Know and Understand Centrifugal Pumps Episode 14 ppt

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.. Example: If the pump has a 6 inch

-

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

INCORRECT

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)

Fiaure 17-18

246

Pump Piping

CORRECT DISCHARGE

PIPING

Discharge pipe diameter larger than

pump discharge

nozzle

Instrumentation

fromthelast

obstruction (valve)

upport

Reducer

Fiaure 17-19

Index

R 4 i

absolute pressure (psia), 4

Affinity Laws, The, 3 9 , 9 8 , 9 9 , 2 3 5

impeller diameter, 4 2

air aspiration, 33

alignment techniques, 145

laser alignment, 146

reverse dial indicator alignment,

rim and face alignment, 146

145

American National Standards Institute

American Petroleum Institute ( M I )

American Voluntary Standards (AVS),

Archimedes, 77

Bachus & Custodio formula, The,

bases, 148

bearing failure, 159

58

18,100

dirt and abrasion, 161

improper mounting, 160

vibration brinelling, 16 1

oil, 157

bearing maintenance, 163

bearing seals, 167

mechanical seal, 167

labyrinth seal, 168

lip seal, 169

ball bearing, 155 roller bearing, 156

Bernoulli’s Law/Principle, 3 , 2 9 , 54

brake horsepower (BHP), 40,76

203

canned motor pump, 63 cartridge concept, 214 cast iron, 2 3 3

cavitation, 25 preventing cavitation, 35 turbulence cavitation, 34 vaporization capitation, 29

chemical attack, 207 compression packing, 175 compression set, 208 corrosion, 2 3 3 corrosive liquids, 220 coupling alignment, 1 5 3 cryogenics, 220

crystallization, 2 19

dangerous liquids, 220

dial indicator, 1 4 8 , 2 2 2 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

environment controls, 2 13

equipment alignment sequence, 1 5 3

erosion, 232

ethylene propylene, 206

external flush, 21 5

extrusion, 208

failure analysis, 227

family curves, 8 5

flow, 39,46

fluid velocity, 235

fluorocarbon, 206

friction head (Hf), 9 2

calculating the Hf, 97

gases, 220

grout, 148

hard vacuum, 221

Hazen and Williams formula, The,

17,98

heat, 189

heat exchanger, 218

high pressure, 1 8 9 , 2 2 1

high speed shafts, 189

high temperature, 220

high temperature pump, 138

high velocity shaft speed, 221

hot alignment, 147

H - Q curve, see head-flow curve

impeller, 3, 48

conventional impeller, 66

impeller diameter, 4 2

pump impeller, 64

semi open impeller, 71

in-flow pipe, 239 installation dimension, 2 12 internal re-circulation, 32

magnetic drive pump, 62

back-to-back double seal, 196

cartridge, 192 double seals, 194,218 face-to-face dual seal, 197

single, outside-mounted,

single, unbalanced, inside support systems for dual seals, 198 tandem dual seal, 195

misalignment, types of, 144

negative psi, 5

net positive suction head (NPSH),

12, 5 4 , 8 2 net positive suction head available (NPSHa), 13,14

net positive suction head required (NPSHr), 1 3 , 7 6 , 8 2

nitrile, 206 non-lubricating liquids, 220 non-metallic pump, 61 O-ring, 1 8 7 , 2 1 4 O-ring (the elastomer) failure, 204 ozone attack, 209

unbalanced, 186

split, cracked o r hard, 208

packing lubricant, 178

mica 178

249

molybdenum disulfide (moly

Pascal’s Law, 4

perfluorocarbon, 206

positive displacement (PD) pump, 2,

51

pressure head (Hp), 92

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 piping, 238

pump shaft, 142

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 failure, premature, 202

shaft deflection, 128

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

Submergence Laws, 243 suction bell, 241

suction bypass, 2 15 suction head, 10 suction lift, 10

suction specific speed, Nss, 66 sweetzone, the, 140

synthetic fibers, 174 Teflon, 177

thermal jacketed seal chamber, 216 throttling, 236

total dynamic head (TDH), 92

tramp flange, 104 turbine pump, 58

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

velocity head formula, 28

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 o f several components and are ex,,,

s has been lecturing t o trifugal pumps for many

ay have read his ‘Pump Rico, has combined his knowledge

t o produce this lively and

and down t o e a consulting engineeri

understandable book

needing an accessible account of centri

ISBN: 185617 409 3

I I

I S B N 1 - 8 5 6 1 7 - 4 0 9 - 3

II I II IUI 111111 II I I1 1111