Spiral steel pipe production technology (1) raw materials that is, strip coil, welding wire, flux. They are subjected to strict physical and chemical tests before they are put into use. (2) The butt joint of strip steel head and tail adopts single-wire or double-wire submerged arc welding, and

Spiral steel pipes should be subjected to mechanical performance test, flattening test and flaring test before leaving the factory, and must meet the requirements of the standard. The quality inspection methods of straight seam steel pipes are as follows:1. Judging from the surface, that is, in appe

Generally speaking, the diameter of steel pipes can be divided into outer diameter, inner diameter, and nominal diameter. The outer diameter of the pipe is a hot-dip galvanized seamless steel pipe with the letter D, followed by the size and wall thickness of the outer diameter.