Abstract: Multiple unit drip irrigators use several self-contained on-line drip irrigation devices, each comprising a distinct housing having a liquid inlet, a tubular liquid outlet and containing a labyrinthine liquid path between such inlet and outlet. A common manifold contains the several drip irrigation devices. Such manifold has a common liquid inlet communicating through a space in that manifold with the liquid inlets of the drip irrigation device housings. The manifold has as many distinct internal supports for the housings of the drip irrigation devices as there are drip irrigation devices. Each of such internal supports has a bore for receiving the tubular liquid outlet of one of the housings of the on-line drip irrigation devices and each of such internal supports has an individual outlet terminal extending from the bore in that internal support to an outside of the common manifold.

Abstract: A drip irrigator consists of only two substantially parallel discs spaced from each other by the depth of a labyrinthine path extending about a central region between these discs and between a liquid inlet and a dripper outlet and consisting of the material of at least one of these discs. The drip irrigator may have a pair of liquid ports on the discs extending from opposite sides of the central region. A method of making a drip irrigator forms the labyrinthine path in a first disc to extend in turns from a liquid inlet about an axis to a dripper outlet. That labyrinthine path initially is laterally open in a plane perpendicularly intersecting that axis, and that labyrinthine path is laterally closed with another disc in that plane.