There have been several catastrophic failures in the United States involving seam welded piping. Each of these failures involved pipe ruptures and resulted in significant damage to the utilities involved. These failures also have resulted in deaths and personal injuries.
Seam welded piping for installation in critical power plant piping systems has been produced since the early 1940’s by about ten different manufacturers of this pipe, including M. W. Kellogg, Grinnell and ITT Grinnell, Tube Turns, National Annealing Box, Taylor Forge, Teledyne-Irby, and others.
In addition, elbows and other fittings for installation into the same piping systems have also been produced as clam shells by seam welding two half sections together. Failures resulting in steam leaks have also occurred in these types of seam welded fittings.
The catastrophic and leak-type failures that have developed in critical piping systems are associated primarily with materials engineering considerations.
Some of the catastrophic failures that have occurred actually developed at low-stress locations in the hot reheat and main steam piping systems involved. In every instance, the failure analyses confirmed that the problems were associated with the piping materials, including the manufacture of the piping, the fabrication of the piping, the procedures used in seam welding of the piping, the effects of preheat and post-heat treatments of the piping, and the erection of the piping. In addition, the effects of the service environments, particularly involving service temperatures, have also, to some degree, affected the conditions and severity of the failures that have occurred.