PSI - Issue 81

Ivan Shatskyi et al. / Procedia Structural Integrity 81 (2026) 240–243

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so the asymptotic formulas lose their validity, leading to an unjustified increase in the limiting pressure, as seen in case 3. Critical pressure 4  p calculated using coating strength criterion visibly does not change in the chosen range of defect length, but also has a descending character, so its minimal value 0.34MPa 4,min   p is reached at the limit of the results` validity at 20  l mm. Comparing the obtained results, we see that the weakest element of the repaired pipeline is the bandage with the lowest values of the limiting pressure in the entire range of the defect length change. However, even for minimal value 0.34MPa 4,min   p , the structural integrity is ensured for low-pressure pipeline networks with an operating pressure of 0.1MPa  p . 4. 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