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3.控制、量测及保护装置为了控制微灌系统或确保系统正常运行,系统中必须安装必要的控制、量测及保护装置,如阀门、流量和压力调节器、流量表或水表、压力表、安全阀和进排气阀等。 (1)进排气阀进排气阀能够自动排气和进气,水压升高到某一数值时又能自动关闭。在微灌系统中,进排气阀主要安装在管网中最高位置处和局部高地。当管道开始输水时,管中的空气受水的“排挤”向管道高处集中。当空气无法排出时,就会减小过水断面面
3. Control, measurement and protection devices In order to control the micro-irrigation system or to ensure the normal operation of the system, the necessary control, measurement and protection devices such as valves, flow and pressure regulators, flow meters or water meters, pressure gauges , Safety valve and intake and exhaust valves. (1) into the exhaust valve into the exhaust valve to automatically exhaust and intake, water pressure to a certain value can be automatically shut down. In the micro-irrigation system, intake and exhaust valves are mainly installed in the highest position in the pipe network and local high ground. When the pipe begins to deliver water, the air in the pipe is “squeezed out” by the water to concentrate at the height of the pipe. When the air can not be discharged, it will reduce the cross-section of water