1.4工程实践 在镀锌钢管安装施工中，针对上述质量通病，我们必须及时采

1.4 Engineering Practice <br><br>During 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. <br><br>2Protective ground wire installation problems and prevention countermeasures for metal wire pipe <br><br>2.1 Phenomenon <br><br>The 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. <br><br>2.2 Reasons <br><br>①When 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. <br><br>2.3 Preventive measures<br><br>① 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.

1.4 Engineering practice<br><br>In the installation and construction of galvanized steel pipe, in view of the above-mentioned quality general disease, we must take the following countermeasures in a timely manner: (1) when cutting the metal pipe, the operator must complete the preventive measures to cross the bottom work, to ensure that the saw pipe port to remain straight, no burrs appear; (2) The thickness of the protective layer of the pipeline is at least 15mm, and the mortar strength of the wall is at least 10MPa; (3) When a non-galvanized steel pipe is connected by thread, two welding spans are required to be connected with the ground wire; When a galvanized steel condule is threaded, the connection at both ends is connected with a special ground card in order to connect with a jumper ground wire; (4) When the thickness of galvanized pipe wall is less than 2mm, welding can not be carried out with the help of casing, and the casing and screws must be matched with each other, and the electrical continuity test is completed; (5) After the pipeline is installed, it also needs to do a good job of product protection.<br><br>2 Metal pipeline protection ground installation problems and prevention and control measures<br><br>2.1 Phenomenon<br><br>The cross-section of the metal protective ground is small and can not meet the standard requirements at all. The anti-corrosion paint brush in the pipe and welding area is not perfect enough; The work of the inner concrete protective layer is not perfect.<br><br>2.2 Reason<br><br>(1) When the wires and ground wires are welded to each other, the cross-sectional relationship between the ground wire and the wires in the tube is not usually considered; (2) confusing the ground line with its importance; (3) the purpose and position of painting anti-rust paint in the metal wire pipe is not clear enough; (4) Before pouring concrete, the pipe is not cushioned with concrete prefabribriced blocks, resulting in the bottom layer protection layer work is not thorough enough.<br><br>2.3 Preventive response<br><br>(1) When the metal pipeline and ground wire are connected, the two sections shall be welded using quasi-4mm galvanized wire or quasi-6mm or more steel bars. Therefore, the ground section area welded with the trunk pipe is at least 1/2 of the cross-phase cross-sectional area of the pipe, and when it is a branch line, at least 1/3 of the cross-sectional area of the cross-sectional line. At the same time, the welding length of the ground wire should be at least 6 times the diameter of the connecting line. (2) The surface of the online tube should be coated with a layer of anti-corrosion paint. In the concrete practice construction, in addition to laying in the concrete metal pipe, other parts must be coated with a layer of anti-corrosion paint. For metal lines laid into the soil, the thickness of the pipes must be at least 3mm or more. During the pouring process, make sure that the prefabrio concrete blocks can cushion the pipe so that the thickness of the concrete protective layer around the pipe is at least 5cm.

1.4工程实践 在镀锌钢管安装施工中，针对上述质量通病，我们必须及时采取以下几点对策：①对金属管子进行切割时，操作人员必须完成预防措施交底工作，确保锯管管口要保持平直，没有毛刺的出现;②管路的保护层厚度至少为15mm，同时，墙体砂浆强度至少为10MPa;③当非镀锌钢管使用螺纹来连接时，要求两段焊跨要和接地线相连接;镀锌钢导管使用螺纹连接时，其两端连接处要和专用接地卡相接，以便和跨接接地线相连接;④当镀锌管壁的厚度小于2mm时，不能借助套管进行焊接，而要求套管和螺钉必须相互配套，并且完成电气连续性试验;⑤管道在完成安装后，还需要认真做好成品保护工作。 2金属线管保护地线安装问题和防治对策 2.1现象 金属保护地线的截面偏小，完全达不到标准要求;煨管和焊接处的防腐漆涂刷不够完善;内层混凝土保护层工作做得不够完善。 2.2原因 ①当金属线管和地线相互焊接时，通常不会考虑地线与管内导线的截面积关系;②将地线左右与重要性相互混淆;③在金属线管涂刷防锈漆目的与位置不够明确;④在混凝土浇注之前，未将管子用混凝土预制块垫起，导致底面的保护层工作做得不够彻底。 2.3预防对策 ①当金属管线和地线相连接时，其两段要使用准4mm镀锌铁丝或者是准6mm以上的钢筋进行焊接。因此，和干线管焊接的地线截面积至少是管内穿过相线截面积的1/2，而当为支线时，则至少为所穿过相线截面积的1/3.同时，地线的焊接长度应至少为连接线的直径的6倍。②在线管表面要涂刷一层防腐漆。在具体实践施工中，除铺设在混凝土内的金属线管，其它部位都必须涂刷一层防腐漆。对于铺设到土壤中的金属管线，其线管的厚度必须至少在3mm以上。在浇注过程中，要确保预制混凝土块可以把管子垫起，这样一来，在管子的四周混凝土保护层的厚度至少为5cm。<br>