JDW Self-priming deep well pumps consist of an ejector unit and a centrifugal pump.The ejector unit can be put in a 4″diameter well.These pumps are suitable to convey clean water or non_aggressive chemical fluids.They are suitable to pump water from deep well and supply water automatically by pressure tank and pressure control.It is always advisable to install a foot valve with a strainer on the bottom of inlet pipe.