低压管道出水口型分析当前机井灌区田间输水工程,都从地上防渗垄沟,转向地下低压防渗输水管道,全国已拥有各种不同型式、不同管材的低压管道约几千万米。但是低压管道在浇地出水口的设计上,则是多种多样,不拘一格,从其构造型式及其使用价值来讲,都不十分理想,都存有这样或那样的问题。现将北方地区目前使用的几种出水口型式述评如下。一、盖板式砼园形出水口这种出水口型式,是由三部分组成。即盖板部分(包括启闭丝杠),水池部分,园形槽出水口部分,这种出水口多用于预制的砼管、水泥土管以及石棉管等较大口径的地下输水管道,优点是孔口出水量大,阻水损失小,水泵扬程较低的情况下比较适用;缺点是只能和土垄沟相联接,不能配用地上输水软管,水冒出后即进入土垄沟成为明渠,均 Analysis of low-pressure pipe outlet current irrigation wells field irrigation works, all from the ground seepage ditch, turn underground low-pressure seepage water pipe, the country already has a variety of different types of pipe about a few tens of millions of meters of low pressure pipe. However, the design of low-pressure pipe in the irrigated water outlet is varied and eclectic. It is not very ideal from its structural type and its use value, and there are some problems of this kind or other. The types of outlets currently used in the northern region are described below. First, the cover concrete garden outlet This outlet type, is composed of three parts. That cover part (including the opening and closing screw), part of the pool, garden tank outlet part, this outlet for precast concrete pipe, cement pipe and asbestos pipe and other larger diameter underground water pipe, the advantage is Hole large amount of water, water loss is small, the pump lift lower case more applicable; the disadvantage is only connected to the soil and furrows, can not be equipped with ground water hose, water emerges into the ditches become open channels ,all