Pressure compensating drip irrigation system

Abstract

A drip irrigation system provides drip action of water flowing under pressure in an irrigation supply conduit. A drip emitter bonded to the exterior of the supply conduit receives water from the conduit passes the water through a pressure compensating labyrinthine channel formed internally in the emitter, and discharges the water from the channel at a greatly reduced pressure drop so the water drips at a slow drip rate. The emitter includes an elastomeric pressure compensating diaphragm contained within the emitter between the exterior of the supply conduit outer wall and the teeth of the labryinth. When water pressure is applied, the diaphragm is held in pressure contact with the ends of the teeth to form a pressure compensating side of the labyrinthine channel, for stabilizing the output drip rate of the emitter by accommodating flow pressure variations in the supply conduit. In one embodiment, the emitter is bonded to the exterior wall of the irrigation supply conduit by magnetic induction heating techniques. A region of fusible bonding material is disposed around the outside boundary of the labyrinthine channel, and the diaphragm is placed inside the emitter over the teeth of the labyrinth and the emitter is then placed over the supply conduit so the fusible bonding material overlies the exterior wall of the conduit. The bonding material is then fused by magnetic induction heating techniques to weld the inside of the emitter around the periphery of the channel to the exterior wall of the conduit.