Know and Understand Centrifugal Pumps Episode 14 ppt

Know and Understand Centrifugal Pumps
-
50
-
40
-
30
-
20
-
10
-
0-
100 200
400
600 800 1000 2000
4000
6000
Figure
17-13
Figure
17-14
Use
a
‘Y’
branch and not a
‘T’
branch.
This
will
reduce turbulence.

244
Pump Piping
Slight incline
toward the
Eccentric
DRY
Straight Pipe
toward Pump
Figure
17-15
Correct suction piping leading
to
the pump (Figure
17-15).
1'1
10
DIAMETERS
.
STRAIGHT
PIPE
Figure
17-16
~ ~~~
You should respect
10
pipe diameters before the first elbow in the
suction piping (Figure
17-16).
Example: If
the

pump has
a
6
inch
suction nozzle,
you
should have
60
inches
of
straight pipe before
the
first elbow.
245
Know and Understand Centrifugal Pumps
INCORRECT
Concentric
reducer
"J
-
CORRECT
-
CORRECT
Figure
17-17
Use an eccentric pipe reducer
to
connect
to
the pump suction nozzle

(Figure
17-1
7).
Don't
use
flange bolts
to
unite misaligned piping
to
the
pump. This
damages the flange faces and
stresses
the pump casing (Figure
17-18).
INCORRECT CORRECT
Fiaure
17-18
246
Pump Piping
CORRECT DISCHARGE
PIPING
Discharge pipe
diameter larger than
pump discharge
nozzle
Instrumentation
fromthelast
obstruction (valve)
is

8
diameters pipe
upport.
Reducer
Fiaure
17-19
Index
Ri4
absolute pressure (psia),
4
Affinity Laws, The, 39,98,99,235
impeller diameter, 42
air aspiration,
33
alignment techniques, 145
laser alignment,
146
reverse dial indicator alignment,
rim and face alignment,
146
(ANSI)pump, 58,
138
145
American National Standards Institute
American Petroleum Institute (MI)
American Voluntary Standards (AVS),
Archimedes,
77
atmospheric pressure
(ATM),

4
Bachus
&
Custodio formula, The,
bases,
148
bearing failure, 159
pump,
59
58
18,100
dirt and abrasion,
161
improper mounting, 160
vibration brinelling,
16
1
grease,
158
oil,
157
bearing lubrication,
157
bearing maintenance, 163
bearing seals,
167
mechanical seal,
167
labyrinth seal,
168

lip seal,
169
bearings,
155
ball bearing, 155
roller bearing, 156
bearing temperature,
165
Bernoulli’s Law/Principle, 3,29,
54
best efficiency point
(BEP),
67,
130,
brake horsepower (BHP),
40,76
203
canned motor pump,
63
cartridge concept, 214
cast iron, 233
cavitation, 25
preventing cavitation, 35
turbulence cavitation,
34
vaporization capitation, 29
centrifugal pump,
3,54
centrifugal volute pump,
56

chemical attack, 207
compression packing, 175
compression set, 208
corrosion, 233
corrosive liquids, 220
coupling alignment, 153
cryogenics, 220
crystallization, 2
19
cutwater,
47
dangerous liquids, 220
Darcypeisbach formula, The,
17,
dial indicator, 148,222
discharge head,
10
discharge pressure,
7
drain pipe, 239
99
Index
driver shaft alignment, 142
dry running pump, 220
dual volute pump,
141
eccentric pipe reducer, 246
efficiency curve,
76,80
elastomer,

189
energy (BHp) curve,
76,81
environment controls, 2
13
equipment alignment sequence, 153
erosion, 232
ethylene propylene, 206
external flush, 21 5
extrusion, 208
failure analysis, 227
family curves, 85
flow,
39,46
fluid velocity, 235
fluorocarbon, 206
friction head
(Hf),
92
calculating the
Hf,
97
gases, 220
gauge pressure (psig),
5
grout,
148
hard vacuum, 221
Hazen and Williams formula, The,
17,98

head,
39
head-flow curve,
76,78
heat,
189
heat exchanger, 218
high pressure, 189,221
high speed shafts,
189
high temperature, 220
high temperature pump, 138
high velocity shaft speed, 221
horsepower,
44
hot alignment,
147
H-Q curve,
see
head-flow curve
impeller,
3,
48
conventional impeller,
66
impeller diameter, 42
open impeller,
70
overhung impeller,
57

pump impeller,
64
semi open impeller,
71
totally enclosed impeller,
71
turbine impeller,
65
in-flow pipe, 239
installation dimension, 2 12
internal re-circulation, 32
kinetic energy pump,
51
L/D factor,
135
lantern ring, the,
177
Laws of Similarity, The,
39
magnetic drive pump, 62
mechanical seals,
180,
184
back-to-back double seal,
196
balanced,
188
cartridge, 192
double seals, 194,218
face-to-face dual seal,

197
single, balanced, external,
187
single, balanced, internal,
186
single, outside-mounted,
single, unbalanced, inside
support systems for dual seals,
198
tandem dual seal, 195
minimum requirement curve,
76
misalignment, types of,
144
motor, the,
148
negative psi,
5
net positive suction head (NPSH),
12, 54,82
net positive suction head available
(NPSHa),
13,14
net positive suction head required
(NPSHr), 13,76,82
nitrile, 206
non-lubricating liquids, 220
non-metallic pump,
61
O-ring, 187,214

O-ring (the elastomer) failure, 204
ozone attack, 209
unbalanced,
186
mounted,
185
split, cracked or hard, 208
packing lubricant,
178
graphite,
178
mica.
178
249
Know and Understand Centrifugal Pumps
molybdenum disulfide (moly
grease),
178
Pascal’s Law,
4
perfluorocarbon, 206
pipe strain,
149
positive displacement (PD) pump, 2,
51
pressure head (Hp), 92
determining the Hp,
96
pressure measurement,
4,

6
pressure spikes, 190
properties of water,
16
pump efficiency, 50
pump head, 5
pump installation,
147
pump maintenance files, 226
pump packing, 180
pump performance curves,
76
pump piping, 238
pump shaft, 142
pump shaft packing,
171
pumping unit, 200
pumps in parallel, 120, 122
pumps in series, 120, 124
quench and drain, 217
reciprocating action, 172
regenerative turbine pump, 65
rotary action, 173
rotary turbine, 173
running alignment, 147
seal chamber pressure,
7
seal failure, premature, 202
shaft deflection, 128
shims,

149
skin formation, 220
slurries and suspended solids, 220
slurry seal, 217
soft foot, 150
solidification, 219
specific gravity,
6
specific speed,
Ns,
73
speed, 40
static head (Hs), 92
determining the
Hs,
96
stopa,
171
stuffing box,
171
Submergence Laws, 243
suction bell, 241
suction bypass, 2 15
suction head, 10
suction lift, 10
suction pressure,
7
suction specific speed,
Nss,
66

sweetzone, the, 140
synthetic fibers,
174
Teflon,
177
thermal convection tank,
198
thermal jacketed seal chamber, 216
throttling, 236
total dynamic head (TDH), 92
total head,
9
tramp flange, 104
turbine pump, 58
turbo tank,
199
turbulence, 235
vacuum, 5
vane passing syndrome, 33
vapor pressure, 24
vaporization, 220
variable elevations, 110
variable frequency drive (VFD), 39
variable resistances,
116
vegetable fibers,
171
velocity head (Hv), 92
calculating the Hv,
97

velocity head formula, 28
vertical turbine pump,
60
viscosity,
48,
157
volute type pump, 128
vortex breakers, 239
water horsepower (WHp), 45
Watt, James
44
wear bands, 72
wear
rings, 48,233
zerk (zirk) fitting, 163


ps are made up of several components and are ex,,,
s
has been lecturing to
trifugal pumps for many
ay have read his ‘Pump
Rico, has combined his knowledge
to
produce this lively and
and down to ea
consulting engineeri
understandable book
needing an accessible account of centri
ISBN:

185617
409
3
II
ISBN
1-85617-409-3
II
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II
IUI
111111
II
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I1
1111