亚洲综合网一区二区三区_91麻豆视频国产_日本特级淫片免费_婷婷伊人久久成人精品视频_国产一级淫一区二区波多野结衣_任你干精品视频免费_国产一级精品夜夜爽_日韩超清无码?V_亚洲欧洲高清无码_国产成人18黄网站在线观看网站

1. Firstly, the surface of steel plate shall be derusted by shot blasting machine to improve the adhesion of paint.

2. For the camber of the weld between the web and the upper cover plate, the corresponding conic, quadric and quadric superposition curves shall be selected according to the span, industrial and mining conditions of the crane,

The arch height of selected points is calculated by computer, the plate sample is made, and the setting out and blanking of the web plate are carried out.

3. The butt welding of the crane main beam includes the welder assembly and reasonable welding process. Through the symmetrical welding of two or four people, the current and welding speed shall be reasonably selected to reduce the welding deformation of the crane.

4. For butt welds of crane main beam, end beam, web and upper and lower cover plates, all longitudinal welds shall adopt submerged arc automatic welding, and 100% flaw detection shall be carried out after welding.

5. The docking of crane bridge and the docking of portal main beam and end beam shall be set out, positioned, lifted and overturned on the platform, with geometric dimensions.