Hydraulic ram pumps and Sling Pumps

WaterAidThe interior of the superstructure should be darker than the daylight outside and the superstructurebuilding should be well ventilated so as to allow the flow of air into the pit. The pit should have a ventpipe which should be at least 100mm diameter and should extend from the pit to about 1 metre abovethe roof, and the top of it should be fitted with a fine-mesh stainless steel, GRP or aluminium flyscreen.Flies which are drawn by smell into the pit will be attracted up the vent pipe by the brightnessof daylight at the top it, but cannot escape because of the screen. Wind passing over the vent pipe willcause an updraught, removing any smell and helping to draw flies up to the top of the pipe.http://www.wateraid.org.uk/in_depth/technology_notes/303.asp (4 of 6) [1/13/2005 12:49:58 PM]