SEVAI Rural Technology Centre in Sirugamani as supported by Foundation Hirzel and OFI, has fixed Tara Pump, the “Direct Action Pump for Low Lift Wells” for demonstration purpose. It uses a buoyant pump rod that helps to reduce the forces on the handle. The Tara pump is a public domain pump that operates by the direct action of the operator.
Since there is no mechanical advantage afforded as in lever action pumps, the effective depth of the Tara pump is limited to about 10-15 meters. The operator lifts up and pushes down on a T-handle that is directly connected to the pump rod. This direct connection eliminates the need for bearings and axles, as on lever action pumps and allows water to be delivered to the spout on both the upstroke and the down-stroke. It is not designed for heavy-duty use, and can serve small communities of about 100 persons.
The pumps are generally installed in collapsible boreholes drilled with the sludger method. This is made possible by the inclusion, below the foot valve, of a lower well assembly. This lower well assembly includes a well screen, a sand trap, and a cutter. The Tara pump can be inserted directly into a coarse sand aquifer. The lower well assembly allows water to flow from the aquifer to the pump cylinder.In effect, the lower well assembly performs the same function as the well screen in a rigid tube well casing.
Only very simple tools are needed to assemble and disassemble Tara shallow well hand pumps. Village caretakers can easily work on and maintain a Tara pump.The open-cylinder design allows for easy removal of the piston assembly and the foot valve.It can be used for drinking water and irrigation of family gardens too.