Failure Analysis of Weld Repaired Industrial Valve Castings

Industrial valve castings are complicated, critical constructs that often require welding repair during manufacture or after service degradation. Welding and machining of these components is difficult, especially on complex interior passages and sealing features. Improper welding repairs can result in rapid, unexpected failure by a variety of mechanisms including fatigue, stress corrosion cracking, erosion, erosion corrosion, flow assisted corrosion, and reheat cracking. This presentation summarizes and illustrates many of the particular features and concerns regarding failure analysis of weld-repaired valves.