| 摘要 |
An irrigation pipe laying crosswise of a series of furrows has gate valves mounted in its side spaced to match each furrow. Each gate valve includes a generally elliptical, elastomeric, grommet-like frame fitting on the periphery of a recessed lip portion of the pipe defining an opening, and also includes a tubular slide slidable in the frame between a closed position and three open positions, one perpendicular to the pipe and two others cocked to either side to direct water to the outer of the three furrows.
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