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(一) 日本日本灌溉渠系从渠道到田间分总干、干渠、支渠三级明渠和干管、支管、灌水管三级管道。总干、干渠常用 L 型预制钢筋混凝土构件衬砌,支渠一般用 U 型钢筋混凝土或波纹钢板(用于地基差的地段)制的渠槽。干管直径最大的主要采用树脂纤维管,并次采用钢、球墨铸铁、予应力混凝土、石棉水泥等材料制成;支管常用聚氯乙烯管和承插式石棉水泥管、灌水管则用铝管或聚氯乙烯管。管道的驼峰部位都装有自动排气阀。排气阀内有一浮球,阀内有气时,阀门敞开,可向外排气,阀内充满水时,浮球上浮顶住阀门,水不能外溢。
(A) Japan Japan’s irrigation canal system from the channel to the field divided into general trunk, trunk canal, branch canal three open channels and trunk, branch, irrigation pipe three. The main trunk and dry-channel L-shaped prefabricated reinforced concrete components commonly used lining, branch canal generally U-shaped reinforced concrete or corrugated steel (for the foundation of the lot) trench. The main diameter of the main pipe using resin fiber tube, and the second use of steel, ductile iron, prestressed concrete, asbestos cement and other materials; branch commonly used polyvinyl chloride pipe and socket type asbestos cement pipe, irrigation pipe with aluminum pipe Or PVC pipe. Pipe hump are equipped with automatic exhaust valve. Exhaust valve has a float ball, the valve has gas, the valve open, can be discharged to the outside, the valve is full of water, the floating ball floating on top of the valve, the water can not spill.