Abstract: An emitter unit comprises a wall defining an elongated flowpath, an inlet and an outlet for the unit, a connector for coupling the unit to an irrigation installation, two sets of oppositely directed baffles projecting into the flowpath, characterized in that each baffle terminates in a baffle tip of a width .xi. where 0<.xi.<0.25.DELTA. where .DELTA. is the minimum throughflow spacing in the emitter, the baffles of one set being respectively directed towards the inter-baffle regions of the opposite set, the tip of each baffle being substantially aligned with the tips of the opposite pair of adjacent baffles.

Abstract: A drip irrigation system comprising a thin walled thermoplastic conduit having an axially directed thick wall portion, discrete, substantially flat emitter units being heat welded to axial spaced apart locations of an inner surface of said thick wall portion adjacent outlet apertures formed in said thick wall portion, the emitter units being preferably provided with an elastomeric membrane exposed to the throughflow pressure in the conduit for the purpose of stabilizing the output rate of each emitter unit vis-a-vis possible flow pressure variations in the conduit.

Abstract: In a drip level irrigation emitter unit having flow restricting means, a control mechanism, inlet and outlet control chambers of the control mechanism, resiliently flexible membrane sealingly separating the control chambers, the membrane being displaceable with respect to the flow restricting means, the inlet and outlet chambers respectively communicating with an inlet and an outlet of the flow restricting means, the outlet chamber being formed with an outlet aperture of substantially smaller area than that of the membrane, the arrangement being such that upon the liquid pressure in the inlet chamber exceeding the liquid pressure in the outlet chamber by a predetermined amount, the membrane flexes elastically towards the outlet aperture so as to define, with a rim of the aperture, a restricted outflow path thereby limiting variations in the outflow rate.

Abstract: A pressure regulator valve comprising a housing having formed therein inlet and outlet chambers and an intermediate zone effecting communication between the chambers, a tubular sleeve slideable in the outlet chamber within a narrow annular flange integral with the housing and into and out of the intermediate zone so as to vary the available through-flow cross-section for fluid flow from the inlet chamber via an effective annular region into the intermediate zone, said sleeve, apart from a narrow length thereof adjacent said flange, being spaced from the walls of the housing so as to define therebetween regions to which the fluid has free access, a pressure displaceable element coupled to the sleeve while allowing for fluid flow through the sleeve and sealingly displaceable within a port located in the housing upstream of said sleeve and being exposed to a controlled pressure zone, biasing means acting on said element so as to bias the sleeve into said outlet chamber, a valve seating mounted in the housing and

Abstract: A self-cleaning filtration device comprising a casing; a device inlet and a device outlet formed integrally with said casing; a cylindrical filter structure mounted in said casing and defining an inner zone in communication with said device inlet, and also defining with the adjacent walls of the casing an outer zone in communication with said device outlet whereby all flow from said device inlet to said device outlet passes through said filter structure, said structure including an axial stack of annular support elements, each support element comprising a flange portion and an inwardly located axially directed skirt portion, and a sleeve-like filter element surrounding said axial stack and bearing against the outermost edges of said flange portions, at least one plunger body reciprocatably displaceable in said filter structure and including a pair of axially spaced apart sealing rings of such axial extent and respective axial separation as to ensure that at all times sealing contact is maintained between said

Abstract: An emitter unit comprises a pair of casing components and a coupling for coupling said components together via an interposed strip that extends beyond the components on all sides and is adapted to form a closed conduit such that one component is inside the conduit and one is outside. At least one of the components defines, together with the interposed strip, a flow restricting flowpath. Apertures are provided for effecting communication between said flowpath and the other component via said strip.

Abstract: An elongated dripper unit comprising an enclosure sealed at either end thereof and formed with a liquid inlet and outlet, at least one longitudinal partition formed in said enclosure so as to divide the enclosure into at least two sub-enclosures and a plurality of lateral partitions each of which extends laterally across the other enclosure from the enclosure wall to an inner longitudinal partition so as to subdivide each sub-enclosure into a plurality of cells which communicate with each other via reduced-diameter communicating apertures formed in the longitudinal partition(s), said cells including an input cell communicating with said inlet, an output cell communicating with said outlet and a plurality of intermediate cells, a liquid flow path through said unit extending from said input cell to said output cell via said plurality of intermediate cells, the liquid pressure through said unit being progressively reduced as a result of passage through said communicating apertures and as a result of repeated abr