An apparatus for polishing a butt weld includes a machine frame; a polishing mechanism, including a rotating arm, a supporting column rotatably mounted on the rotating arm, and a polishing roll rotatably mounted on the supporting column in a circumferential direction of the polishing roll; an angle limiting assembly, movably mounted on the rotating arm, the angle limiting assembly limiting an angle at which an outer side end of the supporting column swings upward; a roll driving part, mounted on the rotating arm. The roll driving part is in transmission connection with the polishing roll and drives the polishing roll to rotate on the supporting column in the circumferential direction of the polishing roll. An arm driving part is mounted on a fixed frame, the rotating arm being mounted on the arm driving part, and the arm driving part drives the rotating arm to rotate in a circumferential direction.

A deburr tool has a flexible drive shaft and an expandable burr removal head. The expandable burr removal head is selectively collapsible and expandable. While collapsed, the burr removal head can navigate through the lumen of a non-straight tube, including across the abrupt right angle turn from an inlet tube section to an outlet tube section in an aircraft Piccolo tube. When expanded, the burr removal head engages the inner wall of the tube. The flexible drive shaft operatively connects the burr removal head to a prime move such that the prime mover drives rotation of the burr removal head while expanded. The rotating, expanded burr removal head removes burrs from inside the tube.