Pump Jack - A deep well piston pump. The piston and cylinder is submerged in the well water and actuated by a rod inside the drop pipe, powered by a motor at the surface. This is an old-fashioned system still used for extremely deep wells, including solar pumps as deep as 1000 feet. Sealed Piston Pump - A type of pump in which water is drawn in and forced out of a chamber by a piston mechanism. The pistons have a very short stroke, allowing the use of flexible gaskets to seal water out of the piston mechanism.
Check valves let water into and out of the chamber.
Surface Pump - A pump that is not submersible. It must be placed no more than about 20 ft. above the surface of the water in the well. A positive displacement mechanism used in low volume high lift surface pumps and booster pumps. Durable and efficient, but requires cleanly filtered water due to its mechanical precision. They are used in DC surface pumps and also in some DC submersible pumps.