Bob Browne: About the Author
ERA Technology

For reason of economy, the hot reheat pipework in many US power plants is fabricated from seam-welded low chrome-moly carbon steel spools. Unlike girth butt welds, where the critical weldment microstructures can off-load stress to the stronger parent material, seam welds are subject to the full pressure hoop stress. A number of failures have occurred, some of which have been evidenced by fast fracture over extended lengths of the seam weld with a massive and violent steam release.