| 摘要 |
A gated irrigation pipe is operated by a pneumatic control system which automatically opens and closes the gates. Each gate is slidable along the pipe surface and is coupled to a pair of parallel air conduits extending longitudinally along the pipe. The conduits are connected midway between their ends to a common movable pneumatic cylinder which receives therein a piston fixed to the exterior of the pipe. The conduits communicate with opposite ends of the cylinder, and serve as both an air line to the cylinder and an operating linkage which opens and closes the gates and which will not cause damage to the gates in response to differentials of expansion and contraction. A plurality of pipes thus equipped are serially connected to form an irrigation pipeline and the air conduits are interconnected at the pipe joints by flexible hose couplings which may be preset any time during each watering interval. The conduits are pressurized at the end of each interval to change the gates in accordance with a sequential irrigation plan without the necessity of the operator being present to manually open and close the gates.
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