Registration Number
0223U005305,
(0122U001519)
, R & D reports
Title
Substantiation of the use of repair welding technologies for NPP pipelines in terms of ensuring strength and durability during further operation
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Розробка рекомендацій щодо застосування різних технологій в залежності від параметрів експлуатації трубопроводу та розмірів виявлених дефектів ерозійно-корозійного стоншення стінки
Head
Makhnenko Oleh V., Доктор технічних наук
Registration Date
19-12-2023
Organization
E. O. Paton Elektric Welding Institute National Academy of scinces of Ukraine
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Perform a set of calculation justifications for the use of repair welding technologies for NPP pipelines (secondary circuit and process pipelines) to ensure strength and durability during further operation, taking into account the experience of carrying out similar work for main pipelines.
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A general methodology for the numerical analysis of the state of pipeline elements with detected corrosion-erosion type defects in the process of repair by welding and during subsequent operational loading, a complex of mathematical models and means of their finite-element computer implementation for determining the current and residual stress-strain states of elements of pipeline systems has been developed NPPs during their repair welding. A set of methods for predicting the ultimate state of NPP process pipeline sections after their repair by welding or strengthening based on brittle and viscous failure criteria is proposed.
The peculiarities of the limit state of typical NPP pipelines with detected defects of local wall thinning after restoration by multi-pass surfacing were studied. It is shown that from the point of viscous failure, the bearing capacity is restored almost completely (the decrease in the pressure of failure in comparison with a defect-free pipe does not exceed 0.2 MPa). The resistance to brittle fracture of a repaired pipe is lower than that of a defect-free pipe and depends on the size of the postulated crack in the area of maximum residual tensile stresses. The use of multi-pass repair surfacing is an effective way to restore corroded process pipelines, but it requires careful non-destructive control of the presence of cracks in the area of the eliminated defect.
An analysis of the stress-strain state of a straight section of a pipeline with a defect of erosion and corrosion loss of metal under the action of internal pressure was carried out in order to evaluate the effectiveness of unloading the defective section in the case of use in the repair of a reinforcing structure such as a bandage or a welded coupling, an overlay patch. The effectiveness of unloading with reinforcing bandages and patches with a thickness equal to the thickness of the pipe wall for NPP pipelines of various sizes has been proven.
Product Description
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Bassistuk Nazar
Velikovanenko Olena А.
Kostenevich Olena S.
Milenin Oleksii S.
Makhnenko Oleg Volodyyrovych
Makhnenko Oleksiy O
Tuesday Nina I
Raisin Galina P
Savitskaya Olena M
Saprykin Galina Yu
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2023-12-19
