Abstract: An isolation and protection device is suitable for being inserted and deployed inside tubing, in order, in particular, to collect swarf and foreign bodies during work on tubing which must be kept under a controlled gas atmosphere, or to act as a flow plug or as a heat shield.

Abstract: The method comprises the steps of: digging out a continuous groove (13) in the wall of the tubing at the location of the tapping point to be made, said groove being slightly shallower than the thickness of the wall, thereby leaving a membrane (14) of metal at the bottom of the groove between the inside of the tubing and the outside atmosphere; placing a sealed isolation unit on the tubing, said unit covering a wide area which is at least equal to the area delimited by the groove; breaking the metal membrane so as to make an opening in the wall of the tubing; removing the cut out portion of the wall; welding on a blind tail pipe; and removing the sealed isolation unit. The invention also provides a groove-digging device, and a membrane-breaking punch device (600).