Metal Pipes Research Articles

In‐Pipe Maintenance Robot Using Spray‐In‐Place Pipe Technique for Long‐Distance and Complex Pipe Environment

ABSTRACTConventional pipe rehabilitation technologies are not the most sustainable solution for the utility industry because of various drawbacks, such as time consumption, disturbance to operations, society, and traffic, and the production of waste material. However, aged underground metal pipes are affected by natural forces. Trenchless rehabilitation technologies have been introduced for the treatment and renovation of aged pipes to ensure that utilities are safe and durable from an economic perspective. This paper proposes a portable and automatic robotic solution for a trenchless spray‐in‐place pipe approach for small underground pipelines. This approach shortens the duration of the rehabilitation operation from approximately a week to < 5 h. The robot delivered and monitored a protective well‐mixed urethane coating with plural components accurately using rotary mixing and spraying with a low‐pressure and safer configuration (< 0.8 MPa). The robot exhibited superior capacities in complicated pipe environments for turning into 90° elbows and 6‐in. (150 mm), 8‐in. (200 mm), and 10‐in. (250 mm) pipelines. An automated robot was deployed and rehabilitated at various underground and on‐ground pipe sites. The spray performance was validated using tensile tests. This robot can be applied to any pipeline system and can be developed for other in‐pipe robotic construction and renovation approaches.

The Evolution of the Land Drilling Rig

_ The earliest land rigs used materials like bamboo and iron and were powered by animals such as horses or oxen. These rigs used percussive drilling to create the bore, repeatedly raising and dropping heavy iron bits—effective but slow. By the time Edwin Drake was drilling the Titusville well in 1859, steam engines had been introduced to help power now metal pipe down into the Earth’s crust. By the 1950s, steam-powered rigs gave way to diesel engines. The 1960s would see the advent of self-elevating rigs—the transition from derricks to mast. During the 1970s, electrical power using on-site generators was introduced to drive systems on the rig, and the advent of new downhole tools would allow drillers to directionally drill while maintaining rotation. In the mid-1980s, the first steerable drilling system was introduced. Soon, the evolution would move from the drill floor and downhole into the doghouse (driller’s cabin). Gone were the mechanical hand brakes and foot pedal systems, replaced by touchscreens and joysticks. The land rig has come a long way. Hoisting capability and rig-up requirements were key drivers in the design of older units rather than an ability to store materials and move. Older rig-floor configurations were modified to accommodate pipe-handling equipment instead of designed to integrate pipe-handling equipment. These units were not driven by location sizes nor multiwell pad capabilities. Most of this would change with the coming of the new millennia, and by 2010, it would seem like new innovations would be integrated into land rig design every year—from larger variable skid systems allowing for pad and batch drilling to app-based automation driving efficiency and safety profile. Topdrives? Onshore? Most of what drove innovation in land rigs can be traced back to development in the offshore sector. Much of what would become standard technology on land had its roots offshore, starting with one of the most important technology transfers of the 1990s—topdrives.

ВЛИЯНИЕ СКОРОСТИ ПРЕССОВАНИЯ НА МИКРОСТРУКТУРУ МЕТАЛЛА ТРУБ ИЗ СТАЛИ 08Х18Н10Т

The study of the microstructure of the metal of pipes with dimension Ø108×9,0 mm made of steel 08X18H10T, pressing of which was carried out at different speeds, is presented. It was determined that the pipe pressed at a lower speed contains more δ-ferrite and has a smaller austenite grain size.

Performance of a RuCs/MgO catalyst coated on additive manufactured support structures via electrophoretic deposition for ammonia synthesis

This work investigates the electrophoretic deposition of a catalytic coating on so-called fluid guiding elements (FGE) with a ruthenium-based catalyst for use in ammonia synthesis reactors. FGE are additive manufactured metallic pipe inserts that have shown to enhance the heat transfer compared to empty pipes by dividing the fluid flow and alternately guiding the partial flows to the wall. Consequently, they could improve the performance of temperature sensitive structured catalytic systems. To be able to demonstrate the degree of process intensification, the required steps to enable the deposition of a reference catalyst for ammonia synthesis are developed. Further, the distribution of catalytically active compounds is characterized. The catalytic activity is assessed in a plug flow reactor under pressures up to 5MPa and compared against a fixed bed from the same batch. The expected activity from the reference catalyst is calculated by a kinetic rate expression. The coating process does not affect catalytic activity, but a steady deactivation and high sensitivity to feed gas impurities are observed. Possible mechanisms for the deactivation are examined and discussed.

Enhancing Latent Heat Energy Storage With Heat Pipe–Metal Foam: An Experimental Investigation of the Partial Filling Strategy

ABSTRACTMelting and solidification of a phase change material (PCM) is investigated experimentally by applying a partial filling strategy to the hybrid enhancement of heat pipe–metal foam (HP‐MF) in a vertical cylinder. HP‐MF enhancement can improve the heat transfer capacity of the PCM system as it combines HP's efficient heat transfer capacity with MF's highly effective thermal conductivity capability. The experimental results demonstrate that the partial filling strategy in the melting and solidification of HP‐MF PCM can be optimized for effective MF utilization in the HP‐MF PCM system. A filling ratio of 83% of MF in HP‐MF PCM shows almost identical total melting and solidification along with a temperature distribution to that of an HP‐MF PCM (95% porosity, 20 pore density [PPI]). It is plausible to conclude that the removal of 33% or less mass had no significant effect on the overall melting process of HP‐MF PCM. It should be noted that the HP‐MF PCM system's HP heat transfer efficiency significantly decreased during the melting process when the MF filling ratio was 37.5% and 12.5%.

Flexible All-Inorganic Thermoelectric Yarns.

Achieving both formability and functionality in thermoelectric materials remains a significant challenge due to their inherent brittleness. Previous approaches, such as polymer infiltration, often compromise thermoelectric efficiency, underscoring the need for flexible, all-inorganic alternatives. This study demonstrates that the extreme brittleness of thermoelectric bismuth telluride (Bi2Te3) bulk compounds can be overcome by harnessing the nanoscale flexibility of Bi2Te3 nanoribbons and twisting them into a yarn structure. The resulting Bi2Te3 yarn, with a Seebeck coefficient of -126.6µVK-1, exhibits remarkable deformability, enduring extreme bending curvatures (down to 0.5mm-1) and tensile strains of ≈5% through over 1000 cycles without significant resistance change. This breakthrough allows the yarn to be seamlessly integrated into various applications-wound around metallic pipes, embedded within life jackets, or woven into garments-demonstrating unprecedented adaptability and durability. Moreover, a simple 4-pair thermoelectric generator comprising Bi2Te3 yarns and metallic wires generates a maximum output voltage of 67.4mV, substantiating the effectiveness of thermoelectric yarns in waste heat harvesting. These advances not only challenge the traditional limitations posed by the brittleness of thermoelectric materials but also open new avenues for their application in wearable and structural electronics.

Ensuring the reliability of automated pulse electric spark control of pipe coatings in in-line production

The issues of ensuring the reliability of automated electric spark testing of the continuity of dielectric coatings on metal pipes with diameters up to 1.5 meters in the context of in-line manufacturing are addressed. A simulation of the “high-voltage pulse source – electrode – dielectric coating – metal substrate” system has been conducted. Experimental studies have been conducted to evaluate the load capacity and voltage stability of the Corona 2.2 holiday detector using an improved generator at high capacitive loads.

Design and Calculation of Products from Composite Materials Using Software

This article analyzes six types of composite pipes that are good replacements for corrosive steel and metal pipes for oil, gas, and water. The analysis of the six samples of composite pipes was done using the software program Hoffman Engineering, which is intended for the design and calculation of various types of products made of composite materials. For the analysis of the six composite pipes, the same diameter and the same length were taken, and variable parameters are: the type of material from which the composite pipes are made (carbon/epoxy, carbon-glass/epoxy and glass/epoxy), and the angle of winding of the fibers (10º and 90º degrees). Using the Hoffman Engineering software package, an analysis of the durability of the six differently designed composite pipes at high internal pressure was performed. The same conclusion was obtained from all analyses: the high internal pressure resistance of composite pipes is highly dependent on the fiber winding angle and the type of fibers used. Composite pipes obtained with a fiber winding angle of 90º have twice the internal pressure resistance compared to composite pipes obtained with a fiber winding angle of 10º. Composite pipes based on carbon fibers have the highest resistance to internal pressure, then composite pipes based on hybrid materials (glass and carbon fibers) and finally composite pipes based on glass fibers. Finally, a comparison was made with the obtained laboratory results for the same composite pipes. The same conclusion was obtained from all analyses: the high internal pressure resistance of composite pipes is highly dependent on the fiber winding angle and the type of fibers used. The composite pipes obtained by this process are durable and resistant to very high pressures.

Assessment of the synergy of hydrophobicity and thermal conductivity in epoxy/graphite oxide composite coatings

AbstractIn various industrial applications, especially within the internal pipes of heat exchanger devices, there is a crucial need for surface coatings that offer both superhydrophobic properties and high thermal conductivity. Achieving the balance between these two characteristics is essential for optimizing heat transfer performance along metal pipe walls and mitigating the formation of water droplets on the surface. This research focuses on the development of polymer composite coatings to address these dual requirements, providing protection against humid environments, resistance to dew formation, and simultaneous enhancement of thermal conductivity. The key challenge lies in selecting a coating type that provides low surface energy and polarity, thereby achieving the desired hydrophobic properties while also maintaining adequate thermal conductivity. This study formulates polymer composite coatings utilizing laser‐modified epoxy resin and strategically integrates graphite oxide particles. These graphite particles undergo modification through oxidation to enhance compatibility with epoxy. In conjunction with graphite oxide modification, the resulting laser‐modified coatings exhibit super‐hydrophobic characteristics with an enhanced water contact angle of 162° and a low contact angle hysteresis (<5°). Furthermore, the epoxy/graphite oxide composite coatings demonstrate improved thermal conductivity, marking a significant 261% increase compared to pure epoxy, elevating it from .234 to .846 W/mK.

Non-contact and non-invasive water level measurement outside metal pipes with electromagnetic acoustic resonance

Accurate measurements of water levels within metal pipes are vital, particularly in environments where thick-walled pipes serve as critical components, such as in nuclear facilities. Measuring water levels in pipes becomes more difficult under high temperatures and pressures. In response to this need, a method involving electromagnetic acoustic measurement is proposed. This method begins with a transducer emitting a high-frequency pulse designed for precise measurements of wall thickness, then calculates the resonance frequency using the time intervals between echoes. Finally, the transducer emits an excitation signal at the fundamental resonance frequency to measure the water level. At low water levels, the measurement is conducted by manually scanning along the pipes, utilizing varying energy losses. At high water levels, the resonance echo method is employed. Numerical simulations have demonstrated that this approach effectively improves signal amplitude, thereby ensuring the robustness of the measurement. Experimental results also demonstrated that the proposed method boosted the echo signal-to-noise ratio to approximately 15 dB. Additionally, it successfully detected water levels in both aluminum and stainless-steel pipes. Therefore, it is considered to be a highly efficient non-contact and non-invasive method to measure liquid levels in metal pipes, and it has proved to hold significant potential for engineering applications.

Investigation of High-Temperature Oxidation Behavior of Additive Manufactured CoCrMo Alloy for Mandrel Manufacturing.

The cyclic oxidation behavior of an additive manufactured CoCrMo alloy with 0.14 wt.% C was investigated at 914 °C for 32 cycles, each lasting 10 h, resulting in a total exposure time of 320 h. The oxidation rate was assessed for mass gain after finishing each 40 h oxidation cycle. It was experimentally determined that the oxidative process at 914 °C of this CoCrMo alloy follows a parabolic law, with the process being fast at the beginning and slowing down after the first 40 h. The microstructural analysis revealed that in the as-printed state, the phases developed were primarily the γ matrix and minor traces of ε phase. The oxidative process ensured an increase in the ε phase and precipitation of carbides which produced a 12% increase in the material's hardness after the first 40 h of exposure at 914 °C. The oxidation process led to the development of an oxide scale comprising a dense Cr2O3 layer and a porous layer of CoCr2O4 spinel, the latter spalling after the 240 h of exposure. Despite this spallation, the oxide scale continued to develop in the presence of O, Cr, and Co. The experimental analysis provided valuable insights regarding the material's behavior under prolonged exposure at high temperature in air, demonstrating its suitability as a candidate for additive manufactured mandrels used for bending metallic pipe fitting elbows.

Leakage Quantification in Metallic Pipes under Different Corrosion Exposure Times

The combined effects of aqueous corrosion, stress factors, and seeded cracks on leakage in cast iron pipes have not been thoroughly examined due to the complexity and difficulty in predicting their interactions. This study seeks to address this gap by investigating the interdependencies between corrosion, stress, and cracks in cast iron pipes to optimise the material selection and design in corrosive environments. Leakage experiments were conducted under simulated localised corrosive conditions and internal pressure, revealing that leakage increased from 0 to 25 mL with crack sizes of 0.5 mm, 0.8 mm, 1 mm, and 1.2 mm, along with corrosion times of 0, 120, 160, and 200 h, and varying stress levels. An empirical model was developed using a curve-fitting approach to map the relationships among corrosion time, crack propagation, and leakage amount. The results demonstrate that the interaction between corrosion, stress, and crack propagation was complex and nonlinear, and the leakage amount increased from 0.7 to 0.10 mm every 15 min, as evidenced by SEM microstructure images and empirical data.

Effect of contact blast loading on the plastic deformation forming ability of large steel pipes

Plastic deformation forming with metal pipe blanks by contact blast loading inside pipes is an interesting moldless forming technique, also a complex and error-prone process. Some advantages are very characteristic of this forming technique such as no cost of mold, tooling and low energy consumption, no complicated control equipment compared to other forming techniques such as casting, rolling, tube hydrostatic forming, bending – welding. Up to now, the calculation and design of this forming technique mainly use some existing reference empirical formulas, so the experimental results are only suitable in the range of small pipe diameters, and still there are significant deviations for larger pipe diameters. In order to increase the predictability and accuracy of forming process by contact blast loading inside large pipes, this paper presents a study on the influence of the mass of highly explosive material – TNT to the forming ability of large steel pipes from API-5LX-42 mild steel materials by modern 3D numerical simulation – using Abaqus/Cae software. Four output criteria with maximum values are used to evaluate the efficiency of this forming process, including maximum diameter of the blast zone (Dmax£2D0), Von Mises stress (Smax£UTS), Hoop plastic strain component (PE22max£1), and Pipe wall thinning rate (eT-max£60 %). The results of this research on the plastic deformation forming process using numerical simulation can be used for the next experimental step to evaluate the difference between simulation and experiment, as well as use this data in the calculation and design of pipe products with circular or square cross-sections to save both time and money of trial and error before application in actual manufacturing

Novel computational model for the failure analysis of composite pipes under bending

This study presents a novel computational model to investigate the bending behaviour of thin- and thick-walled composite pipes made from fully bonded fibre-reinforced thermoplastic composite materials. The primary objective is to analyse the stress state and predict potential failure modes of these pipes, which have gained significant interest in the oil and gas industry due to their advantageous properties. The developed model is validated through comparisons with finite element analysis and published results, demonstrating its accuracy and adaptability. Utilising the validated computational model, safety zones for composite pipes with various stacking sequences are established, providing valuable insights into the optimal design of composite pipes under bending loads. Furthermore, the method is employed to determine the maximum bending moment and critical bendable radius of the pipe, revealing the direct correlation between maximum bending moment and bending stiffness, independent of the bending radius. The findings of this study offer practical guidance for the design and optimisation of composite pipes in the oil and gas industry, promoting their adoption as a viable alternative to traditional metal pipes. The developed computational model serves as an efficient and reliable tool for engineers to make informed decisions in the design and selection of advanced composite materials for pipe applications, enabling the optimisation of pipe performance under various bending load scenarios.

RESISTANCE OF FERRITE-PERLITE STEEL TUBING BRANCH PIPE METAL TO DESTRUCTION IN HYDROGEN SULFIDE MEDIUM

This paper discusses the problems of resistance of the metal of the tubing branch pipe (tubing) to the process of its destruction in a medium containing hydrogen sulfide and when exposed to external forces. A 73х73 tubing nozzle made of 38G2SFA steel was selected as the material for research. The tubing fragment was destroyed during production well operation. To establish the reasons for the failure of the tubing nozzle, a visual inspection was carried out, tests were performed to assess the hardness and mechanical properties, the microstructure and microtexture of the metal were analyzed using scanning electron microscopy (SEM) methods. To analyze the nature of the distribution of introduced defects, the mutual orientation of structural components and crystallographic texture, studies were carried out by the method electron backscatter diffraction (EBSD). Studies of the suspended branch pipe, which does not have chemical protection, showed that the cause of its destruction was hydrogen sulfide stress corrosion cracking (SSCC) as a result of hydrogen embrittlement and the action of external tensile forces exceeding the yield strength of the metal. It was established that as a result of the interaction of hydrogen sulfide of the distilled product with the metal of the branch pipe, hydrogen embrittlement of the material of the branch pipe occurred. The process of hydrogen embrittlement of the fragment was proved by detecting hydrogen blisters in the metal microstructure and establishing the process of coalescence of neighboring inclusions. In addition, the results of the test to measure the hardness of the metal along the wall thickness further supported the hypothesis of hydrogen embrittlement of the tubing. EBSD analysis showed that the threaded part of the branch pipe is characterized by a small size of structural elements and an increased density of introduced defects (geometrically necessary dislocations), which are a promising site for the deposition of molecular hydrogen. It is concluded that reaching the limit concentration of molecular hydrogen reduces the binding energy of metal atoms and this process initiates the formation of pores. It has been established that the development of cracks along large-angle grain boundaries is facilitated, and small-angle and coincidence site lattice (Σ3, Σ5, Σ11 and Σ13b) grain boundaries are active barriers to crack propagation. It has been shown that by optimizing the elemental composition of steel, controlling the microstructure, crystallographic texture, as well as the type and state of grain boundaries, new pipeline steels can be produced that are more resistant to SSCC.

Highly accelerated life testing (HALT): A review from a statistical perspective

AbstractDespite its use in one form or another for at least four decades, HALT and related techniques [e.g., highly accelerated‐stress screening (HASS) and stress audits (HASA)] are not well understood within the statistical community and remain controversial. This largely reflects a conflict in motivation between engineers, testing under harsh conditions to discover and eliminate failure modes, and statisticians, taking a more cautious approach to develop quantitative estimates of parameters such as mean time between failures (MTBF). This review article will clarify HALT concepts and methods and explain where it fits within the universe of methods that involve the application of accelerating factors to compress the time required to evaluate or enhance product reliability. A major distinction is between methods such as HALT, a high‐stress test‐analyze‐fix‐test iterative process directed at improving reliability by discovering and fixing weak points in a design, and quantitative accelerated life testing (QALT), whose goal is the estimation of product life for a fixed design. We discuss methods such as physics of failure that offer some hope of bridging the gap between the qualitative nature of HALT, and purely quantitative statistical methods. We present a variety of engineering applications of HALT including metal fatigue, piping and pressure vessels, structural damage, radiation damage, and rotating machinery. We also discuss potential synergies between HALT and QALT, such as rapid identification, through HALT, of failure modes requiring quantitative analysis. For further study, extensive references to the applicable literature are provided as well as an appendix that describes related methods.This article is categorized under: Statistical and Graphical Methods of Data Analysis > Reliability, Survivability, and Quality Control

Phased Array Ultrasonic Testing on Thick Glass Fiber Reinforced Thermoplastic Composite Pipe Implementing the Classical Time-Corrected Gain Method

Thermoplastic composite pipe is gaining popularity in the oil and gas and renewable energy industries as an alternative to traditional metal pipe mainly due to its capability of being spooled onto a reel and exceptional corrosion resistance properties. Despite its corrosion-proof nature, this material remains susceptible to various defects, such as delamination, fiber breakage, matrix degradation and deformation. This study employed the phased array ultrasonic testing technique with the implementation of the classical time-corrected gain method to compensate for the significant spatial signal attenuation beyond the first interface layer in the thick multi-layered thermoplastic composite pipe. Initially, the ultrasonic signals from the interface layers and back wall were detected with good signal-to-noise ratios. Subsequently, flat-bottom holes of varying depths, simulating one-sided delamination, were bored and the proposed method effectively identified ultrasonic signals from these holes, clearly distinguishing them from the background noise and interface layer signals. Finally, a defect deliberately fabricated within the composite laminate layers during the pipe manufacturing process was successfully identified. Subsequently, this fabricated defect was visualized in a three-dimensional representation using the X-ray computed tomography for a qualitative and quantitative comparison with the proposed ultrasonic method, showing a high level of agreement.

Leakage detection applied to the Da Hedong Reservoir dam (China) based on the flow-field fitting method

Detecting leakage in concrete gravity dams presents a formidable challenge. The flow-field fitting (FFF) method is used to identify leaks in China’s Da Hedong Reservoir dam. We develop vertical- and horizontal-gradient approaches based on the transmitted signal electrical field. A plastic frame is developed to allow the probe to measure horizontal gradients. We determine the exact location of leaks at the reservoir’s bottom and upstream face, respectively, assuming that current leakages are located in hydraulic leakage zones. Numerical experiments and water pressure tests reveal that the conductive silt layer beneath the reservoir can lower the response of the potential values at the leakage inlet, and the effect of the silt layer should be considered and not ignored when interpreting measured data. In addition, with regard to the principle of superposition, the contribution associated with metal pipes in the dam body can be roughly determined by subtracting it from the original potential field data, thereby aiding in locating leaks around the metal pipes. In addition, the FFF measurements from the reservoir’s bottom also confirm the position of existing faults in the substratum at the reservoir site. Last, the results of the FFF method are tested against supporting evidence, such as ground penetrating radar and water pressure tests. In conclusion, these independent data confirm the effectiveness of the FFF method for leakage localization in the concrete gravity dam.

Mechanical strength and low-velocity impact behavior of glass fiber reinforced filament wound pipes with different number of layers after hydrothermal aging

Composite pipe is preferred over metal and other materials for water supply, liquid chemical transport, and fuel and gas transport. This is because composite pipes are more corrosion resistant, have a high strength/density ratio, high stiffness/density ratio, and more durable than metal pipes. The properties of the composite pipes employed may differ based on the operating environment. Therefore, determining the properties of the composite pipe according to the working environment is extremely important for its lifespan. The thickness of the samples is increased in line with different needs (such as increased strength). Increasing the thickness of samples, especially those exposed to different environmental conditions, and investigating the changes that will occur in the physical and mechanical properties of the samples are another important situation. In this investigation, glass fiber (GFRP) reinforced epoxy composite pipes have been examined, which were manufactured using the filament winding method with different layers [±55°]. To determine their properties in different working environments, the GFRP composite pipes were subjected to hydrothermal aging in pure water at 80°C for several days (7, 14, 21, and 28). The changes in their mechanical properties under working conditions were determined through hoop tensile strength tests and low velocity impact tests applied at different energy levels. The experimental results show that the tangential stress values increased by 10.59% as the number of layers increased. As the aging time increased, the durability of the 6-layer composite pipe decreased by 17.69%. Furthermore, the ability of the aged pipes to withstand damage was evaluated, revealing that the aging process exacerbated the damage within the pipes.

Autonomous Robot On-Pipe Leak Detection

The research addresses the critical need for efficient and cost-effective pipe inspection methods in modern infrastructure, focusing on the maintenance of water and gas delivery systems. The objective is to improve defect detection and maintenance processes in pipes, reducing downtime and operational costs. The proposed method involves deploying pipe inspection robots, with an emphasis on on-pipe robots tailored for specific applications such as urban gas lines, small feeder pipes, and sewer systems. These robots are categorized into seven sub-types, including wheel-type, inchworm-style, AI-powered sewer inspection, caterpillar-style, and helical motion robots, each designed for unique inspection challenges. A newly developed versatile on-pipe inspection robot is highlighted for its ability to inspect a variety of plastic and metal pipes in both horizontal and vertical orientations. This robot features a body, foreleg system, rear leg system, and springs, enabling smooth navigation through pipes. The performance of this robot shows substantial improvements in inspection efficiency and accuracy, proving its effectiveness as a modern solution for infrastructure maintenance.