Pumping Station Design : Revised 3rd Edition

Front Matter 1 Prefaces 3 Preface to the First Edition 3 Table of Contents 5 2. Nomenclature 13 2.1 Abbreviations 13 2.2 Definitions 20 2.3 Symbols 26 2.4 Supplementary Reading 26 3. Flow in Conduits 36 3.1 Fundamentals of Hydraulics 36 3.1.1 Continuity Equation for Mass 36 3.1.2 Energy Equation 37 3.1.2.1 Conservation of Energy 37 3.1.2.2 Energy and Hydraulic Grade Lines 38 3.1.3 Momentum Equation 38 3.2 Friction Losses in Piping 39 3.2.1 Hazen-Williams Equation and a Warning 39 3.2.2 Darcy-Weisbach Equation 40 3.2.2.1 Determination of f 40 3.2.3 Other Pipe Formulas 41 3.2.3.1 Comparison of f and C 41 3.2.4 Friction Coefficients - Warning 41 3.2.4.1 Hazen-Williams C Factor 42 3.2.4.2 Linings 42 3.2.4.3 Deposition in Pipes 43 3.2.4.4 Long Force Mains 43 3.2.4.5 Pump and Impeller Selection 43 3.3 Pipe Tables 44 3.3.1 Air in Pipelines 46 3.4 Headlosses in Pipe Fittings 46 3.5 Friction Losses in Open Channel Flow 47 3.5.1 Error in the Manning Equation 47 3.5.1.1 Quick Solutions for Manning's Equation 47 3.5.1.2 Sewers 48 3.5.2 Short Cuts 49 3.6 Energy in Pressurized Pipe Flow 49 3.7 Energy in Open Channel Flow 51 3.7.1 Theory 51 3.7.1.1 Field Determination of Critical Flow 54 3.7.1.2 Arredi Diagram 54 3.8 Unbalanced Hydraulic Forces 55 3.9 Field Measurement of Pipe Diameter and Friction Coefficient 58 3.9.1 Pressure Gauging 58 3.9.1.1 Differential Pressure 59 3.9.2 Pipe Diameter 59 3.9.2.1 Calculation of Average Pipe Diameter 59 3.9.3 Flow Rate Measurement 60 3.9.3.1 Volumetric Measurement 60 3.9.3.2 Permanent Flowmeters 60 3.9.3.3 Temporary Meters in Open Channels 61 3.9.3.4 Pump Curves 61 3.9.3.5 Temporary Flowmeters in Pipelines 61 3.9.3.6 Tracers 61 3.9.4 Calculation of Pipe Friction Coefficient 67 3.10 Flow of Sludges 67 3.11 Unsteady Flow 67 3.12 Model Studies 68 3.12.1 Model Similitude 68 3.12.2 Construction 68 3.12.3 Measurements 69 3.12.4 Acceptance Criteria 69 3.12.5 Tests 69 3.12.6 Comparison with HI Standards 70 3.13 Computational Fluid Dynamics CFD 70 3.14 References 71 4. Piping 73 4.1 Selection of Exposed Pipe 74 4.1.1 Material 74 4.1.2 Joints 75 4.1.2.1 Flanges 75 4.1.2.2 Flange Standards 77 4.1.2.3 Facings 77 4.1.2.4 Pressure Ratings 78 4.1.3 Gaskets 79 4.1.4 Thickness 79 4.1.5 Linings and Coatings 80 4.1.6 Fittings 81 4.1.7 Expansion, Contraction, and Vibration 81 4.1.8 Summary: Pumping Station Piping 82 4.2 Selection of Buried Piping 83 4.2.1 Material 83 4.2.2 Practical Selection 83 4.2.3 Joints 84 4.2.4 Gaskets 84 4.2.5 Thickness 84 4.2.6 Linings, Coatings, and Cathodic Protection 84 4.2.7 Fittings 88 4.2.8 Economics 88 4.3 Ductile Iron Pipe DIP 89 4.3.1 Materials 89 4.3.2 Available Sizes and Thicknesses 89 4.3.3 Joints 90 4.3.4 Gaskets 90 4.3.5 Flange Interfaces with Certain Flanged Valves 90 4.3.6 Fittings 90 4.3.7 Linings and Coatings 90 4.4 Steel Pipe 91 4.4.1 Material 91 4.4.2 Available Sizes and Thicknesses 91 4.4.3 Joints 92 4.4.4 Fittings 92 4.4.5 Gaskets 93 4.4.6 Flange Interfaces with Certain Flanged Valves 93 4.4.7 Linings and Coatings 93 4.5 Plastic Pipe 93 4.5.1 Available Sizes and Thicknesses 94 4.5.2 Joints 95 4.5.3 Gaskets 95 4.5.4 Valve Pressure Rating 95 4.5.5 Fittings 95 4.5.6 Criteria for Selection of PVC Pressure Pipe 95 4.6 Asbestos Cement Pipe ACP 96 4.6.1 Available Sizes and Thicknesses 96 4.6.2 Joints and Fittings 96 4.7 Reinforced Concrete Pressure Pipe RCPP 96 4.7.1 Sizes and Joints 97 4.7.2 Wall Thickness Design 97 4.7.3 Fittings 97 4.7.4 Linings 97 4.8 Design of Piping 97 4.8.1 Exposed Piping 98 4.8.1.1 Tie Rods 98 4.8.1.2 Bending 98 4.8.1.3 Pipe Wall Thickness 100 4.8.1.4 Hangers and Supports 100 4.8.2 Buried Piping 103 4.8.2.1 External Loads 103 4.8.2.2 Thrust Blocks 104 4.8.3 Cleanouts 106 4.8.4 Pig Launching and Recovery 106 4.9 Special Piping and Plumbing 107 4.9.1 Water 107 4.9.2 Threaded Joints 109 4.9.3 Van Stone Flanges 109 4.9.4 Diesel Fuel Service 109 4.9.5 Sewers 111 4.9.6 Dry Chlorine Gas 111 4.9.7 Chlorine Solutions 111 4.9.8 Air 111 4.9.9 Design of Plumbing Systems 111 4.9.10 Storm Drainage 111 4.9.11 Sanitary Drainage 112 4.9.12 Cross Connections 112 4.9.13 Sumps 112 4.10 References 112 5. Valves 114 5.1 Designing for Quality 114 5.1.1 Life-Cycle Cost 116 5.1.2 Location 116 5.1.3 Check Valves 117 5.1.4 Safety 117 5.1.5 Flange Interfaces with Piping 117 5.2 Isolation Valves 117 5.2.1 Isolation Valves for Water Service 117 5.2.2 Isolation Valves for Wastewater Service 118 5.2.3 Description of Isolation Valves 118 5.2.3.1 Ball Valves 118 5.2.3.2 Butterfly Valves 121 5.2.3.3 Cone Valves 122 5.2.3.4 Diaphragm Valves Not Stem Guided 122 5.2.3.5 Eccentric Plug Valves 122 5.2.3.6 Gate Valves 124 5.2.3.7 Double Disc Gate Valves 125 5.2.3.8 Solid Wedge Gate Valves 125 5.2.3.9 Resilient Seated Gate Valves 125 5.2.3.10 Knife Gate Valves 125 5.2.3.11 Pinch Valves 126 5.2.3.12 Plug Valves Lubricated and Nonlubricated 126 5.3 Sluice Gates, Shear Gates, Flap Valves, and Stop Plates 127 5.3.1 Sluice Gate 127 5.3.2 Shear Gates 127 5.3.3 Flap Valves 128 5.3.4 Stop Plates 128 5.4 Check Valves 128 5.4.1 Valve Slam 129 5.4.2 Preventing Valve Slam 130 5.4.2.1 Small Valves 130 5.4.2.2 Spring-Loaded Levers 130 5.4.2.3 Counterweight and Dashpot 130 5.4.2.4 Pressure-Regulated Bypass Dump 130 5.4.2.5 Actuator-Controlled Plug or Ball Valve 130 5.4.2.6 Summary 130 5.4.3 Check Valves for Water Service 131 5.4.4 Check Valves for Wastewater Service 131 5.4.5 Description of Check Valves 131 5.4.5.1 Ball Lift Check Valves 131 5.4.5.2 Center-Post Guided Check Valves 132 5.4.5.3 Double Leaf Check Valves 132 5.4.5.4 Foot Valves 132 5.4.5.5 Lift Check Valves 133 5.4.5.6 Swing Check Valves 133 5.4.5.7 Cushioned Swing Check Valves 133 5.4.5.8 Rubber Flapper Check Valves 134 5.4.5.9 Slanting Disc Check Valves 134 5.5 Control Valves 134 5.5.1 Pump-Control Valves 135 5.5.2 Control Valves for Water Service 135 5.5.3 Control Valves for Wastewater 135 5.5.4 Description of Control Valves 135 5.5.4.1 Angle Valves 135 5.5.4.2 Globe Valves 136 5.5.4.3 Globe or Piston Valves with Vee-Ports 136 5.5.4.4 Needle Valves 137 5.5.5 Special Control Valve Functions 137 5.5.5.1 Altitude Control Valves 137 5.5.5.2 Pressure Relief Valves 137 5.5.5.3 Surge Anticipation Valves 137 5.6 Valve Actuators 137 5.6.1 Manual Actuators 137 5.6.2 Powered Actuators 139 5.6.2.1 Electric Actuators 139 5.6.2.2 Hydraulic Actuators 139 5.6.2.3 Pneumatic Actuators 140 5.7 Air and Vacuum Valves 140 5.7.1 Air and Vacuum Valves in Water Service 141 5.7.2 Air and Vacuum Valves in Wastewater Service 141 5.8 Materials of Construction 142 5.8.1 Bodies 142 5.8.2 Seats 142 5.8.2.1 General 142 5.8.2.2 Teflon^TM 142 5.8.2.3 Elastomers 143 5.8.3 Packing 143 5.8.4 Stems 143 5.9 Installation of Valves 143 5.9.1 End Connections 143 5.10 Corrosion Protection 144 5.11 References 144 6. Fundamentals of Hydraulic Transients 146 6.1 Introduction 146 6.2 Nomenclature 147 6.3 Methods of Analysis 147 6.4 Surge Concepts in Frictionless Flow 148 6.4.1 Pressure Head Change 150 6.4.1.1 Elastic Wave Speed 151 6.5 Slow Closure of Valves 152 6.6 Surge Concepts in Flow with Friction 155 6.7 Column Separation 156 6.8 Criteria for Conducting Transient Analysis 157 6.9 References 158 7. Control of Hydraulic Transients 159 7.1 Overview of Hydraulic Transient Control Strategies 159 7.1.1 Recommended Options for Wastewater Systems 160 7.1.2 Options Undesirable for Wastewater Systems 162 7.1.3 Recommended Options for Water Systems 162 7.1.4 Power Failure 162 7.1.5 Column Separation 163 7.1.6 Start-up 163 7.1.7 Shut-Down 164 7.1.8 Check Valve Slam 165 7.1.9 Choosing Check Valves 166 7.1.10 Filling Empty Pipelines 166 7.2 Control of Pumps 166 7.2.1 Pump Sequencing 167 7.2.2 Pump-Control Valves 167 7.2.3 Increasing the Rotational Inertia 167 7.2.4 Variable-Speed Drives 167 7.3 Control Tanks 167 7.3.1 Standpipes 168 7.3.2 One-Way Surge Tanks 168 7.3.3 Two-Way Surge Tanks 168 7.3.4 Air Chambers 168 7.4 Valves for Transient Control 169 7.4.1 Air and Vacuum Control 169 7.4.1.1 Vacuum Relief Valves 169 7.4.1.2 Air Release Valves 169 7.4.1.3 Air Release and Vacuum Relief Valves in Water Mains 169 7.4.1.4 Air Release and Vacuum Relief Valve in Wastewater Force Mains 170 7.4.2 Check Valves 170 7.4.2.1 Swing Check Valves 170 7.4.2.2 Cushioned Check Valves 170 7.4.3 Surge Relief Valves 170 7.4.4 Surge Anticipation Valves 170 7.5 Containment of Transients 171 7.6 Surge Control for Water Pumping Stations 173 7.6.1 Deep Well Pump 173 7.6.2 Low Suction-Lift Turbine Pump 176 7.6.3 Air Chamber with Turbine Pump 176 7.6.4 Turbine Booster Pump 176 7.6.5 Centrifugal High Service or Booster Pump 176 7.7 Surge Control for Raw Wastewater Pumping Stations 176 7.7.1 Quick-Closing Check Valve 176 7.7.2 Pump-Control Valve 176 7.7.3 Increasing Rotational Inertia 177 7.7.4 Other Control Strategies 177 7.8 Pipeline Design 177 7.8.1 Upsurge 177 7.8.2 Downsurge 178 7.9 Computer Analysis 179 7.10 Transients in Distribution Systems 181 7.11 References 184 8. Electrical Fundamentals and Power System Principles 185 8.1 Definitions and Code References 185 8.2 Electrical Fundamentals 186 8.2.1 Generation of Electricity 187 8.2.2 Inductance 188 8.2.3 Capacitance 188 8.2.4 Power 189 8.2.4.1 Direct Current Power 189 8.2.4.2 Alternating Current Power 189 8.2.4.3 Three-Phase Power 190 8.2.5 Electrical Measurements 192 8.2.6 Basic Electrical Calculations 193 8.3 Power and Control System Elements 193 8.3.1 Solenoids 193 8.3.2 Relays 194 8.3.3 Timing Relays 194 8.3.4 Programmable Logic Controllers 194 8.3.5 Transformers 194 8.3.6 Switches 196 8.3.7 Fuses 197 8.3.8 Circuit Breakers 197 8.3.9 Motor Branch Circuits and Controllers 200 8.3.9.1 Controllers for AC Squirrel-Cage Motors 200 8.3.9.2 Across-the-Line Starters 201 8.3.9.3 Reduced-Voltage Starters 202 8.3.9.4 Autotransformer Type 203 8.3.9.5 Primary Resistor Type 203 8.3.9.6 Wye-Delta Type 203 8.3.9.7 Part Winding Type 203 8.3.9.8 Solid-State Type 203 8.3.10 Motor Control Circuits and Devices 204 8.3.11 Motor Control Centers 205 8.3.12 Insulated Cables and Conductors 206 8.3.12.1 Cables 206 8.3.12.2 Conductors and Terminations 206 8.3.12.3 Insulation 208 8.3.12.4 Current Rating 208 8.3.13 Raceways and Wireways 208 8.3.14 Junction and Outlet Boxes 209 8.3.15 Switchgear and Switchboards 209 8.3.16 Service Entrances 210 8.3.17 Equipment Installation 210 8.4 Standby Generators and Auxiliaries 210 8.4.1 Codes and Legal Requirements 211 8.4.2 Ratings 211 8.4.2.1 Continuous Rating 211 8.4.2.2 Motor-Starting Rating 211 8.4.2.3 Fault Rating 211 8.4.2.4 Derating 211 8.4.3 Engine-Generator Controls 211 8.4.4 Automatic Transfer Controls 212 8.4.4.1 Code Requirements 212 8.4.4.2 Manual Transfer Switches 212 8.4.4.3 Automatic Transfer Switches 212 8.4.5 Batteries 213 8.4.6 Battery Chargers 213 8.5 Grounding 213 8.5.1 System Grounding 213 8.5.2 Equipment Grounding 213 8.5.3 Ground Fault Protection 215 8.5.3.1 System Protection 215 8.5.3.2 Ground Fault Circuit Interrupter 215 8.5.4 Surge and Lightning Protection 215 8.5.4.1 Lightning Protection 216 8.6 Lighting and Power Outlets 216 8.6.1 Interior Lighting Equipment Selection 216 8.6.2 Energy Conservation 217 8.6.3 Fixture Location 217 8.6.4 Switching 217 8.6.5 Exterior Lighting 218 8.6.5.1 Entry or Security Lights 218 8.6.5.2 Roadway and Parking Lots 218 8.6.6 Emergency Lighting 218 8.6.6.1 Codes and Legal Requirements 218 8.6.6.2 Self-Contained Lighting Units 218 8.6.6.3 Exit Signs 218 8.6.6.4 Transfer Controls 218 8.6.7 Convenience Outlets 219 8.6.7.1 Low Voltage 219 8.6.7.2 Special Outlets 219 8.7 Electrical Circuit Diagrams 219 8.7.1 Single-Line Diagrams 219 8.7.2 Control Diagrams 221 8.7.3 Coordination 221 8.8 Power and Control System Practices 221 8.8.1 Voltage Terminology 221 8.8.2 Standard Nominal System Voltages 222 8.8.3 Station Voltage Selection 223 8.8.3.1 Voltage Ratings for Utilization Equipment 223 8.8.4 Load Estimating 223 8.9 Reference 225 9. Electrical Design 226 9.1 Final Construction Drawings 226 9.1.1 List of Electrical Drawings 227 9.1.2 Symbols 227 9.1.3 Coordination with other Pumping Station Drawings 227 9.1.4 Raceway System 227 9.1.5 Wiring 228 9.1.6 Equipment Space Heaters 228 9.1.7 Power and Telephone Utility Requirements 228 9.2 Specifications 228 9.2.1 Coordination with other Specification Sections 229 9.2.2 Seismic Requirements 229 9.2.3 Equipment Labeling 229 9.2.4 Shop Drawings 229 9.3 Contacting Utilities 229 9.3.1 Electric Power Utility Contact 229 9.3.2 Telephone Company Contact 230 9.4 Construction Information to Utilities 230 9.5 Load Estimation 230 9.6 Overcurrent Protection and Conductor Sizing 233 9.6.1 Fuses 233 9.6.2 Circuit Breakers 234 9.6.3 Checking Branch Circuit Voltage Drop 235 9.6.4 Miscellaneous Drives and Loads 235 9.6.5 Service Load 238 9.7 Lighting 239 9.7.1 Correction of Power Factor 241 9.8 Power Factor 241 9.8.1 Correction of Power Factor 241 9.8.1.1 Capacitors 242 9.8.1.2 Conductors 242 9.9 Engine Generators 242 9.9.1 Need for Engine Generators 243 9.9.2 Engine-Generator Sizing 243 9.10 Short-Circuit Current Calculations 246 9.10.1 Fault Short-Circuit Current Magnitude 246 9.10.2 Coordination 247 9.11 Harmonics 247 9.12 Construction Service 247 9.12.1 Shop Drawing Review 247 9.12.2 Submittal Checklist 247 9.12.3 Inspection 247 9.12.4 Tests 248 9.12.4.1 Factory Tests 248 9.12.4.2 Field Tests 248 9.13 References 248 10. Performance of Centrifugal Pumps 250 10.1 Classification of Centrifugal Pumps 250 10.2 Pump Application Terminology, Equations, and Performance Curves 250 10.2.1 Capacity 251 10.2.2 Head 251 10.2.3 Power 254 10.2.3.1 Output Power 254 10.2.3.2 Input Power 254 10.2.4 Pump Performance Curves 257 10.3 Pump Operating Characteristics 257 10.3.1 Energy Transfer in Radial Centrifugal Pumps 257 10.3.2 Flow, Head, and Power Coefficients 258 10.3.3 Affinity Laws 259 10.3.4 Approximate Relationships for Radial-Flow Pumps 262 10.3.5 Specific Speed 263 10.4 Cavitation 265 10.4.1 Occurrence of Cavitation and its Effects 266 10.4.1.1 Performance Degradation and NPSH 266 10.4.1.2 Cavitation Damage 268 10.4.1.3 Erosive Damage and Suction Energy 268 10.4.1.4 Energy Level, TDH, and Cavitation Erosion Rate 268 10.4.1.5 Off-Design Operation 268 10.4.1.6 Minimum Flow Limits 269 10.4.2 Domains and Operational Criteria for NPSH 269 10.4.3 Difference between Cavitation Inception and Incipient Head Reduction 269 10.4.3.1 Net Positive Suction Head Required 269 10.4.3.2 Potential for Cavitation Damage 270 10.4.3.3 Domains versus Flow Rate Discharge 270 10.4.3.4 Air Injection 271 10.4.3.5 Taking Precautions 271 10.4.4 Determining the Available Net Positive Suction Head, NPSHA 271 10.4.5 Calculating the Required Net Positive Suction Head, NPSHR 272 10.4.6 Predicting NPSHR at Off-BEP Flow Rates 273 10.4.7 Prevention and Control of Cavitation 274 10.4.7.1 Raising NPSHA 275 10.4.7.2 Reducing the NPSHR 275 10.4.7.3 Changing the Pump Design 276 10.5 Pump Characteristic Curves 276 10.5.1 Nondimensional Pump Characteristic Curves 276 10.5.2 Stable and Unstable Pump Curves 277 10.6 Pump Operating Regions 279 10.6.1 Radial Thrust 280 10.6.2 Cavitation 281 10.6.3 Fixed Efficiency Loss 281 10.6.4 Pump Operating Range 281 10.7 Elementary Pump System Analysis 281 10.7.1 System Head-Flow Rate H-Q Curves 281 10.7.1.1 Single-Pump, Single-Speed Operation 283 10.7.1.2 Single-Pump, Variable-Speed Operation 284 10.7.2 Multiple Pump Operation 285 10.7.2.1 Parallel Operation 285 10.7.2.2 Series Operation 286 10.8 Practical Pumping System H-Q Curve Analysis 286 10.8.1 Constant-Speed C/S Pumps in Parallel 287 10.8.2 Station Curves 287 10.8.3 Analysis 288 10.8.4 Specifications for Purchase Orders 289 10.8.5 Hydraulic Profile 289 10.8.6 Variable-Speed V/S Pumps in Parallel 290 10.8.6.1 Full-Speed Operation 290 10.8.6.2 Low-Speed Operation 290 10.8.6.3 All Pump Speeds 291 10.8.7 Communicating with Manufacturers 291 10.8.8 Deep Wet Wells 292 10.8.9 Computer Modeling 292 10.9 Complex Pumping System H-Q Curves 292 10.10 References 292 11. Types of Pumps 294 11.1 General Classifications of Pumps 294 11.1.1 Kinetic Pumps 294 11.1.1.1 Centrifugal Pumps 296 11.1.1.2 Vertical Pumps 296 11.1.2 Positive Displacement Pumps 296 11.1.2.1 Reciprocating Pumps 296 11.1.2.2 Rotary Pumps 296 11.1.2.3 Pneumatic Pump 299 11.2 Classification of Centrifugal Pumps 299 11.2.1 Overhung-Impeller Pumps 299 11.2.1.1 Separately Coupled Pumps 299 11.2.1.2 Close-Coupled Pumps 300 11.2.1.3 Submersible Pumps 300 11.2.2 Impeller-between-Bearings Pumps 300 11.2.2.1 Axial-Split-Case Pumps 300 11.3 Construction of Centrifugal Pumps 300 11.3.1 Impeller 301 11.3.1.1 Wear Rings 303 11.3.1.2 Wear Plates 304 11.3.2 Pump Shaft 304 11.3.2.1 Shaft Sleeve 305 11.3.2.2 Pump Casing 306 11.3.2.3 Suction Cover 306 11.3.2.4 Stuffing Box Cover 306 11.3.3 Frame and Bearing Housings 306 11.3.4 Bearings 306 11.3.5 Bearing Seals 307 11.3.5.1 Close-Clearance Seals 307 11.3.5.2 Elastomer Seals 307 11.3.5.3 Labyrinth Seals 307 11.3.6 Pump Shaft Seals 307 11.3.6.1 Packing 307 11.3.6.2 Mechanical Seals 308 11.3.6.3 SpiralTrac^TM Seals 308 11.3.7 Separately Coupled Pump Design 308 11.3.8 Close-Coupled Pump Design 308 11.3.9 Submersible, Close-Coupled Pump Design 308 12. Pumps: Intake Design, Selection, and Installation 310 12.1 Design of Pump Intakes 311 12.2 Pump Intake Design Standards 311 12.2.1 Pump Inlet Conditions 312 12.3 Types of Pump Intake Basins 313 12.3.1 Unconfined 313 12.3.1.1 Design 313 12.3.2 Rectangular 313 12.3.2.1 Design 313 12.3.3 Trench-Type 314 12.3.3.1 Design 315 12.3.4 Circular 315 12.3.4.1 Design 315 12.3.5 Cans or Barrels 316 12.3.5.1 Design 316 12.3.6 Submerged Barrel Intakes 317 12.3.6.1 Design 317 12.3.7 Confined 317 12.3.7.1 Design 317 12.3.8 Formed Suction Intakes FSIs for Large Pumping Stations 317 12.3.8.1 U.S. Army Type 10 FSIs 317 12.3.8.2 Compact FSI 318 12.3.8.3 Swan Island Pumping Station FSI 318 12.3.8.4 FSIs: Conclusions 319 12.3.8.5 Corrosion 319 12.3.8.6 Design and Installation 320 12.3.9 Manifold or Header 320 12.3.9.1 Design 320 12.3.10 Suction Tank 320 12.3.10.1 Design 320 12.4 Model Study 320 12.4.1 Need for Model Study 320 12.5 Evolution of Trench-Type Wet Wells 321 12.5.1 Original Wet Wells 321 12.5.2 Tests with Sand 322 12.5.3 Development of Improved Trench-Type Wet Wells 322 12.5.4 Improvements. Normal Operation 325 12.5.4.1 Uneven Distribution of Throat Velocities in Pump Inlets 325 12.5.4.2 Surface Vortices 326 12.5.4.3 Underwater Vortices 327 12.5.4.4 Dry Pit Pump Intakes 328 12.5.4.5 Swirling 329 12.5.5 Improvements. Cleaning Operations 330 12.5.5.1 Entrance Conditions 330 12.5.5.2 Trench 331 12.5.5.3 Circulation behind Last Pump 331 12.5.5.4 Elevation of Last Pump 331 12.5.6 Fabricating Improvement Devices and Facilities 332 12.5.6.1 Ramps 332 12.5.6.2 Support of Wall and Sloping Floor Shoulder above Trench 332 12.5.6.3 Flow Splitters 332 12.5.6.4 Fillets 334 12.5.6.5 Flow Splitters and Fillets for Laboratory Models 334 12.5.6.6 Entrance Baffle 334 12.5.6.7 Cones and Vanes 334 12.5.6.8 Anchorage 334 12.5.7 Alternatives 334 12.5.8 Submersible Pumps 334 12.5.9 Other Pumps 335 12.5.10 Choice of Drivers 335 12.5.10.1 Combining C/S and V/S Pumps 335 12.6 Summary of Trench-Type Wet Well Characteristics 335 12.6.1 Sumps for Solids-Bearing Waters 335 12.6.2 Controls for V/S Pumping 337 12.7 Trench-Type Wet Well Design 337 12.7.1 Wet Wells for V/S Pumps 337 13. Electric Motors 341 13.1 General 341 13.1.1 Definitions 342 13.1.2 Standards and Codes 343 13.2 Applications of Motors 343 13.2.1 Motor Nameplate 344 13.2.2 Ambient Conditions 345 13.2.3 Mountings 345 13.3 Fundamentals 346 13.3.1 Squirrel-Cage Induction Motors 346 13.3.2 Wound-Rotor Motors 347 13.3.3 Synchronous Motors 348 13.4 Types of Motors for Pump Drivers 349 13.4.1 Squirrel-Cage Induction Motors 349 13.4.1.1 Efficiency 350 13.4.2 Wound-Rotor Induction Motors 350 13.4.3 Synchronous Motors 351 13.4.4 Multispeed Motors 351 13.4.5 Constant- and Adjustable-Speed Systems 351 13.5 Characteristics of Squirrel-Cage Induction Motors 352 13.6 Motor Speed 352 13.7 Motor Voltage 353 13.8 Enclosures 354 13.9 Insulation 355 13.10 Squirrel-Cage Motors 356 13.10.1 Service Factors 356 13.10.2 Insulation and Service Factor 356 13.10.3 Ambient Conditions 356 13.10.4 Responsibility 356 13.10.5 Critique of Example 13-1 360 13.11 Frequency of Motor Starts 360 13.12 Miscellaneous Motor Features 361 13.12.1 Shafts 361 13.12.2 Bearings 361 13.12.3 Space Heaters and Winding Heating 362 13.12.4 Temperature Sensors 362 13.12.5 Vibration Monitors 362 13.12.6 Moisture Sensors for Submersible Motors 363 13.13 Specifying Pumping Unit Drivers 363 13.13.1 Motors for Water Pumping 363 13.13.2 Motors for Wastewater Pumping 364 13.14 Definite Purpose Induction Motors 364 13.14.1 Inverter-Duty Motors 364 13.14.1.1 Design 365 13.14.1.2 Operating Standard Motors with AF Inverters 365 13.14.1.3 Alternative Preventive Measures 365 13.14.1.4 Other Considerations for AFD Installations 367 13.14.2 Immersible Motors 367 13.14.2.1 Design 367 13.14.2.2 Protection 367 13.15 Design Checklist 368 13.16 References 369 14. Engines 370 14.1 Selecting an Engine Drive 370 14.2 Duty Cycle 371 14.2.1 Direct Drive 371 14.2.2 Electric Generator Duty 372 14.2.3 Continuous Duty 372 14.2.4 Standby Duty and Standby Generators 372 14.3 Fuel for Engines 373 14.3.1 Natural Gas 373 14.3.2 Propane 374 14.3.3 Butane 374 14.3.4 Biogas 374 14.3.5 Diesel Fuel 375 14.3.6 Gasoline 376 14.4 Aspiration 376 14.5 Types of Engines 376 14.5.1 Ignition 376 14.5.2 Cycle 376 14.5.3 Configuration 376 14.6 Rich-Burn or Lean-Burn 377 14.7 Application Criteria 377 14.7.1 Brake Mean Effective Pressure 377 14.7.2 Derating for Altitude 378 14.7.3 Piston Speed 379 14.7.4 Rotative Speed 379 14.7.5 Other Criteria 379 14.8 Starting Methods 379 14.9 Cooling Methods 379 14.10 Controls 379 14.11 Governors for Engine Control 380 14.12 Accessories for Engines 381 14.13 Combustion Air 384 14.14 Exhaust Silencing 384 14.15 Pollution Control 386 14.16 Vibration Isolation 386 14.17 Lubrication Oil Storage and Supply 386 14.18 Fuel Oil Storage and Supply 387 14.19 Gaseous Fuel Storage and Supply 387 14.20 Service Piping 388 14.21 Building Envelope 388 14.22 Ventilation 389 14.23 Maintenance 389 14.23.1 Prime Movers 389 14.23.2 Standby Engines 389 14.23.3 Exercising Engines 389 14.23.3.1 Continuous-Duty Engines 389 14.23.3.2 Standby Service 389 14.23.3.3 Manufacturers' Recommendations 390 14.23.4 Batteries 391 14.23.5 Heaters 391 15. Variable-Speed Pumping 392 15.1 Variable Speed versus Constant Speed 393 15.1.1 Advantages of Variable-Speed Pumping 393 15.1.1.1 Wastewater 393 15.1.1.2 Water 394 15.1.2 Disadvantages of Variable-Speed Pumping 394 15.1.3 Summary 395 15.2 Design Considerations 395 15.2.1 Pumps 395 15.2.2 Wet Wells 395 15.3 Theory of Variable-Speed Pumping 395 15.3.1 Speed versus Flow Curves 395 15.3.2 Affinity Law for Speed 395 15.3.3 Minimum Operating Speed 397 15.3.4 Pump Efficiencies 398 15.3.5 Power Required 399 15.4 Pump Selection 400 15.4.1 Two-Pump Facility 400 15.4.2 Three Variable-Speed Pumps 400 15.4.2.1 Load-Sharing Operation 401 15.4.2.2 Comparison of Operating Modes 402 15.4.3 Selections for Steep System Curves 403 15.4.4 Four Variable-Speed Pumps 403 15.5 Variable- and Constant-Speed Pumps in Simultaneous Operation 403 15.6 Special Design Considerations 404 15.6.1 Maximum Speed Limit 404 15.6.2 Control of Pumping Units 405 15.6.3 Pump Failure Detection 405 15.6.4 Power-Operated Check Valves 405 15.7 Analysis of Variable-Speed Booster Pumping 406 15.7.1 Pump Characteristic Curves 406 15.7.2 Required Differential Head Curves 406 15.7.3 Suction Pressure Varies with Flow Rate 407 15.7.4 Suction Pressure Constant 408 15.7.5 Suction Pressure Varies Independently of Flow Rate 408 15.7.6 Suction Pressure Varies Both Independently and Dependently with Flow Rate 410 15.8 Minimum Flow Rate 410 15.8.1 Suction Pressure Varies with Flow Rate 412 15.8.1.1 Flowmeter and Bypass 412 15.8.1.2 Small Pumps 413 15.8.1.3 Hydropneumatic Tank 413 15.9 Operations in Booster Pumping 413 15.9.1 Sequencing 413 15.9.1.1 Starting Lag Pumps 413 15.9.1.2 Stopping Lag Pumps 414 15.10 Simultaneous Operation of V/S and C/S Booster Pumps 415 15.10.1 Pumping Unit Failure Detection 415 15.10.2 Other Considerations 416 15.11 Adjustable- and Variable-Speed Drives 416 15.11.1 Direct Engine Drives 416 15.11.1.1 Engine-Generator Drives 416 15.11.1.2 Combination Drives 420 15.11.1.3 Peak Shaving 421 15.11.2 Adjustable-Frequency Drives 421 15.11.2.1 Harmonics 422 15.11.2.2 Efficiency 423 15.11.2.3 Operating Costs 423 15.11.2.4 Motors 424 15.11.2.5 Inverter-Duty Motors 424 15.11.2.6 Converters 425 15.11.2.7 Operational Problems 425 15.11.2.8 Adjustable-Frequency Drive Specifications 425 15.11.2.9 Standby Generators 427 15.11.2.10 Maintenance 427 15.11.2.11 Summary 428 15.11.3 Electromagnetic Eddy-Current Couplings 428 15.11.3.1 Efficiency 428 15.11.3.2 Stationary Field Eddy-Current Couplings 430 15.11.4 Permanent-Magnet Eddy-Current Couplings 430 15.11.5 Rheostat-Controlled Wound-Rotor Drives 430 15.11.6 Fluid Couplings Hydrokinetic 431 15.11.7 Slip-Recovery Drives 431 15.11.8 Variable-Ratio Belt Drives 432 15.11.9 Hydrostatic Drives 432 15.11.10 Other Drives 432 15.12 References 432 16. Pump-Driver Specifications 433 16.1 Comparison of Two Approaches to Writing Specifications 433 16.2 Methods for Specifying Quality of Equipment 434 16.3 Nonrestrictive Specifications 434 16.3.1 Research Needs 435 16.3.2 Effect of Size and Complexity 435 16.4 Operating Conditions 436 16.5 Mass Elastic Systems and Critical Speeds 436 16.6 Pump Testing 436 16.6.1 Test Requirements 437 16.6.2 Factory Pump Tests 437 16.6.3 Witnessed Pump Tests 437 16.6.4 Variable-Speed Pumps 438 16.6.5 Example Specifications 439 16.6.6 Field Pump Tests 439 16.6.6.1 Field Operational Tests 439 16.6.6.2 Field Pump Acceptance Tests 440 16.7 Shipping Major Pumping Units 440 16.8 Submittals 440 16.9 Product Data 441 16.10 Seals 441 16.11 Pump Shafts 441 16.12 Pump Shaft Bearings 441 16.13 Vertical Drive Shafts 441 16.14 Electric Motors 441 16.15 Optimum Efficiency 442 16.16 References 442 17. System Design for Wastewater Pumping 443 17.1 Organization and Control of the Process 443 17.2 Preliminary Engineering 444 17.2.1 Need for Pumping Stations 444 17.2.2 Site Selection 444 17.2.2.1 Subsurface Conditions 444 17.2.2.2 Aesthetic Considerations 445 17.2.2.3 Force Main Route 445 17.2.3 Required Capacity 445 17.2.4 Wastewater Characteristics 445 17.2.5 Mode of Operation 446 17.2.6 Preliminary Hydraulic Profile 446 17.2.7 Preliminary Equipment Selection 446 17.2.8 Power Supply 447 17.2.9 Owner Preferences 447 17.2.10 Regulatory Agency Requirements 447 17.2.11 Station Utilities 447 17.3 Detailed Layout 448 17.3.1 Piping and Instrumentation Diagrams P&IDs 448 17.3.2 Structural Considerations 450 17.3.3 Sump Design 450 17.3.4 Pipeline Orientation 450 17.3.5 Pump Room Layout 450 17.3.6 Superstructure and Interior Spaces 451 17.3.7 Architectural Treatment 451 17.3.8 Preliminary Sketches 452 17.3.9 Design Report 452 17.4 Detailed Design 452 17.4.1 Refine Hydraulics 452 17.4.2 Finalize Equipment Selection 452 17.4.3 Revise P&IDs 452 17.4.4 Detailed Layout Sketches 452 17.4.5 Final Production 452 17.4.6 Final Cross-Check 453 17.5 Examples of Large Lift Stations 453 17.5.1 Alternatives to FSIs 460 17.5.2 Column Type Solids-Handling Pumps 460 17.5.3 Submersible Pumps 460 17.6 Examples of Medium-Size Lift Stations 460 17.7 Examples of Small Lift Stations 466 17.7.1 Other Swedish Pumping Stations 469 17.8 References 471 18. System Design for Water Pumping 473 18.1 Types of Water Pumping Stations 473 18.2 Pumping Station Flow and Pressure Requirements 473 18.2.1 Flow Requirements 474 18.2.2 Pressure Requirements 474 18.3 Raw Water Pumping from Rivers and Lakes 477 18.3.1 River Intake Design Considerations 478 18.3.1.1 Low Water 478 18.3.1.2 High Water 479 18.3.1.3 Trash and Debris 479 18.3.1.4 Ice Jams 479 18.3.1.5 Frazil Ice 479 18.3.1.6 Screens for Fish Protection 480 18.3.1.7 Stable Channels and Mild Climates 480 18.3.2 Lake Intake Design 480 18.3.2.1 Tower Intakes 480 18.3.2.2 Alternative Tower Intake Designs 482 18.4 Raw Water Pumping from Aqueducts 488 18.5 Well Pumps with Elevated Tanks 496 18.5.1 Climate Considerations 496 18.5.2 Wells 497 18.5.2.1 Location 497 18.5.2.2 Water Quality 497 18.5.2.3 Water Treatment 497 18.5.2.4 Casing 498 18.5.2.5 Development 498 18.5.2.6 Well Head 498 18.6 Booster Pumping Stations 505 18.6.1 In-Line Booster Pumping Stations 505 18.6.2 Distribution Booster Pumping Stations 506 18.6.3 Packaged Booster Pumping Stations 516 18.7 Retrofitting Large Pump Basins 516 18.8 References 518 19. System Design for Sludge Pumping 519 19.1 Hydraulic Design 520 19.1.1 Flow in Pipelines 520 19.1.2 Headloss in Laminar Flow 520 19.1.3 Data for Different Sludge Types 523 19.1.4 Laminar-Turbulent Transition 523 19.1.5 Headloss in Turbulent Flow 525 19.1.5.1 Thixotropy 526 19.1.6 Simplified Headloss Calculations 526 19.2 Types of Pumps 527 19.2.1 Centrifugal Pumps 527 19.2.2 Vortex Pumps 527 19.2.3 Combined Screw-Centrifugal Pumps 528 19.2.4 Air Lift Pumps 528 19.2.5 Plunger Pumps 528 19.2.6 Progressing Cavity Pumps 529 19.2.7 Diaphragm Pumps 529 19.2.8 Rotary Lobe Pumps 531 19.2.9 High-Pressure Piston Pumps 531 19.2.10 Pump Selection 531 19.3 Pumping System Design 531 19.3.1 Calculation of System Curves 532 19.3.2 Design Procedure for Centrifugal Pumps 533 19.3.3 Design Procedure for Positive-Displacement Pumps 540 19.4 Piping System Design 542 19.4.1 Pipe Materials 542 19.4.2 Valves 543 19.4.2.1 Eccentric Plug Valves 543 19.4.2.2 Ball Valves 543 19.4.2.3 Check Valves 543 19.4.2.4 Ball Check Valves 543 19.4.2.5 Pinch Valves 543 19.4.2.6 Cone Valves 543 19.4.2.7 Gate Valves 543 19.4.3 Pump Seal Systems 544 19.4.4 Flowmeters 544 19.4.5 Grinders 545 19.4.6 Pipe Flushing and Draining 545 19.4.7 Pipe Cleaning Stations 545 19.4.7.1 Rodding 545 19.4.8 Pigging 545 19.4.9 Safety Factors for Sizing 546 19.5 Long-Distance Pumping 546 19.6 References Printbegrænsninger: Der kan printes kapitelvis