Changes

'''Maintenance of direct action pumps ''', for instance, is relatively simple and can be taught to users or caretakers, sometimes within a few hours. For preventive maintenance, usually only one or two people are needed. Daily activities consist of checking the pump performance and the appearance of the water (if it is cloudy with silt, the borehole must be cleaned). Annually, the pump should be taken apart and checked. Small repairs include replacing worn cupseals and washers, straightening bent pump rods, and replacing corroded lock nuts. To carry out major repairs (e.g. a broken pump rod or rising main, cracks in the welding of metal parts), skilled help may be needed. O&M can be organized at community level, and since maintenance is relatively simple, good organization will result in a reliable service. '''Potential problems'''* Worn washers, plungers and foot valve parts * Abrasion of the seal on the PVC cylinder and between the pump rod and rising main * Broken or damaged handles * The maximum lift is limited to about 12 m. * The force needed to pump the water may be too great for children, especially if the water table is below 5 m.