1.4 Engineering PracticeDuring the

1.4 Engineering PracticeDuring the installation and construction of galvanized steel pipes, we must take the following countermeasures in time for the above-mentioned common problems: ① When cutting metal pipes, the operator must complete preventive measures and ensure that the pipe mouth of the saw pipe is kept flat. Straight, no burrs; ②The thickness of the protective layer of the pipeline is at least 15mm, and the strength of the wall mortar is at least 10MPa; ③When the non-galvanized steel pipe is connected by threads, it is required that the two welding spans must be connected to the grounding wire. Connection: When the galvanized steel pipe is connected by screw thread, its two ends should be connected with a special grounding clamp to connect with the jumper grounding wire; ④When the thickness of the galvanized pipe wall is less than 2mm, it cannot be carried out with the help of a bushing Welding requires that the casing and screws must be matched with each other, and the electrical continuity test must be completed; ⑤After the pipeline is installed, it is necessary to carefully protect the finished product.2Protective ground wire installation problems and prevention countermeasures for metal wire pipe2.1 PhenomenonThe cross-section of the metal protective ground wire is too small, which completely fails to meet the standard requirements; the anti-corrosion paint coating of the simmering pipe and the welding part is not perfect; the inner concrete protective layer work is done Not perfect enough.2.2 Reasons①When the metal wire tube and the ground wire are welded to each other, the cross-sectional area relationship between the ground wire and the wire in the tube is usually not considered; ②The ground wire is confused with the importance; ③The purpose of painting the metal wire tube with anti-rust paint The location is not clear enough; ④Before the concrete was poured, the pipe was not padded with prefabricated concrete blocks, resulting in insufficient protection of the bottom surface.2.3 Preventive measures① When the metal pipeline is connected to the ground wire, the two sections should be welded with quasi 4mm galvanized iron wire or steel bar of quasi 6mm or more. Therefore, the cross-sectional area of ​​the ground wire welded to the main line pipe is at least 1/2 of the cross-sectional area of ​​the phase line passing through the pipe, and when it is a branch line, it is at least 1/3 of the cross-sectional area of ​​the passing phase line. At the same time, the ground wire The welding length should be at least 6 times the diameter of the connecting wire. ②A layer of anticorrosive paint should be applied to the surface of the in-line tube. In the actual construction, except for the metal line pipe laid in the concrete, other parts must be painted with a layer of anti-corrosion paint. For metal pipelines laid in the soil, the thickness of the pipe must be at least 3mm or more. During the pouring process, make sure that the precast concrete blocks can cushion the pipe, so that the thickness of the concrete protective layer around the pipe is at least 5cm.