Selecting welded, welded-and-drawn, or seamless tubing for an application is a complex process. Seamless Tubing offers increased corrosion resistance because it is 100% seam-free, without any longitudinal or orbital welds. Longitudinal welds present an opportunity for defect, which cannot be tolerated in critical applications.

To produce a welded tube, flat strip is roll-formed and joined with a longitudinal seam. The process can be done with laser alignment or tig welding. The weld area is dimensionally inconsistent with the strip and causes areas of stress concentration, particularly for tubes that are subjected to a high internal pressure. Furthermore, these crevices, which exist on both sides of the weld seam, create opportunities for corrosion and metallurgical contamination during heat treatment can lead to corrosion as residue becomes trapped.