METHOD FOR PRODUCING PIPES TO BE CONNECTED IN A DOUBLE-WALL PIPING SYSTEM AND IMPLEMENTING MACHINE

摘要

The invention concerns a method for producing pipes to be connected in a double-wall piping system and a machine for implementing said method which consists in butt-jointed connection in a double wall piping system. Each pipe (1) comprises an inner tube (10) and an outer tube (20) in a relatively coaxial position providing between them an annular gap (31) up to a connection zone (2) at the pipe end where the outer tube is located longitudinally recessed from the inner tube. The method consists in deforming the outer tube (20) end part (3) by restricting its diameter until its contiguous end (presenting a weld seam closely adjusted with a provisional wedge) with the inner tube (10) for closing the annular gap (31), by operating concentrically with gradual pressure on its wall by means of a series of bars (42) annularly distributed around the connection zone (2) and by causing them to tilt over in a radial direction from a ring (43) fixed relatively to the outer tube whereon they are mounted articulated.