A hand pump is a pump that uses the power that is supplied by the user's own muscles for its operation. It uses suction to draw water up from a well. The fulcrum causes the piston rod to go up as the hand is pushed down, thus taking with it the piston and its rings. This in turn causes a check valve, often referred to as a foot valve, at the bottom of the pump to open and draws water. When the piston goes down, the pressure makes the check valve to close, thus trapping the water above the piston. This cycle repeats itself for as long as the hand pump is in use.