ASSESSMENT OF THE IMPACT OF TECHNOLOGICAL HEREDITY ON INDICATORS OF RELIABILITY, DURABILITY AND ENVIRONMENTAL SAFETY OF ELEMENTS OF GAS TRANSMISSION SYSTEMS

Modern gas transmission systems are power facilities based on a main pipeline, which is a continuous pipe, along which devices are placed that provide gas pumping at predetermined parameters. Unlike other linear structures, such as roads, railways, the main pipeline throughout the entire period of operation is in a complex stress state under the influence of the internal pressure of the pumped product and functions as a pressure vessel. The operational reliability, durability and environmental safety of gas transmission systems are ensured by various control devices and pipe fittings. The article discusses issues related to predicting the operation of pipe fittings during the operation of the gas transmission system, while ensuring the required reliability, durability and environmental safety. An analysis of the phenomena of technical heredity is given, with the help of which it is possible to determine the causes of deviations in the output parameters of pipe fittings in the process of their manufacture or repair. It has been proved that the main feature of technological heredity is the transfer of a certain technological property from the previous technological operation to subsequent ones, characterized by the transfer coefficient of technological heredity. An indispensable condition for the monotonicity of changes in the transmission coefficient of technological heredity in order to ensure the required quality of manufacture or repair of pipe fittings is revealed. The economic principle of predicting the quality of manufacturing or repair of products is proposed for use, a relationship is found between the initial and output technological properties of pipe fittings, a route is chosen to achieve the required quality of its manufacture or repair, including procurement and finishing technological operations.

Determination Transition Resistance of Cathode-Polarized Main Pipeline on Magnetometery Data

The article deals with the inverse problem of determining the transient resistance of the main pipeline insulating coating. For this, UAV measurements of the magnetic induction vector modulus of the magnetic field excited by the system of electrochemical cathodic protection of pipelines are used. The solution method is based on Tikhonov's method for finding the extremal of the regularizing functional. The developed algorithm is implemented in software. The results of computational experiments are presented.

Water Hammer Control Using Additional Branched HDPE Pipe

In pressurised pipeline systems, various water hammer events commonly occur. This phenomenon can cause extensive damage or even lead to a failure of the pumping system. The aim of this work is to experimentally re-examine the possibility of using an additional polymeric pipe, installed at the downstream end of the main pipeline, to control water hammer. A previous study on this topic investigated additional polymeric pipes connected to the hydraulic system with a short joint section of the same diameter as the main pipeline. In the current research, a different method of including an additional pipe was considered which involved connecting it with a pipe of a smaller diameter than the main pipeline. Three additional HDPE pipes, with different volumes, were investigated. The performance of the devices was studied for hydraulic transients induced by both rapid and slow, manual valve closures. Experimental results show that the additional polymeric pipe can provide significant pressure surge damping during rapid water hammer events. As the valve closing time lengthens, the influence of the additional pipe on the maximum pressure increase is reduced. The additional HDPE pipe does not provide notable protection against hydraulic transients induced by slow valve closure in terms of reducing the first pressure peak. No relationship between the volume of the additional pipe and the damping properties was noticed. The observed pressure oscillations were used to evaluate a one-dimensional numerical model, in which an additional pipe is described as a lumped parameter of the system. The viscoelastic properties of the device were included using the one element Kelvin–Voigt model. Transient flow equations were solved with the implicit method of characteristics. Calculation results demonstrate that this approach allows one to reasonably reproduce unsteady flow oscillations registered during experiments in terms of the maximum pressure increase and pressure wave oscillation period.

Сomparative analysis of economic efficiency application of milling excavator working equipment for pipeline undermining

Introduction. The use of pipeline transport for the movement of hydrocarbons and petroleum products is the main strategic system of Russia with a huge volume of cargo turnover. The share of pipeline transport in the freight turnover of the Russian transport system is over 48 %. Maintenance of the pipeline system is impossible without the use of mechanization and special equipment. So, to restore its working condition, various options for sets of machines are used.Implementation of the methodology. As a result of the research carried out, a set of machines was selected for performing the technological operations of the overhaul of a section of the steel main pipeline. The main technical and economic indicators are calculated, taking into account the efficiency and expediency of using a set of machines.Results. The economic efficiency of a set of machines, including a hydraulic excavator with a developed milling working equipment, the novelty of which is confirmed by patents for a useful model of the Russian Federation, has been determined.Discussion and conclusions. The directions of further research are the calculation and substantiation of the necessary operating parameters for the introduction into operation of the milling working equipment of a hydraulic excavator.

Design of an electron beam welding installation based on the existing equipment for connecting pipelines without using a vacuum

The article is aimed at solving the problem of connecting pipelines using electron beam welding. During the presented study, the analysis of the object of study - the main oil pipeline was carried out, during which the main shortcomings in the formed welded joints were identified. The authors also analyzed the methods of forming welded joints, which showed the advantages of electron-beam technology. The means of electron beam welding were selected: a generator, an electron beam gun. The electrical characteristics of the installation have been calculated, which make it possible to formulate the requirements for the purchased equipment. As a result, the authors have designed an installation for electron-beam welding of joints of the main pipeline elements, which makes it possible to form welded seams up to 400 mm deep and 1 mm wide.

On the assessment of the potential for extracting information on defects in the main pipeline by the method of radar analysis of natural oscillation frequency

The paper deals with the issue of diagnostics of main pipelines by the vibration method, exploring the influence of the formation of cracks in the walls of the pipeline on the change in the frequency characteristics of the pipeline. By analyzing the difference in the natural oscillation frequency of a pipe with a crack and without it, it is possible to assess the location of the defect with a certain accuracy. The issue of the possibility of reading the natural oscillations of the main pipeline from the surface of the soil located above the pipeline is also being studied.

Geolocation and diagnostics of trunk pipelines using an active acoustic sensor

The article discusses the issue of determining the location of the main pipeline to identify the deviation of its position from the design due to climatic factors. The possibility of using active sensors capable of operating both as diagnostic devices installed on the main pipeline and as a beacon is investigated, according to the signal of which it is possible to determine the location of this sensor with acceptable accuracy. The optimal operating frequencies are determined by mathematical modeling to ensure the maximum data transfer rate and the required signal-to-noise ratio. The simulation results show the possibility of assessing the attenuation of signals in the ground, as well as determining the limiting range of the method.

Equipment for Damping Hydraulic Shocks in Pressure Hydrotransport Facilities

Newly developed equipment for damping hydraulic shocks in pressure hydrotransport facilities is reviewed in this article. This equipment includes a discharge, safety diaphragm, as well as a flexible diaphragm, which is connected to the main pipeline at both different ends of the backpressure valve. A rupture disc is attached to it from below and load is attached from above by means of a rod, so that it can efficiently act during movement of hydraulic fluid in the central main pipeline, i.e. when the flow to be transported contains abrasive contaminant of solid material. The load represents a piston, which is rigidly connected to the flexible diaphragm and the rupture disc and creates an airproof space filled with viscous fluid. At the same time, the lower space is isolated from the main pipeline by a flexible separating element before the backpressure valve and the upper space is also isolated by a flexible separating element located after the back pressure valve.

Mathematical model of pressure distribution in a main pipeline during pumping with the use of drug reducing agents, taking into account their degradation

Путевая деградация противотурбулентных присадок (ПТП) может стать причиной изменения основных параметров режима магистрального трубопровода - давления и расхода - относительно установившихся значений и осложнить контроль их отклонений от нормативных показателей. При этом до настоящего момента отсутствовала методика расчета режимов перекачки при использовании ПТП с учетом деградации. Авторами была поставлена цель по разработке методики для математического описания распределения давления в трубопроводе с учетом путевой деградации присадки, а также при различных концентрациях ПТП. Для достижения указанной цели предлагается дополнить уравнение баланса напоров с учетом эмпирической зависимости эффективности присадки от длины трубопровода. При расчетах давления в промежуточных точках трассы предлагается использовать данные опытно-промышленных испытаний по изменению эффективности ПТП. Для иллюстрации применения методики рассматриваются примеры перекачки нефти и нефтепродуктов с добавлением присадок в различных концентрациях. На основании экспериментальных данных получена адекватная математическая модель снижения эффективности ПТП по длине магистрального трубопровода для различных концентраций вводимой присадки. Path degradation of drug reducing agents (DRA) can cause changes in the main mode parameters of the main pipeline; pressure and flow rate, relative to the stable values, and complicate the adjustment of their deviations from the standard indicators. At the same time, up until now there has been no methodology for calculating pumping modes when using DRA that takes degradation into account. The authors set a goal to develop a methodology to mathematically describe the pressure distribution in the pipeline, taking into account the path degradation of the agent, as well as the parameters at different DRA concentrations. To achieve this goal, it is proposed to supplement the equation of the pressure head balance with the empirical dependency of agent efficiency on the length of the pipeline. When calculating the pressure at intermediate points of the route, it is proposed to use the pilot run data on the change in the DRA efficiency. To illustrate the application of the methodology, examples of pumping oil and petroleum products with added agents in various concentrations are discussed. On the basis of the experimental data, an adequate mathematical model of the DRA efficiency reduction along the length of the main pipeline for different concentrations of introduced agent was obtained.