The principle of the pump is attractive because it allows thin flexible hoses to be used, making the pump easy to install or remove without the need for special tools or equipment. Replacing spare parts is usually easy; only the replacement of the diaphragm may need the assistance of a skilled mechanic. It is possible to install several pumps in a single well or borehole.
===Suitable conditions===
'''Range of depth:''' 10–70 m.<br>
'''Area of use:''' Burkina Faso, Cameroon, Ghana, Liberia, Mali, Mauritania, Niger.<br>
===Construction, operations and maintenance===
The pump is operated by pushing down on a pedal, usually by foot, but sometimes with a handle. Depressing the pedal can take a considerable effort, as much as the bodyweight of the user, and the pump must be built to withstand this. Every day, the pump head, platform and surroundings must be cleaned, and the nuts and bolts tightened. Each month, the drive piston, rings and guide bushing need to be checked and replaced if necessary. At least once a year (more often if borehole conditions warrant it), the downhole parts of the pump have to be checked and the entire pump washed with clean water. The pump can be extracted from the well by the village caretaker and reinstalled, all within one-half hour. Only one spanner is needed to service the pump. Also, the plunger seals in the cylinder at the pump stand cost little and can easily be replaced by the pump caretaker.
needed to produce the pumping element; in many countries, these parts will have to be imported.
===Costs===
In 1986, a complete pump that operated to a depth of 30 m cost US$ 860. In Burkina Faso and Benin in 1993, a Vergnet model pump cost US$ 1460–1820 (including 10% VAT), depending on the installation depth.
===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.