JOURNAL OF HYDROCARBON POWER ENGINEERING <p>111</p> en-US <p>Copyright Notice</p> (Mykhailo Myslyuk) Fri, 03 Jul 2020 00:00:00 +0300 OJS 60 Interference of torsion waves in the underground pipeline caused by the movement of the damaged foundation <p>In this article, we study the strength of underground pipelines, which are operated in difficult mining and geological<br>conditions in area full of tectonic faults. In such seismically active areas, in addition to the pressure load of the transported<br>product, the pipe is subjected to additional effects from the movements of the damaged foundation. When the movements are&nbsp; transient,a dynamic analysis of the behavior of structures must be carried out. The aim of the study is to develop a model to describe the non-stationary process of deformation of the pipeline on the damaged foundation, caused by the sudden mutual reversal of several fragments of the base around the axis of the pipe. The dynamics of the pipeline was investigated in a linear setting, modeling it with an infinite tubular rod. We consider blocks of a basis to be absolutely rigid; the behavior of a thin layer of soil backfill is described with the help of Winkler's hypothesis. The kinematics of mutual rotations of the base fragments is given by discontinuous functions from the axial coordinate. The strength of the pipeline is assessed by summing the standard and non-standard stresses, while the pipe is considered a torque-free shell. This approach makes it possible to assess the strength of the underground pipeline not by the external load from the soil, which is usually unknown, but by the kinematic parameters of the movements of the fault banks. An initial-boundary value problem for the differential equation of torsion with a discontinuous right-hand side has been formulated. Based on the analytical solution of the problem, the influence of the interference of torsion waves excited by sudden reversals of the foundation fragments around the axis of the pipe on the stress state of the pipeline under pressure has been studied. It has been established that the dynamic effects significantly depend on the structure of the breaking movements of the foundation and on the distance between the faults.</p> I. P. Shatskyi, M. I. Vaskovskyi, V. V. Perepichka Copyright (c) 2020 Ivan Shatskyi Fri, 03 Jul 2020 00:00:00 +0300 The influence of external and internal factors on stress corrosion cracking of low-alloyed pipe steel <p>The article presents investigation results of the regularities of stress corrosion cracking (SCC) of controllable rolling X70<br>pipeline steel under the influence of various factors: corrosion-active environment, potential, pre-accumulated stresses, periodic wetting, etc. Factors, acting in the conditions of the gas pipe mains operation, were simulated in the laboratory conditions and their influence on the SCC susceptibility of X70 pipe steel was investigated. It was found that in NS4 solution, potential shifting to the cathode area promotes the increasing of the SCC susceptibility of X70 steel. Under cathodic protection at potential equal to -1.0 V, the fracture characteristics change, a brittle component appears in the fracture, and the coefficient KS increases compared to the breaking of samples without cathodic potential. Under such a potential there may appear some differences in the SCC susceptibility of X70 steel, which have a minor structural features: steel with less contamination of non-metallic inclusions is less susceptible to brittle cracking. Accumulated cyclic stresses, periodic wetting, the presence of coatings with different transient resistance and the stress concentrator promote the increase of the degree of SCC susceptibility of X70 pipeline steel at a potential of -1.0 V.</p> L. I. Nyrkova Copyright (c) 2020 Roman Bishchak Mon, 02 Nov 2020 00:00:00 +0200 Technologies of cleaning and in-line inspection of gas mains <p>In-line inspection of pipe metal is an extremely important component of technical diagnostics of gas mains. The main<br>objective of inspection is determining the actual technical condition of gas pipeline and its equipment with subsequent repair of detected defects to ensure reliable operation of the facility. Untimely diagnostics and repair operations lead to higher failure rate and emergencies. Regular diagnostics makes it possible to determine effectively the technical condition and allows establishing the expediency of further operation and recommendations for the elimination of detected defects.</p> Yu. V. Banakhevych Copyright (c) 2020 Roman Bishchak Mon, 02 Nov 2020 00:00:00 +0200 Corrosion resistance of epoxy composite coatings for the transport industry in aggressive environments <p>Epoxy diane oligomer ED-20, 2,4-diaminoazobenzene-4'-carboxylic acid modifier, polyethylene polyamine hardener,<br>microdispersed particles of synthesized powder charge and a mixture of discrete fibers were used to form composite materials and protective coatings for the transport industry. The influence of aggressive media: oil, gasoline, sea water, acetone, NaOH (50 %), HCl (10 %) and H2SO4 (10 %) on the corrosion resistance of the developed composite materials with different content of ingredients was studied. The results of experimental studies suggest that the least swelling was observed for samples of composite containing components in the following ratio – modified binder: microdisperse filler in the form of a synthesized powder charge (Fe (70 %) + Ti (10 %) + TiC ) + Fe3C (5 %)) (d = 10–12 mm) : mixture of discrete fibers (modal (42 %), polyacrylic (38 %), polyamide (38 %)) – 100 : 0.05 : 0.10. The use of such a composite in the form of protective coatings of vehicles will ensure (if compared to the modified epoxy matrix) reduction of the permeability of aggressive media in: 1.5–1.7 times (when being used in oil and gasoline); 1.6–1.8 times (when being used in seawater, acetone and NaOH solution (50 %)); 3.0 and 2.5 times (when being used in solutions (10 %) of hydrochloric and sulfuric acids, respectively. Increased corrosion resistance compared to the matrix is caused by a decrease of the amount of polymer in the developed material and its increased cohesion strength, which increases the path of penetration of molecules of corrosive agents during their diffusion into the composite due to additives.</p> А. V. Buketov, O. M. Bezbakh, N. M. Buketova, T. I. Ivchenko, D. V. Zhytnyk, K. M. Klevtsov Copyright (c) 2020 Roman Bishchak Mon, 02 Nov 2020 00:00:00 +0200