“风送法”钢管水泥砂浆内防腐工艺已被广泛采用,该工艺具有施工机具通用、操作方便、施工速度快,便于现场施工,成本低等优点。目前用这种方法防腐的管道存在一个较普遍的问题,就是涂层不均匀,管子的上部薄,下部厚。特别是大口径管子尤为突出。管道局77年施工的宁于水管线(φ720毫米,长110公里)上、下厚度有时竟达3毫米和20多毫米之差。为何出现这种情况,怎样解决?现对比作一分析,并提出些相应的改进措施与同行研讨。一、上薄下厚的第一个原因,是水泥砂浆 The anti-corrosion technology of “wind-sending method” steel pipe cement mortar has been widely adopted. This process has the advantages of universal construction tools, convenient operation, fast construction speed, convenience for on-site construction, and low cost. One of the more common problems with pipes that are currently protected by this method is the uneven coating, the thin upper part of the pipe and the thick lower part. Especially large-diameter pipes are particularly prominent. The upper and lower thicknesses of the Ningyu Water Pipeline (φ720 mm, length 110 km) constructed by the pipeline bureau in 77 years may sometimes reach a difference of 3 mm and 20 mm. Why does this happen, and how do we solve it? We will now compare the analysis and propose some corresponding improvement measures and peer research. First, the first reason for thin thickness is cement mortar