By: David Segletes and Dan Peters
One of the strengths of the Structural Integrity Associates (SI) team lies in the diversity of the skills and capabilities in the organization. Sure, SI can perform inspection, analysis, design, metallurgy, failure investigations, risk assessments, and project management, but one of the real values of working with SI is when all of those aspects are brought together to solve an issue.
Recently, a client approached SI after finding a through-wall flaw in an autoclave at the head-to-shell weld as indicated by a visible dye liquid penetrant examination (Figure 1). The autoclave was one of eight similar vessels used for processing the client’s product. Three of the autoclaves are identical in construction to the flawed autoclave and operate with similar process conditions. Remote visual examination by the client indicated that all four autoclaves had similar observations at the inside of the head-to-shell weld, but only one was leaking. The remaining four autoclaves are smaller and are used infrequently. The initial call from the client was for SI to provide emergent support for inspection of the three autoclaves identical to the leaking one to meet production demands. SI responded quickly and examined all four autoclaves using a manual phased array ultra-sonic technique (PAUT) from the exterior of the vessel. The manual PAUT examination provided excellent coverage of the weld region and visualization of the through wall flaw (Figure 2).