How a Hand Pump Works – Groundwater System Hand Pump The manual lever you move up and down. It powers the system by creating suction to lift water from underground. Piston A moving part inside the cylinder. It creates pressure changes that pull water upward and push it out through the spout. Cylinder The chamber that holds the piston. It keeps the system sealed and directs water flow during pumping. Suction Pipe The vertical pipe reaching down into the ground. It carries water from below up into