The site or warehouse of thermal insulation spiral steel pipe products should be chosen in a clean place with smooth drainage and away from factories and mines producing harmful gas or dust. After cutting into a single steel pipe, each batch of steel pipe head three to carry out a strict first inspection system, check the mechanical properties of the weld, chemical composition, melting condition, spiral steel pipe surface quality and non-destructive inspection, to ensure that the pipe making process qualified, before formally put into production. Spiral steel pipe production process is simple, high production efficiency, low cost, rapid development. Remove weeds and all debris from the site and keep the steel pipe clean. In the warehouse shall not be stacked with acid, alkali, salt, cement and other corrosive materials to steel pipe. After more than a month of spiral steel pipe, the problem finally appeared in full swing. An unnamed CISA official told China Business News that according to the most conservative estimates, 70 percent of the companies are either suspending production or limiting production. When the pipe is subjected to internal pressure, there are usually two main stresses on the pipe wall, namely the radial stress δY and the axial stress δX. The synthetic stress δ=δY(L / 4Sin2 α+cos2α)1/2 at the weld, where, α is the helix Angle of the spiral steel pipe weld.

The strength of spiral steel pipe is generally higher than that of straight seam welded pipe, and it can be used to produce welded pipe with larger diameter with narrower blank, or welded pipe with different diameter with the same width blank. The weld gap control device is used to ensure that the weld gap of spiral steel pipe meets the welding requirements, and the pipe diameter, staggered edge and weld gap are strictly controlled. American Lincoln welding machine is used for single wire or double wire submerged arc welding for internal and external welding, so as to obtain stable welding specifications. More than a month ago, the European Union decided to launch a countervail investigation into Chinese spiral steel pipes, and the United States followed suit. All this is directly related to the interests of more than 3000 spiral steel pipe manufacturers in China. Before this, the capacity of this field is mostly designed in accordance with export sales.

The strength of spiral steel pipe is generally higher than that of straight seam welded pipe, and the welded pipe with larger diameter can be produced with narrower blank.