figure 1.9
BF = bouyant force = Wo =
Where, f = density of fluid = SGf
Vd = volume displaced
Ve = volume exposed to air

fVd = oVo
w

Exercise #7: A 2 meter rod floats vertically in water.

It has a 7 cm2 cross sectional and a specific gravity
of 0.6. What length, L, is submerged?

C. If the object is submerged

Figure 1.9.1
BF =

fVo

Wo =

oVo

R + BF = Wo
Where, R = weight of object in water
Vo = Vd

Exercise #8: What is the buoyant force of a body

that weighs 100 kg in air and 70 kg in water?

CHAPTER 2

Hydro-electric Power
Hydraulics - branch of mechanics which deals with the
laws governing the behavior of water and other
liquids in the states of rest and motion.
Hydrostatics - is a branch of hydraulics which deals
on the study of fluids at rest.

Lao Tzu, the Chinese founder of Taoism

in the 5th Century BC, stated:

Hydrokinetics - branch of hydraulics which deals with

the study of pure motion in liquids.

If you give a man a fish, you feed him for a day.

If you teach a man to fish you feed him for a lifetime.

Hydrodynamics - branch of hydraulics which deals with

the study of forces exerted by or upon liquids in
motion.

Are our schools failing to teach people to fish?

Or are our schools teaching students that they are
entitled to their daily fish?

Cohesion - is a fluid property which refers to the

intermolecular attraction by which the separate
particles of the fluid are held together.

Is this why there are more and more people are

dependent upon the government for life support?

Adhesion - is a fluid property which refers to the

attractive force between the molecules and any solid
substance with which they are in contact.

- RTK
Ask not what your country can do for you Ask what you can do for your country.
- President John Kennedy

Surface tension - is the force per unit length that

an imaginary film formed on the surface of a liquid
due to intermolecular attraction is capable of
exerting.
Fluid Mechanics - is a branch of science which deals
with the study of water and other fluids that are at
rest or in motion.
Reservoir - stores the water coming from the opper
river or waterfalls.
Spillway - a weir in the reservoir which discharges
excess water so that the head of the plant will be
maintained.

Dam - a concrete structure that encloses the

reservoir.
Silt sluice - a chamber which collects the mud and
through which the mud is discharged.
Trash rack - a screen which prevents the leaves,
branches and other water contaminants to enter into
the penstock.
Surge chamber - a standpipe connected to the
atmosphere and attached to the penstock so that the
water will be at atmospheric pressure.
Penstock - the channel that leads the water from the
reservoir to the turbine.
Turbine - converts the energy of the water into
mechanical energy.
Generator - converts the mechanical energy of the
turbine into electrical energy output.
Draft tube - connects the turbine outlet to the
tailwater so that the turbine can be set above the
tailwater level. Used to keep the turbine up to 15
ft. above the tail water surface.
Tailrace - a channel which leads the water from the
turbine to the tailwater.

Cavitation - occurs then the pressure at any point

in the flowing water drops below the vapor
pressure of the water which varies with
temperature.
Weir - any obstruction of a stream flow over which
water flows.
Types of turbine:
1. Propeller turbine (for small capacity) - axial
flow turbines have low heads up to 110 ft., high
rotational speeds and large flow rates. This
turbine operates with specific speeds in the range
of 80 and 200 rpm range. But best efficiencies is
between 120 and 160 rpm.
2. Reaction turbines or francis turbine (for
medium capacity) - the specific speed varies from
10 to 100. Best efficiencies are found in the 40
to 60 range. Heads between 110 to 800 ft.
3. Impulse turbine (for large capacity) - radial
flow or Pelton Wheel turbines have the lowest
specific speeds but are used when heads are high
(800 ft to 1,600 ft.). These turbines have
specific speeds below 5. The kinetic energy of the
jet is converted into rotating kinetic energy.

Tailwater - the water is discharged from the turbine.

Peripheral coefficient - ratio of the peripheral
velocity of the runner over the velocity of the jet.
Water hammer - caused because of sudden stoppage of
water flow in a pipe.
Surge tank - artificial reservoir used to relieve the
pipe line of excessive pressure.
Wicket gates - control the power and speed of turbine
Figure 2.1: Hydro-electric Power Plant

Formulas:

F. Water Power, PW

A. Gross head, hg

PW =

hg = head water elevation - tail water elevation

B. Friction head loss, hf

Where,

wQh

w = specific weight of water

= 9.81

= 62.4

Using Morse Equation:

G. Turbine efficiency, eT
hf =
eT =
Using Darcys Equation:
Where, PB = Brake power or turbine output
hf =

H. Generator efficiency, eG

Where, hf = friction head loss

f

coefficient

of

friction

eG =
or

friction
I. Turbine output, PB

factor

PB = PW

L = length of penstock
g = 9.81

= 32.2

D = inside diameter

eT

J. Generator output, Pgen

Pgen = PB

eG = (PW

eT)

eG

K. Generator speed, N

C. Net head, h

N =

h = hg - hf
D. Penstock efficiency, e
e =
E. Volume flow of water, Q
Q = Av

Where, N = speed
f = frequency
p = no. of poles (must be even no.)
L. Utilized head, hw
hw = h

eh

Where, eh = hydraulic efficiency

Exercise #1: In a hydroelectric power plant the tail

water elevation is at 500 m. What is the head water
elevation if the net head is 30 m and the head loss
is 5% of gross head?

M. Head of Pelton (Impulse) turbine:

h =

Where, = density of water = 1,000

Exercise #2: The tailwater and the headwater of a

hydro-electric plant are 150 m and 200 m
respectively. What is the water power if the flow is
15 m/s and a head loss of 10% of the gross head?

Figure 2.2: Pelton Type Turbine

Exercise #3: An impulse wheel at best produces 125
hp under a head of 210 ft. By what percent should
the speed be increased for 290 ft. head?

Exercise #4: In a double-overhung impulse-turbine

installation is to develop 20,000 hp at 275 rpm
under a net head of 1,100 ft. Determine the
specific speed.

Where, D = diameter of runner, m

N = speed of runner, rps
P. Specific speed of hydraulic turbine
NS =

, rpm

NS =

*h in feet

, rpm

*h in meters
*N in rpm

Q. Total efficiency, et
et = ehemev
Where, ev = volumetric efficiency
em = mechanical efficiency
R. Turbine type selection based on head, ft.
N. Head of Reaction (Francis and Kaplan) turbines:

NET HEAD
h =

+ z

TYPE OF TURBINE

Up to 70 feet
70 - 110 ft.

Propeller Type
Propeller or Francis

110 800 ft.

800 1,300 ft.
1,300 ft. and above

Francis Turbine
Francis or Impulse
Impulse Turbine

For small capacity, use Propeller Turbine.

For medium capacity, use Francis Turbine.
For high capacity, use Impulse Turbine.
Figure 2.3: Francis Turbine
O. Peripheral coefficient,
=

Exercise #5: A pelton type of turbine has a gross

head of 40 m and a friction head loss of 6 m. What is
the penstock diameter if the penstock length is 90 m
and the coefficient of friction head loss is 0.001
Morse?

Exercise #6: A Pelton type turbine has 25 m head

friction loss of 4.5 m. The coefficient of
friction head loss (from Morse) is 0.00093 and
penstock length of 80 m. What is the penstock
diameter?

CHAPTER 3

Air Compressor
Air Compressor - a machine which is used to increase
the pressure of a gas by decreasing its volume.

You cannot bring about prosperity by discouraging thrift.

You cannot strengthen the weak by weakening the strong.
You cannot help the wage earner by
pulling down the wage payer.
You cannot further the brotherhood of man by
encouraging class hatred.
You cannot help the poor by destroying the rich.
You cannot keep out of trouble by
spending more than you earn.
You cannot build character and courage by taking
away man's initiative and independence.
You cannot help men permanently by doing for them what
they could and should do for themselves.
- Rev. William J. H. Boetcker

The work input to a compressor is minimized when the

compression process is executed in an internally
reversible manner.
Isentropic process in compression process involves no
cooling. (n = k). For most steady-flow devices, this
is the ideal process that can be served as a suitable
model.
Polytropic process in compression process involves
some cooling. (1
n
k)
Isothermal process in compression process involves
maximum cooling. (n = 1)
Adiabatic compression requires maximum work of
compression.
Isothermal process requires minimum work of
compression.
Practically, all compressors are powered by electric
motors.
The ratio of mechanical power required to the
electrical power consumed during operation is called
the motor efficiency.
We =
Where, We = electric power/work, Wc = compressor
power/work, em = motor efficiency
Adiabatic efficiency is a measure of the deviation of
actual process from corresponding idealized zone.

Isentropic efficiency of turbine is the ratio of the

actual work output of the turbine to the work output
that would be achieved of the process between the
inlet state and the exit pressure were isentropic.

Single-stage reciprocating compressor:

eT =
Where, eT - isentropic efficiency, Wa - actual turbine
work, Wi - ideal turbine work
Isentropic efficiency of compressor is the ratio of
the work input required to raise the pressure of a
gas to a specified value in an isentropic manner to
the actual work input.
Figure 3.1
eT =
Where, eT - isentropic efficiency, Wa - actual
compressor work, Wi - ideal compressor work

Formulas:
A. Compression process 1 to 2:

Uses of compressor:
- to drive pneumatic tools
- sand blasting
- industrial cleaning
- spray painting
- starting a diesel engine
- to supply air in mine tunnels
- manufacture of plastic and industrial products
Figure 3.2

Classification of air compressor:

1. Reciprocating compressor
2. Centrifugal compressor
3. Rotary compressor

P1V1n = P2V2n

= ( )

= ( )

B. Piston displacement, VD

Where, B = D = piston rod diameter or bore

For singe-acting compressor:

VD =

S = stroke or piston length

C. Capacity of compressor, V1

B2SN,

V1 = volume flow at suction =

For double-acting compressor:

D. Volumetric efficiency, ev

ev =

= 1 + c - c(

E. Compressor power, Wc

Wc =

[( )

Where, P1 = suction pressure

Figure 3.3

P2 = discharge pressure
F. Compressor efficiency, ec
ec =
Where, PB = Brake power
G. Piston speed = 2SN
Figure 3.4
Piston rod neglected:
VD = 2(

),

Piston rod neglected:

VD = (

) + * (

+,

Exercise #1: The discharge pressure of an air

compressor is 5 times the suction pressure. If volume
flow at suction is 0.1 m/sec, what is the suction
pressure if compressor work is 19.57 KW? (Use n =
1.35).

Two-stage reciprocating compressor:

Figure 3.5
Formulas:
A. Compressor work, Wc

Wc =
Exercise #2: The initial condition of air in an air
compressor is 98 KPa and 27C and discharges air at
450 KPa. The bore and stroke are 355 mm and 381 mm,
respectively with percent clearance of 8% running at
300 rpm. Find the volume of air at suction.

[( )

B. Intercooler pressure, Px
Px =

Figure 3.6
C. Heat rejected in the intercooler, Q
Q = mcp(Tx - T1)

3. Three-stage air compressor

Where, cp = 1

m =
= ( )
Tx = intercooler temperature
D. Adiabatic compressor efficiency

Figure 3.7

ec =
E. Ideal indicated power, IP
IP = PmiVD
Exercise #3: A two stage air compressor has an
intercooler pressure of 4 kg/cm. What is the
discharge pressure if suction pressure is 1
kg/cm?
Figure 3.8
Formulas:
A. Intercooler pressure, Px
Px =
B. Compressor power, Wc

Wc =

[( )

C. Heat rejected in the intercooler, Q

Q = 2mcp(Tx - T1)
Where, cp = 1

m =

= ( )

CHAPTER 4

Fans and Blowers

The test of a first-rate intelligence is the ability to
hold two opposed ideas in the mind at the same
time, and still retain the ability to function.
F. Scott Fitzgerald
All coins have three sides: heads, tails, and the edge.
The most intelligent people live on the edge,
able to see both sides.
In school there is only one right answer.
In real life there is more than one right answer, a wave of
choices from different perspectives and points of view.
Heres an example. When I asked my poor dad what 1+1
equaled, his answer was 2. Rich dads answer to that same
question was different. His answer was 11.
This is why one man was poor and the other rich.

Fan - a machine which is used to apply power to a

gas in order to cause movement of the gas.
Blower - a fan which is used to force air under
suction, that is, the resistance to gas flow is
imposed primarily upon the discharge.
Exhauster - a fan which is used to withdraw air
under suction, that is, the resistance to gas flow
is imposed primarily upon the inlet.
Capacity of fan - volume flow rate measured at the
outlet.
Types of fans:
1. Propeller fan
2. Tubeaxial fan
3. Vaneaxial fan
4. Centrifugal fan

In other words, the idea of right vs. wrong,

which is taught in school, is unintelligent.
In fact it is ignorant, since right vs. wrong ignores,
rather than explores, the other side.
In my opinion, the idea of right versus wrong is the basis of all
disagreements, arguments, divorce, unhappiness,
aggression, violence, and war.
- RTK

Figure 4.1

D. Air power, Pa

Formulas:
A. Static head, hs

Pa =
hs =

aQh,

KW

Where, Q = fan capacity,

Where, hw = manometer reading, meters of water

E. Fan efficiency, ef

w = specific weight of water = 9.81

ef =

a = specific weight of air = 1.2

F. Static power, Ps

If both static head at suction and discharge are

given,

Ps =

aQhs

G. Static efficiency, es
hs =

es =

B. Velocity head, hv

H. Fan laws
hv =

Variable speed (constant fan size and density)

Where, vo = outlet velocity,

g = 9.81
If both
given,

velocity

suction

and

discharge

are

Q1 = Q2
Where, = density of air

hv =
C. Total head, h

P = power
h = head

h = hs + hv

= (

Variable density (constant fan size and density)

= 32.2
at

= (

N = speed

Exercise #1: A fan draws 1.42 m per second of air at

a static pressure of 2.54 cm of water through a duct
300 mm diameter and discharges it through a duct of
275 mm diameter. Determine the static fan efficiency
if total fan mechanical is 75% and air is measured at
25C and 760 mmHg.

Exercise #2: Calculate the air power of a fan that

delivers 1,200 m/min of air through a 1 m by 1.5
m oulet. Static pressure is 120 mmHg and density
of air is 1.18 kg/m3.

Exercise #3: The fan has a total head of 190 m and

a static pressure of 20 cmHg. If the air density
is 1.2 kg/m, what is the velocity of air flowing?

CHAPTER 5

Pumps
Pump - a machine which is used to add energy to a
liquid in order to transfer the liquid from one point
to another point of higher energy level.

Give, and you will receive.

Your gift will return to you in full - pressed down, shaken
together to make room for more, running over,
and poured into your lap.
The amount you give will determine the
amount you get back.
- Luke 6:38 (NLT)

Aquifers - deep ground water deposits where

underground water are available for water supply and
irrigation.
Hydraulic gradient - the locus of the elevation which
water will rise in a piezometer tube.

A mans true worth is the good he does in this world.

- Mohammad
The true principle of capitalism is,
The more people I serve, the more effective I become.
You must be generous if you want to serve as many
people as possible.
Unfortunately, many people want to be paid more,
do less, and retire early.
Doesnt this violate the principle of generosity?

Figure 5.1: Pump System

- RTK
Types of pumps:
1. Reciprocating pump
Low discharge, high head, self-priming, up to 5 ft.
suction lift, positive displacement pumps:
1. Piston type
2. Plunger type

3. Bellows or diaphragm

2. Centrifugal pump

Figure 5.3
High discharge, low head, not self-priming:
Figure 5.2
This is commonly used as Boiler Feed Pump for steam.
Reciprocating pumps can be single-acting or doubleacting.
They can be simplex, duplex, triplex, etc.
Air chamber - is to smoothen the flow due to the
nature of flow of liquid. This can be placed on the
suction side or discharge side of piping
installation.
Relief valve - this should be installed on the
discharge side between pump and any other valve.

1. Radial flow - used for single and souble

suction
2. Axial flow - acting like compressors
3. Mixed flow
Centrifugal pump is used to convert kinetic energy
into pressure energy through diffuser vanes.
Specific speed - is defined as that speed in rpm
at which a given impeller would operate to deliver
1 GPM against a total dynamic head of 1 foot.
Specific speed is constant and is given by the
manufacturer.

Foot valve - should be installed at the end of the

suction pipe.

Impellers for higher heads usually have low

specific speeds. Impellers for lower heads usually
have higher specific speeds.

All losses of capacity given in percentage of the

displacement are referred to as slip: (1 - ev).

For double suction pumps, the Q value is

determined by dividing the given capacity by 2.

In new pumps, the slippage is within 2%.

3. Rotary pump

5. Deep well pump

1. Turbine pumps - high suction lift up to 305 m.
2. Plunger pumps - are refinement of the old hand
pumps. This is best suited where the lifts are 7.6 m
or over and capacities up to 190 liters per minute.
3. Ejector - a centrifugal pump used for small
capacities combines a single-stage centrifugal pump
at the top of the well and an ejector or jet located
down in the water.
Figure 5.4

Positive
head:

displacement

pumps,

low

discharge,

low

4. Air lifts - another method of pumping wells is by

compressed air being admitted to the well to lift the
water to the surface.
Classification of pumps based on suction lift

1. vanes

1. Shallow well pump - suction lift up to 25 ft.

2. screws

2. Deep well pump - sution lift up to 120 ft.

3. lobes

3. Turbine pump - up to 300 ft.

4. gear

4. Submersible pump - for high head

5. cam and piston

Cavitation - is the spontaneous vaporization of the

fluid, resulting in a degradation of pump
performance.

6. shuttle block type

4. Kinetic pump - transform fluid kinetic energy
to fluid static ppressure energy.

Causes of cavitation:
1. Discharge head far below the pump head at peak
efficiency.

1. jet pumps
2. ejector pumps

2. High suction lift or low suction head

3. Excessive pump speed
4. High liquid temperature
Figure 5.5

Bad effects of cavitation:

Pump head:

1. Drop in capacity and efficiency

1. Friction head - head required to overcome

resistance to flow in the pipe, fittings and
valves.

2. Noise and vibration

3. Corrosion and pitting
NPSH (Net Positive Suction Head) - is the difference
between actual suction pressure and saturation vapor
pressure of the liquid.
NPSHR (Net Positive Suction Head Required) - is a
function of the pump, and will be given by the pump
manufacturer as part of the pump available at the
name plate.
NPSHA (Net Positive Suction Head Available) - is the
actual fluid energy at the inlet.
If NPSHA is less than NPSHR, the fluid will cavitate.
Preventing cavitation:
1. Increasing the height of the fluid source.
2. Reducing friction and minor losses by shortening
the suction line or using larger pipe size.
3. Reducing the temperature of the fluid at the pump
entrance.
4. Pressurizing the fluid supply tank.
5. Reducing the flow rate or velocity.

2. Velocity or dynamic head - specific kinetic

energy of the fluid.
3. Static suction head - the vertical distance
above the centerline of the pump inlet to the free
level of water source.
4. Static suction lift - the vertical distance
from pump certerline to the free level of water
source below the pump inlet.
5. Static discharge head - is the vertical
distance from pump centerline to the free level of
the fluid in the discharge tank.
6. Total suction head - is the head that includes
static head, velocity head and friction head at
the suction side.
7. Total discharge head - is the head that
includes static head, velocity head and friction
head at the discharge side.
8. Head - refers to all the head both at suction
and discharge.
9. Drawdown - is the difference between
water level and operating water level.
10. For duplex pumps:
Pump dimensions: Ds x Dw X L
Ds = steam diameter
Dw = water diameter
L = length of stroke

static

11. Pump slip

13. Parallel pump

For positive slip, the coefficient

(Cd) is less than 1 (decreases).

of

discharge

To increase
parallel.

the

discharge,

connect

the

For negative slip, the coefficient

(Cd) is more than 1 (decreases).

of

discharge

The discharge of pump in parallel is Q1 + Q2.

pump

in

The heads, h1 = h2.

12. Series pump

To increase the head, connect the pump in series.
The head of pump in series is h1 + h2.
The volume flow is Q1 = Q2.

Figure 5.7
14. To increase the head of submersible pump,
increase the number of stages of number of impeller.

Figure 5.6

Formulas:

F. Pump efficiency, ep
ep =
G. Head as determined from two pressure readings:
h =

+ z

Where, P1 is negative if vacuum

Figure 5.8
A. Volume flow rate of water, Q
Q = Av
B. Pressure head, hp
hp =
Figure 5.9
C. Velocity head, hv

H. Friction head, hf
hv =

Darcys Equation: hf =

D. Total head of pump, h

h = (hp2 - hp1) + (hv2 - hv1) + (z2 - z1) + (hf1 + hf2)
Where, z1 is negative if source is below pump center
line.

Morse Equation: hf =
I. Specific speed, Ns
Ns =

Ps is negative if it is a vacuum.
E. Water power, PW

Where, N = speed, rpm

PW =

Where,

wQh,

KW

= specific weight of water

Q = discharge, gpm
h = head, ft

J. Similar pumps:

L. Characteristics of Reciprocating pumps:

=
K. For the same pump:
Constant impeller diameter, variable speed:
Figure 5.9.1
= (

= (

1. Piston Displacement:

Constant speed, variable impeller diameter:

= (

= (

= (

Piston rod neglected:

VD = 2 (

)
Piston rod considered: VD =

Constant speed, variable fluid density:

=

),

2. Slip = VD - Q
3. %slip =

x 100%

4. volumetric efficiency, ev =

= 1 - Slip

Exercise #1: A 4 m/hr pump delivers water to a

pressure tank. At the start, the gage reads 138 KPa
until it reads 276 KPa and then the pump was shut
off. The volume of the tank is 180 liters. At 276
KPa, the water occupied 2/3 of the tank volume.
Determine the volume of water that can be taken out
until the gage reads 138 KPa.

Exercise #2: If a 1/3 horsepower pump runs for 20

min, what is the energy used?

Exercise #3: A double suction centrifugal pump

delivers 20 ft/sec of water at a head of 12 m
and running at 650 rpm. What is the specific
speed of the pump?

Generosity is the key to succes. What are our schools

teaching our children? Are they giving them fish to eat,
keeping them needy and, often, greedy? Or do they teach kids
to fish, to be self-reliant, innovative, and responsible enough
to feed themselves? Needy people become greedy people.
Greedy people become desperate people. And desperate
people do desperate things.
I believe genius is found at Maslows fifth level. At that level
are found powerful and beautiful words, values, and abilities
essential for todays world. The words are:
1. Morality: you dont have to cheat people to be rich
2. Creativity: tap into your genius
3. Spontaneity: live without the fear of making mistakes
4. Problem solving: focus on solutions
5. Lack of prejudice: having a wider context on life
6. Acceptance of fact: not afraid to face the truth
- RTK