1. Downhill forming methodDownhill shaping of welded steel pipe equipment can significantly reduce edge extension.2. Increase the elongation in the middle of the billetDuring the forming process, the reduction of the opening hole pattern is increased, so that the gap between the upper and lower roll

The welding seam steel pipe of the spiral steel tube is longer than that of the straight-seam steel tube. If the tube length is L, the welding seam length is L/cos(θ). The vast majority of steel pipe defects are concentrated in the weld and heat-affected zone. The long weld means that the probabilit

1. The surface of the steel pipe is treated with anti-embroidery, which is more durable, not more than too fast oxidation, and will not form white rust on the steel pipe;2. Fully protect the steel pipe. After heating, every part of the steel pipe is plated with zinc, and the concave and convex parts

The coating methods of large-diameter water-conveying plastic-coated steel pipe plastic-coating equipment are divided into two categories: simultaneous internal coating and external coating, and separate internal coating and external coating.Process coating methods are also divided into two categori