Water-Lifting Devices – Pumps - Practices of Irrigation and On-farm Water Management - page 434

12.6 Other Types of Pumps ........................... 458
12.6.1 Air-Lift Pump .......................... 458
12.6.2 Jet Pump ............................ 459
12.6.3 Reciprocating Pump/Bucket Pump ................. 461
12.6.4 Displacement Pump ....................... 462
12.6.5 Hydraulic Ram Pump ....................... 462
12.6.6 Booster Pump .......................... 462
12.6.7 Variable Speed Pump ....................... 462
12.7 Cavitation in Pump ............................ 463
12.7.1 Cavitation in Radial Flow and Mixed
Flow Pumps ........................... 463
12.7.2 Cavitation in Axial-Flow Pumps .................. 463
12.8 Power Requirement in Pumping ...................... 464
12.9 Pump Installation, Operation, and Control .................. 465
12.9.1 Pump Installation ......................... 465
12.9.2 Pump Operation ......................... 466
12.9.3 Pump Control .......................... 467
12.10 Hydraulics in Pumping System ....................... 468
12.10.1 Pressure Vs Flow Rate ...................... 468
12.10.2 Pressure and Head ........................ 468
12.10.3 Elevation Difference ....................... 469
12.11 Pumps Connected in Series and Parallel ................... 469
12.12 Pump Performance and Pump Selection ................... 469
12.12.1 Pump Performance ........................ 469
12.12.2 Factors Affecting Pump Performance ................ 469
12.12.3 Selecting a Pump ......................... 470
12.12.4 Procedure for Selecting a Pump .................. 470
12.13 Sample Workout Problems on Pump .................... 473
Questions .................................... 476
Every day, millions of water pumps deliver water from wells to homes, farms, and
businesses. A pump is the link to the water resource. Without pumps, we could
not access ground water. As energy costs continue to increase, developing more
efficient equipment will contribute to saving energy. Significant opportunities exist
to reduce pumping system energy consumption through smart design, retrofitting,
and operating practices. Cost of water supply depends on the appropriate selection
(type and size for the prevailing condition) and efficiency of the pumping equip-
ments. Each type of pump has its merits and demerits. Proper selection of pumps,
motors, and controls to meet the requirement is essential to ensure that a pump-
ing system operates effectively, reliably, and efficiently. The basics of pump control
systems and hydraulic system are useful in pump operation. A proper discussion
of pumping considers not just the pump, but the entire pumping “system” and how
the system components interact. The recommended systems approach to evalua-
tion and analysis includes both the supply and demand sides of the system. Greater
details regarding the characteristics of each pump, factors influencing optimum