Village tuble problem – The tube well casing houses the inlet, cylinder, piston valves and rising main of a “down-the-hole” type hand pump. Casing to support the external surfaces of the borehole against collapse may be needed . Either temporarily or permanently, and is often made of which is both cheap and inert. Seepage down the tube well bore is prevented by the sanitary seal. Seepage from the ground above the aquifer is excluded by the lengths of plain casing. Water to be pumped is admitted through slots in the lower lengths of casing.
Water abstracted from aquifers in relatively soft ground usually contains sand or silt particles. Which are liable to cause rapid wear to pump valves and cylinders (and dissatisfaction among consumers). Methods of preventing these particles from reaching the pump are of two general types, screening and sand/gravel packing.