54
edits
Changes
no edit summary
Direct action handpumps are usually made of PVC and other plastics, and are installed on boreholes of limited depth. A plunger is attached to the lower end of a pump rod, beneath the groundwater level. The user moves the pump rod in an up-and-down motion, using a T-bar handle. On the up-stroke, the plunger lifts water into the rising main, and replacement water is drawn into the cylinder through the foot valve. On the downstroke, the foot valve closes, and water passes through a one-way valve in the plunger and is lifted on the next up-stroke. Because direct action handpumps have no mechanical advantage, such as the lever or fly-wheel of a deep-well handpump, direct action pumps can only be used to depths from which an individual can physically lift the column of water (about 12 m). However, the mechanical simplicity, low cost and lightweight construction makes these pumps well equipped to meet O&M objectives at the village level.
'''Trademarks:''' Blair; Ethiopia BP50; Malawi Mark V; Wavin. '''Public Domain:''' [http://www.rural-water-supply.net/en/implementation/handpump-overview/nira-af-85-pump Nira AF85; AF-85], [http://www.rural-water-supply.net/en/implementation/handpump-overview/tara-pump Tara; WavinPump], [http://www.rural-water-supply.net/en/implementation/handpump-overview/malda-pump Malda]
==Suitable conditions==