For severing where cutting debris or contamination of the interior flow line is a concern, there is a method called “Blue Line” cutting that effectively turns any pipe (1) into a “thin wall” suitable for roller wheel separation.
|By using a two-stage cutting method, you can sever pipe with a roller wheel that has a wall thickness well beyond the range of roller cutting.|
With Blue Line cutting, the work piece is first cut with conventional sever and bevel bits to a depth that leaves only a thin web of metal (2) and a wide groove. The area of the cut is cleaned of debris and the cutting bit is then switched to a roller wheel. The roller wheel is then positioned into the groove made by the cutting bit and brought into contact with the thin band of remaining unsevered metal (3). The roller wheel cut can now proceed until the pipe separates.