Welded tube bending refers to long rolling (type, rod, pipe) in the longitudinal extent of the bending direction. Per meter length of the curved chord is called curvature per meter; total length of the curved with the total chord ratio is called the total length of the total curvature. Bending of all kinds of rolling has the provisions in product standards. Causes bending of the metal timber is thermal processing or heat treatment cooling rate uneven shrinkage inconsistent; rolling not put straight before cooling; bend during transport and so on. Prevent or correct approach is mainly to improve the cooling bed structure and lifting tools, improve packaging. After bending occurs, the most effective remedy is by straightening machine straightening.
Pipe in the longitudinal direction of the curved shape, which is shown with the number that is called the degree of curvature of the curve. Curvature of the standards set forth in generally divided into the following two: local curvature: with a meter-long ruler by the maximum amount of bend in the pipe, measured chord (mm), is the local curvature of the value of its units mm / m, said method according to 2.5mm / m. This method is also applicable to the bending of the tube end.
The total full-length Bending: with a string, from the tube ends of taut, the largest measuring pipe bend chord (mm), and then converted into a length (in meters) of a percentage, that is the whole pipe length direction bending length.