Flexible pipe for trickle irrigation

摘要

A flexible pipe contains trickle irrigation emitters positioned inside the pipe. It consists of an inner plastics tube provided with spaced chambers and an outer plastics tube fused with the inner tube and covering all chambers, the outer tube being perforated by water outlets in respect of each chamber. The bottom of each chamber is perforated by water inlet openings, and each chamber contains a rigid, oblong emitter unit having a recessed top surface with a raised rim tightly fused to the outer tube; the bottom surface of the emitter unit is flat and parallel to the chamber bottom and contains a flow-restricting duct which communicates at one end with the chamber bottom and at the other with the recessed top surface. A flat, flexible wafer is positioned between the chamber bottom and the emitter unit, adapted to be urged into the flow-restricting duct by water pressure in the pipe, whereby increased pressure reduces the cross-section of the duct and increases the flow resistance, in a manner that the output remains constant over a wide range of pressures.