PSI - Issue 42

Mirjana Opačić et al. / Procedia Structural Integrity 42 (2022) 1185–1189 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1189

5

Discussion In the case study presented here, one can see that final decision on eventual actions to ensure safe operation of a pressure vessel with unacceptable defects detected in welded joints depends strongly on level of accuracy of method applied for NDT. As it turned out, application of PAUT has reduced risk level significantly, from very high to low, enabling further use of pressure vessel without any action. Not only dimensions, but equally important location of defects was decisive argument, since it turned out that defects are not present at the inner side of the vessel, making them not only smaller, but even more important, not practical for grinding and repair welding. Conclusions Based on the results presented here, one can conclude the following: • It is of utmost importance for structural integrity assessment to use not only conventional NDT, but also advanced methods, like PAUT. • Simple engineering tolls are efficient in structural integrity assessment of pressure vessels with defecets in welded joints • Risk-based analysis is useful to bridge the gap between engineers and managers, and can help significantly in decision making process. Acknowledgements This work is supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Contract No. 451-03-68/2022-14/200105 and. 451-03-68/2022-14/200213). We are also grateful to IMW Institute, Kragujevac, Serbia, for enabling PAUT and TODF measurement. References 1. Baldev Raj & T. Jayakumar: NDE methodologies for characterisation of defects, stresses and microstructures in pressure vessels and pipes, International Journal of Pressure Vessels and Piping, 73(2), 1997, pp 133-146. 10.1016/S0308-0161(97)00042-2 2. Sedmak, S., Grabulov, V., Momčilović, D., 2009, Chronology of lost structural integrity initiated from manufacturing defects in welded structures, Structural Integrity and Life, Vol. 9, No.1, pp.39-50. 3. A.M. Milovanović, T. Mijatović, Lj. Diković, Lj. Trumbulović, B. Drndarević: Structural Integrity Analysis of a Cracked Pressure Vessel, Structural Integrity and Life, Vol.21, No.3, 2021, pp. 285 – 289 4. L. Jeremić, B. Đorđević, I. Šapić, S.A. Sedmak, N. Milovanović: Manufacturing and Integrity of Ammonia Storage Tanks, Structu ral Integrity and Life, ISSN 1451-3749, Vol.20, No.2, 2020, pp. 123 – 129. 5. M. Aranđelović, L. Jeremić, B. Đorđević, S. A. Sedmak, M. Opačić: Integrity Assessment of Ammonia Storage Tank by Non-Destructive Testing, Structural integrity and life, Vol.21, No.3, 2021, pp. 295 – 300. 6. R. Jovičić, R. Prokić - Cvetković, O. Popović Non-Destructive Testing of Ferritic-Austenitic Welded Joints, Structural Integrity and Life, Vol. 5(3), 2005, pp 119 – 128 7. R. Becker, G. Dobmann, M. Kröning, H. Reiter, E. Schneider: Integration of NDT into life time management, International Journal of Pressure Vessels and Piping, 73(1), 1997, pp 11-17. 10.1016/S0308-0161(97)00028-8 8. H. Kurz, A. Jüngert, S. Dugan, G. Dobmann, C. Boller: Reliability Considerations of NDT by Probability of Detection (POD) Determination Using Ultrasound Phased Array, Engineering Failure Analysis, Vol. 35, 2013, pp 609-617. 10.1016/j.engfailanal.2013.06.008 9. Jeremic, L., Sedmak, A, Milovanović, N., Milošević, N., Assessment of structural integrity of pressure vessel for compressed air, Structural Integrity and Life, Vol. 21 (1), p. 3-6, (2021) 10. Golubović, T., Sedmak, A., Spasojević Brkić, V., Kirin, S., Rakonjac, I., Novel risk based assessment of pressure vessels int egrity. Technical Gazette 25, No. 3, p.803-807, (2018) 11. Vučetić, I. Kirin, S., Vučetić, T., Golubović, T., Sedmak, A., Risk Analysis in the Case of Air Storage Tank Failure at RHPP Bajina Bašta, Structural Integrity and Life, Vol. 18 (1), p. 3-6, (2018) 12. Kirin, S., Sedmak, A., Zaidi, R., Grbović, A., Šarkočević, Ž., Comparison of experimental, numerical and analytical risk assessment of oil drilling rig welded pipe based on fracture mechanics parameters, Engineering Failure Analysis, Volume 114, August 2020, Article number 104600 13. Zaidi, R., Sedmak, A., Kirin, S., Grbovic, A., Li, W., Lazic Vulicevic, L., Sarkocevic, Z., Risk assessment of oil drilling rig welded pipe based on structural integrity and life estimation, Engineering Failure Analysis, Volume 112, May 2020, Article number 104508 14. Newman, J. C., Raju, I. S. (1981) An empirical stress-intensity factor equation for the surface crack, Engineering Fracture Mechanics 15(1 – 2):185-192