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Centrifugal pump

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Construction, operations and maintenance
==Construction, operations and maintenance==
'''Head range''': Typically, 4–50 m per stage, with multiple-stage pumps to 200 m and more.<br>'''Yield''': Varies widely, according to many options available in the market.<br>'''Area of use''': Anywhere engine power is available.<br>
'''Trademarks''': Grundfos; Drysale; Sta-rite; and others.
 
During pumping, the condition of the engine, the water output of the pump, and the temperature of bearings should be checked, and any vibration should be reported. In some systems, valves must be closed manually just before switching off the pump, to retain water in the system. Most centrifugal pumps are not self-priming, and if the pump house runs dry, clean water has to be poured into it. The pump inlet should be maintained, and the pump and engine kept clean. A record of the pump running hours, problems, servicing, maintenance and repairs should be kept in a logbook.
 
The pump should be dismantled annually, and the rising main removed from the well and inspected. The inlet screen, foot valve and pipe threads should be checked, and any corroded or damaged threads re-cut. Badly corroded pipes should be replaced. The foot valve may need a new rubber, or it may have to be replaced. All other repairs, such as replacing the bearings or the impeller, are costly and should be carried out by qualified technicians.
 
For several reasons, centrifugal pumps are not suitable for village-level maintenance. Pump maintenance requires an organization that focuses on the training and reliability of the pump caretaker, and on raising funds to support the pump O&M. In the event of breakdown, the pump committee must be able to mobilize a trained area mechanic quickly. Centrifugal pumps are designed for specific ranges of flow and pressure, and it is important that pump characteristics and operating conditions are matched by someone properly trained. The starting torque of a centrifugal pump is relatively low, which is an advantage for windmill and solar power applications.
 
====Potential problems====
— debris, sand or other particles may enter the pump, causing abrasion damage;
— an inlet becomes clogged, causing cavitation;
— the pipeline system is damaged by severe surges in water pressure, caused by starting
and stopping the pump abruptly;
— the pump and engine are badly aligned, causing the bearings to wear out quickly;
— the main limitations of a centrifugal pump are its cost, the need to ensure a reliable
supply of electricity or fuel, and the need for skilled technicians to maintain
and repair the pump.
 
==Acknowledgements==
* Brikke, François, and Bredero, Maarten. [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http%3A%2F%2Fwww.who.int%2Fwater_sanitation_health%2Fhygiene%2Fom%2Flinkingintro.pdf&ei=cwJpT-zaO-OiiQKCst2rBw&usg=AFQjCNEWOQhTgF3a7lzhuw5OA2KmbVGxcA&sig2=Rt2EURUyGVqDcwFg6p0xAw Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff]. World Health Organization and IRC Water and Sanitation Centre. Geneva, Switzerland 2003.
==Costs==
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