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PVC pumps

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[[Image:Deep_well_pump.PNG|thumb|right|150px|EMAS type pump produced and used in Malawi]]
 
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The name PVC pumps covers a large number of different hand pump designs, which have in common that most parts are constructed out of PVC. PVC is used because it is often cheap, and easy to work with. As PVC is less durable as other materials such as steel, a single PVC pump should be used by a limited number of people. Because of the low price, PVC pumps are often used as family pumps. Sometimes other types of Plastic are used, such as ABS, which is UV resistant.
Some pumps, such as the [[EMAS pump]] are deep well pumps, and can pump water over a height difference of 40m. Others, such as the [[Canzee pump]] pump water up to 12-15 m deep. The [[DTU pump]] is used for extracting water from underground rainwater catchment cisterns.
==History and social context==
Because of their lightweight and low-cost design, PVC pumps are mainly suitable to be used by families or small groups of families. PVC pumps are not recommended for use by large groups of people, as this will lead to the need of frequent maintenance. An excellent overview of community hand pumps, which are suitable for larger groups, is available at the RWSN website<ref>[http://www.rwsn.ch/prarticle.2005-10-25.9856177177/prarticle.2005-10-26.2582788867/prarticle.2008-12-04.2105225472 Overview of community handpumps at the RWSN website]</ref>.
Because the water is pumped immediately to the storage tank without intermediate handling, the quality of the water remains good and the risk or recontamination is greatly reduced.
==Suitable conditions ==
{{procontable | pro=
- Low cost <br>
}}
==Technical specificationConstruction, operations and maintenance==
An important issue with all PVC pumps is the tendency of PVC to become brittle when exposed to direct sunlight for some time. Some pumps, such as the Baptist and EMAS pump, solve this by having a concrete pillar around the PVC tube, and by constructing the handle part out of galvanised steel pipe. Other pumps, such as the Canzee pump, use the UV-resistant plastic ABS. The negative effects of sunlight can be partly avoided by shielding the pump from direct sunlight, by painting PVC parts, or by protecting the PVC in some other way. In Bolivia, a strip of cloth is wound around the PVC parts, and held together with a piece of metal wire.
The operation of PVC pumps varies from design to design. Most pumps have a handle which is pushed up and down. The EMAS pump pumps water on the downstroke, in which water is pushed up through the piston pipe. This has the advantage that pressure is created, with which the water can be pumped over a distance or to a higher location. When pumped over a long distance, it is advisable to use an airchamber made from a soda bottle to even out the flow of the water, which increases the efficiency.
====Operation====The operation Many of the PVC pumps varies from design to design. Most pumps have a handle which is pushed up pump designs, such as the EMAS and downBaptist pump can be made locally. The EMAS Canzee pump pumps water on the downstroke, in which water is pushed up through the piston pipe. This has the advantage that pressure is created, with which the water can also be pumped over a distance or to a higher location. When pumped over a long distance, it is advisable to use an airchamber made from a soda bottle to even out the flow of the waterlocally, which increases the efficiencybut needs UV-resistant PVC tube.
====Maintenance====
The maintenance that is needed depends on the design of the pump. In some designs, the bottom valve will need to be replaced periodically. Valves are often made of rubber.
====Manufacturing ====Many of the PVC pump designs, such as the EMAS and Baptist pump can be made locally. The Canzee pump can also be made locally, but needs UV-resistant PVC tube.  ==CostCosts==
PVC pumps can be made very cheap. An EMAS pump can be made for about 5$, with 1$ extra for every meter of depth.
==Country Field experiences==  ==Manuals==  ==Movies== 
==External Reference manuals, videos, and links==
* [http://bushproof.biosandfilter.org/index.php?id=73 Info on Canzee pump] by Bushproof. The [http://bushproof.biosandfilter.org/assets/files/Canzee_brochure_version_240506.pdf brochure on the Canzee pump] can be downloaded.
* [[EMAS pump| EMAS pump Akvopedia article]]
* [http://www2.warwick.ac.uk/fac/sci/eng/research/dtu/pubs/tr/rwh/tr-rwh09.pdf Low cost handpumps for water extraction from below ground water tanks] by DTU.
==ReferencesAcknowledgements==
<references>
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