The installation and use of spiral steel pipes involve strict technical requirements that must be adhered to based on actual conditions and operational procedures to ensure quality. During the general use of spiral steel pipes, attention should be paid to the following points:
The installation of spiral steel pipes should be carried out according to the design drawings. Pipe supports should be prefabricated based on site conditions, followed by punching and shearing according to the design and site requirements. Then, use a polishing machine to polish the grooves before proceeding with welding. The quality requirements for installation include ensuring that the deviation for vertical installation of risers is less than 3mm per meter, and the deviation for horizontal installation is less than 1mm. Branch pipes should not be welded at weld seams, and welding should be avoided at bends.
Before using spiral steel pipes, proper construction preparation is essential. Ensure that pipe trenches are excavated, pipe shafts are constructed, and all necessary spiral steel pipes and tools, including welding machines, cutting machines, electric hammers, polishing machines, etc., are fully prepared. Only after completing these preparatory steps can installation commence.
Regarding surface mechanical damage, the repair method of adding a sleeve is typically chosen. The sleeve consists of two parts, with two longitudinal welds formed by welding two strips using butt welding. The advantage of this method is that there are no welds on the body of the steel pipe. The longitudinal seam is a butt weld with a backing plate, and the pipe body itself serves as the backing plate for the upper and lower sleeves. Regardless of the method chosen, the sleeve must be tightly secured around the steel pipe.
Welding should be straight, with complete welds, and the weld surface should be free from burn-throughs and cracks. When scratches do not result in leaks, the two circular fillet welds between the sleeve and the steel pipe body do not need to be welded. However, if leaks occur, these welds must be made. In this scenario, the sleeve bears the internal pressure generated by the liquid it contains. Therefore, under such conditions, the thickness of the sleeve should generally be no less than that of the pipe wall.
