Solar pumping CONSTRUCTION DETAILS AND WORKING PRINCIPLE: 1. Black surface tank: outer surface of the tank absorbs sun rays and gets heated. The tank initially filled with air. This air gets evaporated by absorbs heat from metal body (tank). 2. Inlet and outlet valve: initially these valves are closed. The air in the tank continuously expanded but the valves are closed so pressure rises. 3. Inlet valve open: To open the inlet valve the air expands in into water (one direction flow of air). The continuous drained out of air into atmosphere by expansion of air, vacuum space (low pressure) is created in the tank. The vacuum cannot ‘’suck’’ but the atmosphere pressure to push the liquid up into the tank by difference in pressure head. Even if all air is expand out, water will only raise 10.3 m (34feet) because at 10.3 m equaling the air pressure.