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) 000 – 000

Fig. 1. Laying territory of oil trunk pipeline "East Siberia - Pacific Ocean I"

Operating life of currently functioning pipelines varies from 0 to over 60 years. Operating pressure in pipelines is 2 - 6 MPa. Diameters of pipelines d vary in 450 – 1020 mm range, wall thickness δ – 8-28 mm. Pipelines are made of low-carbon low-alloy steels with yield strength σ y =240÷560 MPa and tensile strength σ u =420÷750 MPa. The main trunk pipeline systems of Russia include: "Surgut - Polotsk", "Nizhnevartovsk - Kurgan - Kuybyshev", "Ust-Balyk - Kurgan - Ufa - Almetyevsk", BTS (Baltic Pipeline System) oil pipeline systems, Druzhba, VSTO (East Siberia - Pacific Ocean), etc. 2. Basic and verification strength calculations during design and operation stages Foreign and Russian pipelines are designed by SNiP 2.05.06-85 (1986), ASME B31.4 -2019 (2019) and DIN 2470-1:1987-12 (2015) on the basis of deterministic calculations for static strength using allowable stresses by Mahutov et al. (2021) or ultimate resistances during greatest hoop stresses from pressure (Fig. 2-a).       , , , , u y y u k y u u y H m n n K K K                     (1) where у , – safety factors ( 1,2 ≤ у ≤ ≤ 2,5); , у − material reliability factors ( 1,3 ≤ у ≤ ≤ 1,55) ; m – service factor (0.6 ≤ m ≤0.9); n – load safety factor (1.1 ≤ n ≤ 1.15).