This work is aimed at assessing the stress-strain state of a gas pipeline section with different types of defects. The purpose of the calculations is to determine the reliability of the pressurized structure and to assess its serviceability in future operation. The paper presents an assessment of the “dent” type defects and a non-through surface fracture, which were obtained as a result of impact loading. The calculations were performed in the ANSYS mathematical modelling software package, which is a multipurpose package for solving complex physics and mechanics problems based on the finite element method. A model of the gas pipeline section was created in the vicinity of which the defect is located. Preliminary equivalent stresses at normal operation of the object were calculated in this section, as a result of which the place was found, which has the highest load at normal operation. In this zone, defects are applied programmatically. In the process of research, it is revealed that at given geometric parameters, the considered defects do not pose a threat to further operation of the object. The considered assessment method is well suited for objects of different complexity and size, so the scope of application is vast - from machine parts to huge structures.