The Cycle

 

Default position is long end down in the water source.  20l drum filled by a rubber flap, a simple one way valve.  In that position the 220l drum is elevated and empty.  That means the cistern containing the pump is full, The float switch activates the pump. The barrel fills.  Note a flap valve on the base of the barrel stays shut by the pressure of the water on it.  The barrel becomes heavier than the 20l drum.which is almost sealed..  The outlet pipe connected to the 20l drumis now above the pipe discharge point up the hill. A one way valve has prevented water flowing back thru the pipe.  Now the water flows to its intended destination. The beam begins to pivot.

 

While the 20l drum has been emptying the 220 ltr drum has also been emptying. A rubber flap has been forced up when it came down into the same cistern that holds the pump.   The 200 ltr drum empties, The cistern fills. The float switch activates the pump - the cycle repeats.