Pipe Production Research Articles

Improvement of butt-fusion welding procedure and performance evaluation method for thick-walled bimodal polyethylene pipes

High-density polyethylene (HDPE) pipes have been continuously improved by the progress made by the resin industry and pipe manufacturers. Together with the advanced technology of welding equipment in terms of structure reliability and automations, HDPE pipes have been gradually applied to higher pressure level, bigger diameter, and thicker walls in operations which have become the preferred piping system for nuclear safety application in transporting cooling seawater. There are substantial differences in parameter settings when applying heat and force during different welding procedures, as well as the complicated evaluation methods for mechanical properties, which causes communication barriers between engineers and researchers. Thus, it is necessary to comprehensively study the welding procedures and evaluation methods to standardize the evaluation protocols in the industry. In this paper, based on the assumptions of temperature effect and molecular chain diffusion dynamics at the welding interface, the optimization of the welding procedure is proposed. Some well-established evaluation methods have been used for performance assessment and their feasibilities are discussed. The idea of creating crack along the weld interface is adopted as new method to evaluate the material ability of fracture resistance. Specimens with unilateral notch and weld interface crack are proposed and subjected for quasi-static axial tensile test. The fracture stress and fracture energy at the welding interface are used to differentiate the quality of the joint from different welding procedures. The fracture morphologies of the weld interface are analyzed. A complete picture is drawn for the mechanical fracture resistance of the weld interface. The method used in this paper can be corelated to the pipeline design conditions, therefore could be applied to the real-time engineering applications. Moreover, the evaluation method proposed in this paper is simple, reliable, and easy to implement.

ТЕХНОЛОГІЇ ОДЕРЖАННЯ ПОЛІМЕРНИХ КОМПОЗИЦІЙ ДЛЯ ВИГОТОВЛЕННЯ ПОГОНАЖНИХ ВИРОБІВ

The work is devoted to the characteristics of the technologies for obtaining a polymer composition for the manufacture of decorative products. Research is focused on the technology of manufacturing polymer composite material based on polyvinyl chloride for the production of rigid pipes, fittings, sidings, windows and doors, profiles, fences, railings, various devices, valves, housings of inspection lights, ventilation ducts, fans, heat exchange equipment, parts of chemical equipment , laboratory devices and other products. The paper describes the manufacturing technology of the PVC composition and investigates the important performance characteristics of the polymer melt. Three common technologies are presented, they are rolling, calendering and extrusion. The most common material for the manufacture of polymer. This composition is most often obtained by the extrusion method, so this section focuses on this technology in more detail resin products is a polyvinyl chloride composition. The stiffness of the polymer is characterized by the modulus of elasticity during bending. To determine this indicator, samples of polymer material without irradiation and with UV irradiation for a certain period of time were used. When the content of chalk in the recipe increases, the hardness increases. All compositions are characterized by approximately the same character - with exposure to six hours, the modulus of elasticity decreases, and with further exposure, it begins to gradually increase. The combination of а filler and a polymer is the most powerful for use in PVC compositions in the manufacture of decorative products.

ОСОБЕННОСТИ ПРОИЗВОДСТВА ПОЛИМЕРНЫХ ТРУБ МЕТОДОМ ЭКСТРУЗИИ

The features of the production of polymer pipes by extrusion are considered. The need for quality control of raw materials, as well as technological parameters at all stages of the process, has been identified

Analisis Kinerja Mesin CNC Milling 3 Axis pada Pembuatan Pipa Jet Oil

The study evaluated the performance of a 3-axis CNC milling machine in the production of jet oil pipes with a focus on achieving a high level of precision. Through variation of cutting parameters and feeding speed, the machine succeeded in reaching the industry standard for jet oil pipe production. Optimization of parameters improved production efficiency, demonstrated by results that achieved the desired precision tolerance. Cutting tool wear analysis provides insight into machine performance and possible repair actions. This research confirms the potential of 3 axis CNC milling machines in addressing the challenge of high-precision jet oil pipe production, contributing to the development of CNC Milling technology in the context of the oil and gas industry.

Thermal strengthening of seamless steel pipes grades 13KhFA for oil and gas industry

The present study focuses on grade 13KhFА steel alloyed with chromium and vanadium for the production of seamless pipes. The pipes were subjected to heat treatment throughout their body and along their entire length. They were fed individually into the furnace, end-to-end, consecutively. The heat treatment furnace was fueled by natural gas. Cooling of the pipes from the quenching temperature was achieved using water in a jet cooling multi-hole device (sprayer). This was followed by high self-tempering due to the heat retained after exiting the quenching furnace. Following quenching and high tempering, the structure of the 13KhFА steel on the surface of the pipe consisted of a mixture of ferrite and carbides with a granular carbide morphology (tempered sorbite). This structure enhances the corrosion resistance of the steel and provides an optimal combination of strength and toughness. The hardening temperature for seamless pipes made of 13KhFА steel was set within the range of 915–920 °C, while the tempering temperature was maintained at 720–730 °C. This careful selection of quenching and tempering temperatures within the specified limits makes it possible to obtain an improved structure of the 13KhFА steel. Keywords: pipe steel; thermal hardening; economically alloyed steel; regulatory standards; corrosion resistance.

Estimation of the repeatability and reproducibility of test results in determining the degree of cure of protective paint coatings using differential scanning calorimetry

The degree of curing of protective paint-and-varnish coatings for oil country tubular goods is a parameter characterizing the completeness of their polymerization, and allows drawing a conclusion about the final physicomechanical properties and the possibility of using the material under specific conditions. This parameter is considered decisive in conducting acceptance tests and incoming quality control of pipe products with plated protective epoxy coatings despite a low accuracy of the obtained results and the impact of various instrumental factors and methodological approaches. The authors have developed a methodology for determining the curing degree of coatings based on the procedures given in regulatory documents (CSA Z245.20 Series-18, GOST R ISO 21809-2), taking into account the analysis of factors affecting the results of determining the curing degree carried out in the previous work. According to the conducted studies, the rates of heating and cooling during the measurement process, the temperature test program (in particular, the presence and duration of isothermal exposures before heating cycles), and curve processing methods were corrected and selected in the proposed methodology. The aim of this work is the analysis of the precision of the developed method for determining the curing degree of protective coatings to confirm the high accuracy of the obtained values under observing the prescribed procedure. The analysis was carried out by statistical processing of the results obtained in comparative tests performed in four testing laboratories, and included calculation of the repeatability of the results by their standard deviation, reproducibility and assessment of the acceptability of these parameters. The developed procedure for determining the curing degree of protective coatings, from sampling to processing of DSC curves, showed good precision, which indicates the reproducibility and repeatability of the proposed method. The developed method can be used as a unified sequence for determining the curing degree of paints and varnishes used as protective coatings in different laboratories.

Real-time Welding Machine Status Recognition using Embedded Perceptron Color Classification Model

This paper aims to utilize the perceptron model in machine learning to achieve precise classification of the working status of welding machines by analyzing image data. We collected static images of welding and non-welding operations, extracted the R, G, B color values of the images, and labeled them accordingly (+1 for welding status, -1 for idle status). By employing the stochastic gradient descent method for training the perceptron model, we obtained the weights w and bias b of the model under the condition that all data points in the training set are correctly classified. The model's recognition accuracy was validated on the test set. Ultimately, we applied this model to the STM32f103zet6 microcontroller chip and successfully achieved real-time recognition of the welding machine's operational status during the welding process via a camera. Through testing, the classification accuracy reached 83.6%. Further optimization of classification criteria can be combined with relevant expert suggestions, providing a reference solution for monitoring and identifying the working status of welding machines in steel pipe production.

Bending of sheets and profiles on a four-roll machine for rocket bodies, pipe and frame products. Part 13

A theory of stamping is developed taking into account the anisotropy and hardening of the workpiece. The parameters of the strain-stress state of the workpiece are calculated using the example of bending a conical tube on a rolling machine or in a die. CAD/CAE modeling is used to study deformations, stresses and forces acting on the workpiece from rolls or die tools. The criteria for the formation of cracks, low accuracy and excessive springback of the part after processing are determined, and recommendations for their elimination are given. Keywords:stamping, workpiece, anisotropy, bending of a conical tube, rolling machine, die, CAD/CAE modeling dr_zharkov_v_a@mail.ru

A Study on the Residual Stress of Seam Pipe Cutting and Girth Welding

Seam pipes are easier to manufacture and cheaper than seamless pipes, and are widely used in the manufacture of pipe spools for marine plant facilities. The manufacturing and assembly of seam pipes involve welding and cutting. The localized heating and cooling that occur during these processes may change the existing residual stress and cause deformation. Uncontrolled deformation can accumulate as assembly errors at the next step, potentially delaying the entire process and causing economic losses. Therefore, characteristics of residual stress redistribution caused by cutting and girth welding of seam pipes need to be studied further. In this study, we performed thermo-mechanical analysis of the manufacturing, cutting, and girth welding processes of seam pipes using the commercial finite element analysis (FEA) software MSC Marc and analyzed the characteristics of residual stress. Furthermore, we measured the residual stress in each process using the hole drilling method, analyzed the characteristics of redistributed residual stress, and ensured reliability. Based on the results of FEA and measured residual stress redistribution, we can provide a basis for reasonable mitigation when performing structural integrity evaluation if there is a defect in the weld of the pipe.

Hygienic Analysis Of Microclimate Indicators At Polymer Production Enterprises

During the study, unfavorable microclimate indicators were assessed at the Jizzakh enterprise for the production of polymer products. The microclimate indicators at the enterprise for the hot period of the year (July, August) differed somewhat from comfortable indicators. The air temperature in the workshop for the production of consumer goods was above the maximum permissible dose from 0,80C to 6,90C. In the workshop for the production of polyethylene products films from 3,60C to 5,50C, in the workshop for the production of polyethylene pipes - from 3,80C to 4,60C, and at workplaces in the workshop for the production of polyethylene components from 3,80C to 4,60C

Annular expansion for enhanced orientation and mechanical properties of extruded amorphous PPESK/PES pipes

AbstractWith the discovery of deeper oil fields, conventional metal pumping pipes have been proven to be ineffective in meeting the requirements for deep well oil production due to their high weights and limited corrosion resistance. Therefore, in this study, a composite of Poly(phthalazinone ether sulfone ketone) (PPESK) and polyethersulfone (PES) was used to fabricate nonmetal pipes. To enhance the mechanical properties of the PPESK/PES pipes, a self‐designed annular expansion pipe extruder head was used. The circumferential burst stress and axial tensile strength of the PPESK/PES pipes subjected to 30° expansion were 73.0% and 48.9% higher than those of the unexpanded sample, respectively. When annular expansion was integrated into the extrusion of PPESK/PES/carbon fiber pipes, the axial tensile strength and circumferential burst stress were 45.9% and 88.8% higher than those of the unexpanded sample, respectively. Results of polarized infrared testing and metallographic microscopic examinations demonstrated that molecular chains present a regular orientation at a certain angle to the extrusion direction, under the effect of annular expansion extrusion. These findings highlight the efficiency of annular expansion in promoting the large‐scale production of pipes.

Mergers and Acquisitions in the Corporate Sector of the Russian Pipe Industry

The relevance of this study is determined by the significance of mergers and acquisitions as modern tools for expanded diversified growth, direct investment, production synergy, and overcoming the increasing risks of companies’ external environment. The work clarifies the content of mergers and acquisitions from the perspective of reorganization and business development, dominant and partial shareholder control. The high concentration of the Russian pipe industry is emphasized, which is due to the historical territorial concentration of key enterprises in the industry and modern trends of consolidation and movement towards a large-scale oligopoly in the domestic market. The mergers are based on signs of both vertical and horizontal integration, with a focus on creating a model of business units, each of which represents an enlarged production complex. The key driving force is recognized as the growing domestic demand for pipe products from enterprises in the oil and gas sector and municipal infrastructure in the context of the priorities of the national development strategy and the active state policy of project financing. A consistent combination of tight integration tools with technological cooperation programs with strategic counterparties has been proven. Signs of a merger were noted at the level of consolidation of internal assets of infrastructure divisions of large companies in the metallurgical industry.

Production of Adjustable Slotted Polymer Filter Pipes by Deformational Cutting

Production of Adjustable Slotted Polymer Filter Pipes by Deformational Cutting

Research regarding oxygen content reduction in steels

Actual paperwork reflects obtained results of technological analyse of reducing oxygen content in steel for pipe manufacturing, enterprised in a steel furnance equipped with a triple aggregate EAF-LF-VD. Oxygen content was measured during manufacturing process in Loading Furnance and Vacuum Degasing and has been analysed in comparison with several parameters. The results are presented using Matlab through regression surfaces and correlation equations and highlights the influence of analysed factors on oxygen content variation in steel.

ОБ ИСПОЛЬЗОВАНИИ ОТРАБОТАННЫХ ОПРАВОК ПРОКАТНОГО СТАНА ДЛЯ ИЗГОТОВЛЕНИЯ МАТРИЧНЫХ КОЛЕЦ ПРЕССОВЫХ ЛИНИЙ ТПЦ-2 В УСЛОВИЯХ АО «ВТЗ»

The possibility of using secondary raw materials from waste mandrels of the continuous TPA mill 159-426 mm of the pipe rolling shop TPP-3 in the manufacture of matrix rings (matrices) for the press lines of the pipe-pressing shop TPP-2 of VTZ «JSC» has been confirmed. The approach used allows us to reduce costs, and the development of the metal structure with subsequent heat treatment increases hardness and further increases the durability of pressing tools for pipe production.

RETRACTED: Enhancing desalination efficiency using waste heat from household air conditioning: A heat pipe-assisted HDH system performance analysis

This study presents an experimental exploration of a desalination system that produces freshwater from saltwater using a novel heat pipe-assisted humidification-dehumidification (HDH) process. The system utilizes waste heat recovered from residential air conditioners that use vapour compression refrigeration systems. The study focuses on the mass and heat transfer within the system's components, with performance evaluations conducted at three different air conditioning temperatures (19 °C, 20 °C, and 21 °C). The experiments highlight the freshwater production of the R32 heat pipe over the R134a and R600a heat pipes. The study estimates the system's cost-effectiveness at $0.0085/L, emphasizing its economic viability. Preheating resulted in significant improvements in freshwater yield, ranging from 43.33 % to 51.5 %, at temperatures of 21 °C and 20 °C, respectively. The Gain Output Ratio (GOR) doubled from 0.75 to 1.52, indicating a more energy-efficient process with significant improvements in the effectiveness of humidification and dehumidification. The pH levels improved from 8.32 to 7.07, representing a 15 % reduction and falling within the WHO-recommended range of 6.5–8.5. Electrical Conductivity (EC) shows a notable reduction from 62,720 to 826.1 micromhos/cm, representing a 98.68 % reduction, and well below the permissible limit of 1500 micromhos/cm. Total Dissolved Solids (TDS) also experienced a drop from 31,777 to 413.1 ppm, representing a 98.7 % reduction, and falls under the WHO guideline of <600 ppm for drinking water. The experiments prove that the use of waste heat from household air conditioners for sustainable freshwater production through the HDH desalination method, with the added efficiency benefits of heat pipe.

Optimization of an Air Conditioning Pipes Production Line for the Automotive Industry—A Case Study

Optimization of an Air Conditioning Pipes Production Line for the Automotive Industry—A Case Study

The role of natural sorbents and piping production waste in the treatment of acid iron-containing waste water

In this article, we consider the sorption purification of production wastewater from pipe industry enterprises. We have presented and studied the potential sorbents from among natural materials and from piping production waste. The authors of this paper have studied the sorption capacity of the materials under consideration with regard to heavy metals from highly acidic iron-containing wastewater both in static and dynamic modes. The static-mode research has been conducted for various temperatures: 10°С, 20°С and 30°С. In the dynamic conditions, the filtrate flow rate equaled 0.3, 0.6 and 1.2 l/h. The authors have proven that a number of the examined materials can be used as sorbents or constituting elements of composite sorbents for the technology of wastewater treatment at pipe industry enterprises.

State of production and quality control of metal pipeline connecting parts

The needs of the oil and gas industry for high-quality pipe products and pipeline connecting parts determined the relevance of the study. The main goal is to evaluate the dynamics of the production of pipeline parts at the Ural enterprise and the results of quality control of pipeline connecting parts in the enterprise’s laboratory. The enterprise observed an increase in the production of pipeline connecting parts in tons from 4415 tons in 2018 to 5081 tons in 2022, the share of the main products - bends - ranged from 85.9% to 88.7%, respectively. The quality indicators of twelve batches of steeply curved bends with a standard size of 325×8.0 mm are summarized. The quality control of bends is carried out in a certified laboratory of physical and mechanical testing and non-destructive testing of the enterprise. According to the control results, the mechanical and geometric properties met the requirements of GOST 17380-2001, some variability in the mechanical characteristics may be associated with fluctuations in the chemical composition of batches of pipe blanks, as well as changes in the structure and properties of the metal during the production of finished products.

APPLICATION OF MACHINE LEARNING FOR RECOGNIZING SURFACE WELDING DEFECTS IN VIDEO SEQUENCES

The paper offers a solution to the problem of detecting and recognizing surface defects in welded joints that appear during tungsten inert gas welding of metal edges. This problem belongs to the machine vision. Welding of stainless-steel edges is carried out automatically on the pipe production line. Therefore, frames of video sequences are investigated. Images of some welding defects are shown in the paper. An algorithm proposed by the authors is used to detect welding defects in the video sequence frames, the efficiency of which has been confirmed experimentally. The problem solution of welding defects recognition is based on the use of traditional machine learning methods: support vector machine and artificial neural network. To build classification models, a labeled dataset containing automatically extracted texture features from the areas of welding defects detected in the video sequences was created. An analysis was performed to identify the strength of the correlation of texture features between each other and the dependent variable in the dataset for dimensionality reduction of the feature vector. The models were trained and tested on datasets with different numbers of features. The quality of the classification models was evaluated based on the accuracy metric values. The best results were achieved by the classifier built using the support vector machine with a chi-square kernel on a training sample with two features. The build models allow automatic recognition of such welding defects as lack of fusion and metal oxidation. The computational experiments with real video sequences obtained with a digital camera confirmed the possibility of using the proposed solution for recognizing surface welding defects in the process of manufacturing stainless steel pipes.