Abstract: A method and apparatus for making drip irrigation lines, by forming two (or more) tubes in side-by-side relation joined together at a juncture including a plurality of preformed members bonded to and within the juncture at spaced locations along the longitudinal axes of the preformed members and of the juncture. Each of the preformed members includes a pair of flow-reducing, groove formations, one on each side of the longitudinal axis of the preformed member. The juncture is slit along the longitudinal axes of the preformed members to thereby form two (or more) drip irrigation lines each integrally formed with a section of the plurality of preformed members, each section having one of the groove formations serving as a flow-reducer element in the respective line.

Abstract: A moisture-responsive valve includes a water-swellable body within a housing adjacent a moisture-permeable wall thereof for controlling the movements of a valve member with respect to a valve seat in response to the moisture passing through the moisture-permeable wall. The valve member is floatingly mounted between a first spring interposed between the valve member and the housing and urging the valve member away from the valve seat, and a second spring interposed between the valve member and the water-swellable body and urging the valve member towards the valve seat.