PSI - Issue 40

N.A. Makhutov et al. / Procedia Structural Integrity 40 (2022) 283–295

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N.A. Makhutov at al. / Structural Integrity Procedia 00 (2022) 00 – 000

b)

a)

Fig. 3. Pipeline design diagram during operation stage: a) – development of ellipticity ( , ); b) – development of concentrations near joints, defects with depth l , reduction of wall thickness δ min due to corrosion. 3. Technical diagnostics and condition monitoring of operating pipelines The modern Russian and foreign practice by Mazur et al. (2004) and Lisin et al. (2018) applicable to operating pipelines uses a wide range of control, examination and comprehensive technical diagnostics methods and means. Their main objective is to get direct experimental information on the main parameters of calculation expressions (1) and (2). The examined parameters in Russia include: - characteristics of mechanical properties of pipe steels at the given operating time - у ( ), ( ); - characteristics of geometric dimensions and forms of critical cross-sections - ( ), ( ), ( ) ; - parameters of defects' and cracks' dimensions – depth ( ), , location and form ( ), ( ); - weld parameters (height ℎ ); - minimum bending radius ( ) of pipeline axial line; - maximum ( ) and minimum ( ) pressure in a pipeline with consideration of hydrostatic pressure from elevation differences h along the pipeline route. The most complete information on the listed parameters of pipelines technical condition is received by Mahutov et al. (2021), Lisin et al. (2018) and Neganov et al. (2020) by during their diagnostics using pipeline pigs (Fig. 4). Ultrasonic and magnetic measurements during pig passing inside pipelines ( ) thick, with defect sizes ( ) and ( ) , diameter ( ) and radii of curvature ( ) in all planes are considered the source data for determination of critical pipeline sections, critical cross-sections at a given section and critical zones within a critical cross-section.