File:Piston pump.png

Schematic of a double-acting piston pump (the main proposed AT pump for water supply pumps), designed by User:KVDP. The schematic is based on the double-acting piston pump at http://www.fao.org/docrep/010/ah810e/AH810E06.htm#6.1.1 , and http://www.pumped101.com/recip.pdf , but some modifications have been implemented; these include:

• redesign of the pump lay-out so that the water is pushed directly into the right direction by the piston; this would allow higher water pressures (by using a more powerful engine) and increased efficiency. If the redesign was not to have been done, damage to the pipe due to higher pressure might could be inflicted.
• reduction in the amount of valves (to 2 from 4 in the original design). As there are thus less moving parts, the pump is more durable and less prone to failure.
• overall simpler design; more easy to construct and to comprehend

Note that for the stroke, the piston should only move just past the water inflow hole; any longer a stroke would reduce the efficiency of the pump since the water inflow pipe does not feature a valve (any water thus entering and moving to behind the piston when the piston is at its furthest position, and any water moving in front of the piston moving toward the front of the piston will lose any momentum that it had when entering the pump).