Practical Centrifugal Pumps

✍ Scribed by Paresh Girdhar B.Eng (MechEng), Octo Moniz CEng. MBA (Tech Mgt)

• Publisher: Newnes
• Year: 2005
• Tongue: English
• Leaves: 260
• Category: Library

✦ Synopsis

Practical Centrifugal Pumps is a comprehensive guide to pump construction, application, operation, maintenance and management issues. Coverage includes pump classifications, types and criteria for selection, as well as practical information on the use of pumps, such as how to read pump curves and cross reference. Throughout the book the focus is on best practice and developing the skills and knowledge required to recognise and solve pump problems in a structured and confident manner. Case studies provide real-world scenarios covering the design, set up, troubleshooting and maintenance of pumps. · A comprehensive guide to pump construction, design, installation, operation, troubleshooting and maintenance. · Develop real-world knowhow and practical skills through seven real-world case studies · Coverage includes pump classifications, types and criteria for selection, as well as practical information on the use of pumps

✦ Table of Contents

Contents......Page 6
1. Introduction......Page 10
1.1 Applications......Page 12
1.3.1 Plunger pumps......Page 13
1.3.2 Diaphragm pumps......Page 14
1.4.1 Gear pump......Page 15
1.4.2 Lobe pump......Page 16
1.4.4 Progressive cavity pump......Page 17
1.4.6 Screw pump......Page 18
1.5 Centrifugal pumps......Page 19
1.5.1 Types of centrifugal pumps......Page 21
1.5.2 Pump standards......Page 25
1.5.3 Pump applications......Page 26
2.1 Impellers......Page 27
2.1.1 Construction of impellers......Page 28
2.1.2 Impeller suction......Page 31
2.1.3 Flow outlet from impeller......Page 32
2.2 Pump casings......Page 33
2.2.2 Concentric casing......Page 34
2.2.3 Volute casing......Page 35
2.2.4 Vaned diffuser ring......Page 37
2.3 Wearing rings......Page 38
2.4 Shaft......Page 41
2.5 Stuffing boxes......Page 42
2.6 Mechanical seals and seal housings......Page 45
2.7.2 In-between bearing or fully supported shaft pumps......Page 48
2.7.4 Bearing housing protection devices......Page 49
2.8 Couplings......Page 52
2.8.2 Grid coupling......Page 53
2.8.4 Elastomeric shear type coupling......Page 54
2.8.5 Elastomeric compression type coupling......Page 55
3.2 Viscosity......Page 57
3.3 Vapor pressure......Page 58
3.6 System resistance......Page 59
3.6.1 Evaluate the suction side......Page 60
3.6.2 Evaluate the discharge side......Page 61
3.9 Pump characteristic curve......Page 62
3.9.4 Flow rate (Q) vs NPSH-r......Page 63
3.10.1 Affinity laws......Page 65
3.10.2 Viscosity corrections......Page 66
3.11 Specific speed......Page 68
3.12.2 Recirculation......Page 71
3.12.3 Net Positive Suction Head (NPSH)......Page 74
3.13 Suction-specific speed......Page 82
3.14.3 Hydraulic power......Page 83
3.14.4 Motor power......Page 84
4.1 Axial thrust......Page 85
4.1.1 Axial thrust in single-stage overhung impeller pumps......Page 86
4.1.2 Double suction impeller......Page 89
4.2 Radial loads......Page 91
4.2.1 Shaft deflection due to radial loads......Page 93
4.2.2 Calculating shaft deflection......Page 95
5. Centrifugal pump operation and characteristics......Page 98
5.1.1 Head–flow characteristics......Page 99
5.1.5 Power–flow characteristics......Page 103
5.2 Non-dimensional characteristics......Page 104
5.3 The cause of the H-Q curve......Page 105
5.4 The inlet velocity triangle......Page 106
5.5 The cause of the P-Q curve......Page 107
5.6 The effect of speed changes on characteristic curves......Page 108
5.7 The complete characteristic curve......Page 109
5.8.1 Parallel operation with similar Q-H curves......Page 111
5.8.3 Parallel operation with flat and steep Q-H curves......Page 112
5.9 Pump characteristics – viscous liquids, liquids with considerable solids......Page 114
5.10 Pump characteristics – abnormal operation......Page 115
5.11 Pump characteristics – speed–torque curve......Page 117
5.11.1 Torque from the prime mover......Page 118
5.12.1 Regulation at constant speed by throttling......Page 120
5.12.3 Regulation at constant speed by turning down the impeller......Page 121
5.12.6 Regulation by varying speed......Page 123
5.13.1 Pump operation to the left of BEP......Page 126
5.13.2 Pump operation to the right of BEP......Page 128
6. Pump specification and selection......Page 130
6.1.1 Pump boundary conditions......Page 131
6.1.2 Flow requirements......Page 135
6.1.3 Fluid specification......Page 136
6.2 Data sheet – the pump specification document......Page 137
6.3 Bid request......Page 138
6.4 Bid review/analysis......Page 139
6.5 Conclusion......Page 140
7. Pump testing and inspection......Page 141
7.1.2 Casting defects and classification......Page 142
7.1.3 Non-destructive testing (NDT)......Page 143
7.2.1 Hydrostatic test......Page 144
7.2.3 Shop acceptance criteria......Page 145
7.3 Performance test procedure......Page 146
7.3.1 NPSH testing......Page 151
8.2 Receipts and physical inspection......Page 153
8.5 Design and dimensions of pump foundation......Page 154
8.6 Excavation and forms for pump foundation......Page 155
8.7 Rebar and anchor bolts......Page 156
8.8.1 Concrete mix pour......Page 157
8.9 Base plate and sole plate preparation......Page 158
8.10.1 Epoxy grout......Page 159
8.10.2 Concrete grout......Page 160
8.12 Associated piping and fittings......Page 162
8.12.1 Inlet piping (Figure 8.6)......Page 163
8.12.2 Discharge piping (Figure 8.9)......Page 165
8.13 On-site installation and commissioning of the pump set......Page 166
8.14 Pre-operational checks......Page 167
8.16 Pump in operation......Page 168
9.1 Introduction......Page 169
9.1.1 Performance monitoring......Page 170
9.1.2 Vibration monitoring......Page 171
9.1.3 Oil and particle monitoring......Page 172
9.2 Pump breakdown and removal......Page 173
9.3 Single-stage pump dismantling and repair......Page 174
9.4.1 Impellers......Page 179
9.4.2 Pump casing......Page 180
9.4.7 Seal faces......Page 181
9.4.10 Seal housing......Page 183
9.5.1 Bearing assembly......Page 184
9.5.2 Seal assembly......Page 186
9.5.4 Seal hydrotest......Page 188
9.6 Vertical pump repair......Page 189
9.6.1 Pump dismantling and repair......Page 190
9.6.2 Preparation for assembly......Page 191
9.6.3 Pump assembly......Page 194
9.7 Multistage pump repair......Page 195
9.8......Page 199
Appendix A: Pump types......Page 204
References......Page 252
Index......Page 255