| 摘要 |
<p>A drip irrigation line includes a plurality of emitter units secured within a water supply tube such that each emitter unit defines with the tube a flow-control passageway having an inlet port communicating with the interior of the water supply tube and an outlet port communicating with a water discharge opening in the water supply tube. Each emitter unit includes a one-way valve at one of the ports. Such port has an opening circumscribed by a cylindrical boss, and the one-way valve thereat includes a cap having a skirt of elastomeric material normally engaging the outer surface of the cylindrical boss to block reverse water flow into the flow-control passageway, but is deformable under water pressure to permit forward flow from the tube interior into the flow-control passageway.</p> |
