Analysis of Seamless Steel Pipe Dimension Excess

Seamless steel pipe dimension excess can be categorized into five types: uneven wall thickness, wall thickness excess, outer diameter excess, bend, and length excess.

Uneven wall thickness of seamless steel pipe: Uneven wall thickness across the same cross-section of the pipe can occur for a variety of reasons, such as uneven heating of the billet or improper adjustment of the piercing machine's rolling line. Inspection requires measurement of each pipe, and ends with the removal of those pipes with uneven wall thickness.

Uneven wall thickness of seamless steel pipe: Unidirectional wall thickness excess can occur for a variety of reasons, such as uneven heating of the billet or improper adjustment of the piercing machine. Inspection requires measurement of each pipe, and ends with the removal of those pipes with uneven wall thickness. Excessive length excess should result in a revision or scrapping.

Outer diameter of seamless steel pipe: Exceeding the outer diameter of the pipe can result from excessive wear of the sizing machine's die. Inspection requires measurement of each pipe, and any excess should result in a revision or scrapping.

Bending of Seamless Steel Pipes: Seamless steel pipes may be uneven along their length or exhibit a goose-head-shaped bend at the ends. This may be caused by, for example, localized water cooling during manual heat inspection. If the bend exceeds the specified value during inspection, it may be straightened a second time; otherwise, it will be scrapped. "Goose-head bends" that cannot be straightened should be removed.

Excessive Length of Seamless Steel Pipes: Seamless steel pipes may exceed the specified length. This may be caused by, for example, excessive billet length. During inspection, long-length pipes may be recut or reclassified, while short-length pipes may be reclassified or scrapped.