When it is red, tap it toward the pipeline axis. Be careful not to burn it all at once. Start from 10mm or so, and burn for a short time. After it rises, it slowly pushes to both ends. Mainly the red part will rise, and the non-red part will basically not rise. There is no bending, or even if it is corrected, the tube hole in the middle will bend. After drilling, remove an irregular end, reaming again, and check whether the original pipe hole deviates into the pipe wall.

The job of a senior technician.