FIVE-STAND SIZING MILL FOR CALIBRATION OF LONGITUDINAL ELECTRIC-WELDED PIPES Russian patent published in 2024 - IPC B21D3/05 B21C37/30 

FIELD: pipe welding production.

SUBSTANCE: invention can be used for calibration of longitudinal electric-welded pipes. Sizing mill comprises stand with two sizing rolls and four stands with four sizing rolls following it. Calibration rolls of the stand with two rolls are located horizontally at the bottom and on top of the pipe at angle of 90° to the pipe forming plane. Said rolls have the possibility of converging and separating relative to the pipe with the initial diameter with provision of transfer of residual internal stresses of pipe into plastic deformation by means of its flattening with formation of oval. Rolls have concave surface, radius of which is 2–10 times greater than radius of produced pipe, and arc of pipe circumference has maximum angle of 120°.

EFFECT: as a result, deviation of the diameter value at the ends of the pipe from the requirements of the normative documentation is ensured.

1 cl, 2 dwg