After ASME SA106 grade B seamless pipe processing is completed, there will be some twists and turns, and the reducing of these twists and turns will depend on straightening machine to complete. Therefore, almost all the processed seamless steel pipes have to be cold straightened by straightening machine.

The twists and turns of ASME SA106 grade B seamless pipe are caused by improper adjustment of rolling mill, residual stress during rolling and uneven cooling along the section and length of SA106 grade B seamless pipe. Therefore, it is not possible to get very straight pipes directly from the rolling mill. Only by cold straightening the tortuosity of SA106 grade B seamless pipe can the technical conditions be satisfied.

The basic principle of straightening is to make the ASME SA106 grade B seamless pipe undergo elastic-plastic twists and turns from large to small, so it is necessary for SA106 grade B seamless pipe to be repeatedly tortuous in the straightening machine. The degree of repeated twists and turns of SA106 grade B seamless pipe is mainly determined by the adjustment of straightening machine.