1. Straightness: Butt jointing of the straight pipe section of the coiled pipe is a very important part, which requires the accuracy of the coiled pipe blanking, the consistency of the caliber, and the tool level to automatically adjust the idler.

2. Welding: The coiled pipe is grooved according to the actual situation of the company. Most of the welding is submerged arc welding. The current and voltage of the submerged arc welding machine should be adjusted smoothly. The welding wire is selected according to the size of the groove. Before use, the flux needs to be dried and screened, so that a good product can be welded. If the current is unstable, the pores are prone to appear inside, and the surface of the weld is not beautiful like a sugar gourd. The flux is not dried and screened, and the welded steel pipe will have many pores.

3. Roundness: The roundness is controlled at the welding seam. Since the material and strength of the heated welding seam will change, if it is not bent well at the beginning, this pipe will be directly disqualified.