Method for forming an air gap pipe

A process and an apparatus for forming an air gap pipe are provided. Inner and outer pipes are bent or deformed into comparable configurations such that the inner pipe can be mounted within the outer pipe. The outer pipe then is split longitudinally by a preprogrammed cutting apparatus. The cutting of the outer pipe terminates just short of the complete longitudinal length of the pipe to facilitate rematching later in the process. The cutter includes a follower to trace the actual configuration of the pipe and thereby to offset differences from one pipe to the next. An array of clamps are provided to align the outer pipe halves relative to one another and to facilitate the reattachment.