Acoustic Emission Testing of the Column from Stainless Steel

Gomera, Victor; LLC “KINEF”; Russian Federation

Gomera, V.P.; LLC “KINEF”; Russia
Smirnov, A.D.; LLC “KINEF”; Russia
Tyupin, S.A.; LLC “KINEF”; Russia
Konstantin, V.Z.; Panatest; Russia
Legostaev, D.A.; SPA “Lencor”; Russia

ID: ECNDT-0510-2018
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The effectiveness of the acoustic emission (AE) method for testing of large-scale pressure vessels is shown. A case study is presented for detection of defects in the weld joints in a new column manufactured for use at petroleum refinery.
Due to irregularities in the welding procedure at manufacturing facility the column weld joints had internal defects, some of which were revealed at selective radiographic testing (RT) during acceptance control. This was the reason for conducting a complete NDT of welds of column shell. Herewith, the application of ultrasonic testing method was impossible due to features of column metal structure. RT method was used for testing.
As the result, there were revealed more than 30 weld joint areas containing internal cracks and non-metallic inclusions.
Revealed defects were repaired. AE method was the final testing step in column general inspection procedure. As the large scope of RT application allowed assuming with high probability that all possible defects are revealed, the main objective of AE testing was in the assessment of weld repair quality. The results of AE testing revealed no defects that tend to develop in repaired welds.
Additionally, as the result of AE testing there were detected 5 more areas containing AE sources characteristic for developing defects that were not revealed during RT.
The discussed example demonstrates such AE method advantages, as integral nature of testing, AE method independence of shape and orientation of defects and the possibility of substantial reduction of inspection time of large-scale structures. Due to features of application of different NDT methods the question on combination and sequence of their implementation for optimization of acceptance control of new equipment is discussed.
This paper also suggests an easy way of sensors mounting to the shell of structures made of stainless steel that works well in practice.