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Intelligent pipeline isolation tools (IPITs) are widely used for pipeline maintenance and repair. Therefore, authors mainly study the sealing performance of double rubber cylinder IPIT. This study first analyzed the material and geometric properties of the rubber cylinders in an IPIT to establish a numerical finite element model of cylinder mechanical behavior. The influence of the cylinder hardness, camber angle, and short-side length on the sealing performance was subsequently investigated by systematically altering the established model according to the control variable method. Next, the response surface methodology was employed to evaluate the change in model sealing performance according to the coupled action of multiple rubber cylinder parameters and identify their optimal values. [ABSTRACT FROM AUTHOR]

The integrity of caprock sealing is a crucial factor in guaranteeing the safety and long-term feasibility of CO2 saline aquifer storage. In this study, we identified three principal mechanisms that give rise to topseal failure: (1) gradual CO2 seepage through the upper cap, (2) capillary seal failure resulting from the pressure increment due to CO2 injection, and (3) localized overpressure causing cap rupture. Through the integration of numerical simulation and geomechanics, this study offers a sealing assessment for the caprock. The thorough analysis of the sealing performance of the Guantao formation reveals that after 2000 years of CO2 injection, the caprock would undergo intrusion by 35 m without any leakage risk. Moreover, investigations into CO2–water–rock interactions suggest that precipitation reactions outweigh dissolution reactions, leading to a decreased permeability and an enhanced sealing performance. The most likely fracture mode identified is shear fracture with a critical caprock fracture pressure of 36.48 MPa. In addition to these discoveries, it is significant to consider ongoing research aimed at enhancing our ability to predict and manage potential risks associated with carbon capture and storage technologies. [ABSTRACT FROM AUTHOR]

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Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The interfacial contact status of a joint determines the sealing performance of an aircraft hydraulic system, which is influenced by inevitable multiscale assembly errors and joint manufacturing deviations. To address these challenges, a novel geometric analysis model was heuristically created that incorporates assembly and manufacturing-related topographies to accurately estimate the initial relative assembly position of joint surfaces. A microscopic contact model was constructed using the reverse reconstruction approach based on measured surface characteristics. Combining the relative position, a multiscale finite element contact model was generated to investigate the impact of each scale topography on the contact state of the seal ring. The experimental data verified the simulated indentation findings, confirming the model's efficacy in estimating contact status and seal performance characteristics. It is found that the flare angle has a more obvious effect on the contact state of the sealing interface, and a 2° difference in angle under the same load can cause a 28.19% difference in contact area, which greatly affects the sealing performance. [ABSTRACT FROM AUTHOR]

The aim of this study was to solve the problems associated with the sealing and tearing failure of rubber packer cylinders during CO2 downhole injection. Using Comsol Multiphysics 6.0 software, a rubber cylinder model in a supercritical CO2 (SC–CO2) environment was established. The thermal analogy method was used to simulate the CO2 diffusion and rubber cylinder swelling process. We analyzed the deformation and stress of the rubber cylinder that was caused by temperature and pressure, with CO2 as the swelling agent. The results show that in the SC–CO2 environment, under the influence of CO2 diffusion and the consequent swelling, the rubber cylinder body is prone to large deformations, and the maximum shear stress is significantly increased, leading to the shear failure of the rubber cylinder. Reducing the initial seating pressure can alleviate the impact of deformation, whereas reducing the maximum contact pressure can cause the rubber cylinder to lose its seal. We also analyzed the influence of various factors on the maximum contact stress of the rubber cylinder, providing a theoretical basis and technical support for improving the sealing performance of rubber packer cylinders in an SC–CO2 environment. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the shape of the prismatic cell container (PCC) and the physical properties of aluminum (Al) alloys, there are limitations in fabrication with common welding methods. Magnetic pulse welding (MPW) is a promising solid-state joining process that provides fast and strong welds without heat-affected zone. Despite the growing interest in this process, there is little understanding of the sealing performance and joining mechanism of PCC structures fabricated by MPW, which is critical for prismatic cell safety. In this study, MPW was used to join the cell case (CCE) and cell cap (CCP) for the fabrication of Al3003 PCC. The sealing performance, mechanical properties and joining mechanism of MPW joints were investigated. The results showed that the overall sealing of the PCC was realized by MPW technology, and the sealing performance reached 0.8 MPa. Peeling tests showed that the strength of the MPW welds was higher than that of the parent material, and one of the main reasons for the excellent strength of the welds was the waveform interface formation. Furthermore, the appropriate collision speed and angle were the key factors for welds generation, which ranged from 315 m/s to 360 m/s and 2–10°, respectively. This study provides potential options for the fabrication of Al PCC for electric vehicles. [ABSTRACT FROM AUTHOR]

Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing (Frac) plugs during multi-stage hydraulic fracking. In practice sealing performances of such plugs are normally evaluated through pressure tests, and in numerical simulation studies, maximum contact stress, average contact stress and contact length data are used to determine sealing quality between a packer and casing. In previous studies, the impact of friction forces on sealing performance is often overlooked. This work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing performances. We first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac plug. Then we compared analytical calculation results with Finite Element Analysis simulation using a simplified tubular geometry and showed the significant influences on interfacial friction on elastomer packer stress distribution, deformation, and contact stress after setting. With the demonstration of validity of FEA method, we conducted systematic numerical simulation studies to show how the interfacial friction coefficients can affect the maximum contact stress, average contact stress, contact stress distribution, and maximum mises stress for an actual packer used in plug products. In addition, we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial stress. This study underscores the critical role that friction forces play in Frac plug performance and provides a new dimension for optimizing packer design by controlling interfacial interactions at the packer contact surfaces. [ABSTRACT FROM AUTHOR]

It is the key technology to reduce the pollution of production layer by using retrievable bridge plug to plug production string and carry out snubbing operation. This paper establishes the simulation calculation model of the small diameter bridge plug rubber tube through the rubber thermal aging experiment. The influence of rubber combination on sealing performance and safety under high temperature and high pressure was analyzed, and the rubber structure was optimized. The results show that the sealing performance of the three-rubber tube structure is about 8.7% higher than that of the double-rubber tube structure at 120 °C and 55 MPa. In order to take into account the deformation and sealing requirements of the rubber tube, the preset trapezoidal ring groove structure (groove number n, groove width l, groove depth δ) in the rubber tube is optimized. Under the condition of 35 MPa setting load, the optimized A-structure rubber tube (n = 3, l = 10.5 mm, δ = 0.5 mm) improves the sealing performance by about 21.15% and reduces the Mises stress by 4.88% compared with that before optimization. It is suitable for oil and gas wells with long-term sealing and high safety requirements. The sealing performance of the optimized B-structure rubber tube (n = 3, l = 10.5 mm, δ = 1.5 mm) can be improved by about 43.94%. Although the Mises stress is increased by 15.97%, it is still within the safe range and can be applied to the working conditions with high sealing pressure and short-term sealing. [ABSTRACT FROM AUTHOR]

The seal and weight of the Type IV hydrogen storage vessel are the key problems restricting the safety and driving range of fuel cell vehicles. The boss, as a metal medium connecting the inner liner of the Type IV hydrogen storage vessel with the external pipeline, affects the sealing performance of the Type IV hydrogen storage vessel, and there is no academic research on the weight of the boss. Therefore, according to the force characteristics of the boss, this paper divides the upper and lower areas (valve column and plate). The valve column with seal optimization and light weight is manufactured with a 3D printing additive, while the plate bearing and transferring the internal pressure load is manufactured by forging. Firstly, a two-dimensional axisymmetric simulation model of the sealing ring was established, and the effects of different compression rates on its seal performance were analyzed. Then, the size and position of the sealing groove were sampled, simulated, and optimized based on the Latin Hypercube method, and the reliability of the optimal seal structure was verified by experiments. Finally, the Solid Isotropic Material with Penalization (SIMP) topology method was used to optimize the weight of the boss with optimal sealing structure, and the reconstructed model was checked and analyzed. The results show that the weight of the optimized boss is reduced by 9.6%. [ABSTRACT FROM AUTHOR]

Traditional oil seals are insufficient for the high-speed and bi-directional rotation of new energy electric vehicles. Therefore, we developed a Python program focusing on micro-groove pump seals and examined the unexplored non-contact oil–air biphasic internal end-face seals. Real gas effects were described using the virial and Lucas equations. We introduced an oil–air ratio to determine the equivalent density and viscosity of the two-phase fluid in the seal. Furthermore, we solved the compressible steady-state Reynolds equation using the finite difference method. Analysing the seal's pumping mechanisms and the effects of operating parameters on sealing performance, we assessed 17 types of hydrodynamic grooves. The results demonstrate that inverse fir tree-like grooves perform well under typical sealing conditions. Under the conditions given in this study, the pumping rate of the optimal groove type compared to other groove types even reached 633.54%. In the oil–air biphasic state, the micro-groove pump seal exerts significant dynamic pressure on the sealing surface. Seal opening force increases with rotational velocity, oil–air ratio, and inlet pressure but decreases with temperature. The pumping rate first increases and then decreases with rotational velocity, increases with oil–air ratio and temperature, and then decreases with inlet pressure. Some special working points require consideration in sealing design. Our results provide insights into designing micro-grooved pumping seals for new energy electric vehicles. [ABSTRACT FROM AUTHOR]

Aimed at the problem of internal flow field and leakage of compressor labyrinth seal, optimization research was carried out on the cylinder side sealing teeth in the double-sided labyrinth seal structure. Three types of cylinder side sealing tooth structures, such as triangular, rectangular, and cycloidal were designed,different geometric ratios of tooth height, tooth width,and sealing tooth clearance between the cylinder side and piston side sealing teeth were selected from 1:2 to 1:6, and the double-sided sealing models with different sealing tooth structures were established.The sealing performance of the double-sided sealing models was analyzed by CFD dynamic mesh transient simulation, and was compared with that of the single-sided sealing tooth structure model. The results show that the leakage of the double-sided sealing tooth structures reduced by 25.8% to 56.0% compared with the single-sided sealing tooth structure.The sealing performance of cylinder side sealing teeth with three different shapes is in descending order: triangular, rectangular,and cycloidal. Among the five different geometric ratios of cylinder side sealing tooth models,the sealing performance is arranged from strong to weak as 1:4, 1:5, 1:2, 1:6, and 1:3. The sealing performance of the triangular cylinder side sealing tooth structure that the geometric ratio of the sealing teeth between cylinder side and piston side is 1:4 is the best,and the leakage rate is reduced by 56% compared to the single-sided sealing tooth structure. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The control rod drive mechanism (CRDM) and the pressure vessel tube seat were usually connected by a welding connection. Aiming at the problems such as the inconvenient to dismantle due to the core change and the deterioration of the seal performance of the secondary welding, the connection of the connection form of the control rod drive mechanism has been researched. A wedge-shaped labyrinth seal structure convenient for maintenance and disassembly was proposed. Firstly, the design concept of labyrinth seal was introduced, the wedge seal structure was also incorporated, and the design of the steel pressure vessel was used to compute the minimum wall thickness required for the control rod actuator mechanism under the working condition and the critical yield temperature under the coupled action of the thermal and compressive loads. Then the finite element was used to simulate the working condition of the C-ring, and the resilience characteristics of the metal C-ring and the state of the seal surface were also investigated. Finally, the wedge labyrinth seal assembly was subject to the leakage rate test and a thermal cycle test of experiments for verification. The results show that the minimum wall thickness under working condition is 10 mm, and the critical yield temperature is 72. 5 °C; the larger the size of the C-ring, the smaller the maximum linear specific pressure value is, and the higher the degree of sealing surface fit; the leakage rate of the wedge labyrinth sealing assembly is less than 1. 0 × 10-6 Pa·m³/s, and it can satisfy the sealing requirements of the working condition under multiple disassembly. [ABSTRACT FROM AUTHOR]

Taking the maximum contact pressure as the objective function for, the optimal design model of the offshore flange connector was established to analyze the impact of the flange cone's angle and the curvature radius of the lenticular gasket's contact surface on the sealing performance of the connector. An optimized three-dimensional model of the offshore flange connector was constructed using the MATLAB software's fmincon function to obtain the optimal size of the cone angle and curvature radius. The maximum contact pressure and maximum equivalent stress values of the nonoptimized and optimized offshore flange connectors under the cross combination of two design pressures and six operating temperatures were analyzed by Workbench software, and the sealing performance of the non-optimized and optimized offshore flange connectors was compared according to the sealing judgment basis. The results show that compared with the previously studied offshore flange connector, the sealing structure of optimized offshore flange exhibits maximum increase in contact pressure increase but maximum decrease in equivalent stress. Under actual operating circumstances, the optimized offshore flange connection performs better in sealing and is less prone to breakage. [ABSTRACT FROM AUTHOR]

Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A model based on a three-dimensional fractal function is developed and used in conjunction with experiments to analyze the evolutionary pattern of sealing performance during the start-up process of dynamic pressure seals, and the influence of end-face microscopic features on the evolution law is discussed. It is found that the opening state of the seal is divided into three stages: the non-opened stage, transition stage, and full-opened stage. The isotropic dimensions of the cavities have a coupling effect on the leakage, and they diminish as the speed increases. In order to enhance the sealing performance during start-up, it is suggested that the seal faces have a fractal dimension of 2.4 to 2.6, and a characteristic factor of less than 1 × 10−9 m. [ABSTRACT FROM AUTHOR]

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents an experimental and theoretical investigation into the factors influencing the sealing performance of combined slip rings. Factoring in the frictional heat from micro convex bodies and convective heat exchange between the slip ring, oil film, and air, we formulate a thermoelastic flow hybrid lubrication model for the combined slip ring seal. This model calculates the distribution of oil film thickness, pressure, temperature, velocity, and viscosity in the sealing zone, drawing on the generalized average Reynolds equation and the transmembrane average energy equation, in conjunction with the heat conduction equation of the slip ring. Utilizing the Archard wear model, we also examine the wear characteristics of the combined slip ring seal, providing insights into seal wear under these conditions. The model enables an analysis of the interplay between parameters and their impact on seal performance. The method proposed accurately predicts friction and leakage in line with experimental data, thereby providing a theoretical foundation for further numerical investigation of seal characteristics. [ABSTRACT FROM AUTHOR]

Abstract The drill tail of a rock drill meets high-frequency fretting in both the rotational and axial axes. The pure water seal is prone to damage and failure owing to its difficult working features and the low viscosity of the water medium. Orthogonal testing is used to simulate and model the Y-shaped seal ring to enhance the performance of the water seal. The maximum contact stress and maximum Von Mises stress are selected as indicators of sealing effectiveness based on an assessment of the effects of different seal section parameters on sealing performance. These insights serve to improve the building of the water seal. Maximum contact stress is demonstrated to be linked to lip thickness and chamfer length, but inversely proportional to lip length. Meanwhile, the maximum Von Mises stress is directly influenced by lip depth, including the angle of the lip and drill tail, and is inversely linked to lip thickness. Maximum contact stress and maximum Von Mises stress are lowered by 15% and 45%, respectively, in the revised Y-shaped water seal, resulting in greatly better sealing performance.

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the process of constructing deep natural gas wells in Sichuan and Chongqing, gas wells encounter various technical challenges such as high temperature, high pressure, and a corrosive environment containing H2S and CO2. The corrosion of rubber materials in these acidic environments can easily lead to seal failure in downhole tools. To better investigate the corrosion resistance of rubber materials in acidic environments, we utilized a dynamic cyclic corrosion experimental device capable of simulating the service conditions experienced by downhole tools under high-temperature, high-pressure multiphase flow. Corrosion-resistance tests were conducted on fluororubbers (FKM) 1, 2, 3, and HNBR (hydrogenated nitrile-butadiene rubber) under acidic conditions (80 °C and 160 °C), along with sealing corrosion tests on O-rings. These tests aimed to analyze the mechanical properties, hardness, and corrosion resistance before and after exposure to acid media as well as the sealing performance of O-rings. Ultimately, our goal was to identify suitable rubber materials for acidic pressure environments. Experimental results revealed that all four types of rubber exhibited decreased elongation at break after undergoing corrosion testing; however, fluororubber 3 demonstrated significant susceptibility to temperature effects while the other three types showed minimal impact from temperature variations. Fluororubber 1 and fluororubber 3 displayed substantial deformation levels whereas mechanical properties greatly deteriorated for fluororubber 2. Overall, HNBR showcased superior comprehensive performance. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the safety hazards of blowout prevention during the lifting process of rod and pipe in pumping wells with a diameter of 70 mm and above, the structure of the blowout prevention and disconnection device was optimized and designed. The blowout prevention technology for big pump oil pipes in pumping wells was formed through research, and an evaluation method for the safety of blowout prevention during the process of string operation was established by combining theoretical and numerical simulation methods. Firstly, the strength of the use of the blowout preventer during the docking process was analyzed through numerical simulation. Then, a study was conducted on the strength and sealing performance of the sealing system of the blowout prevention and detachment device during the process of lifting and lowering the sucker rod. Based on the analysis of the buckling behavior of the process string during the process of lifting and lowering the sucker rod, the blowout prevention pressure limit of the blowout prevention tool was obtained, with a value of approximately 30. 85 MPa. Finally, based on the stress characteristics of the process string during the pumping process, a safety evaluation method for the blowout prevention during the operation process of the blowout prevention process string was established, and a safety evaluation chart for the blowout prevention during the operation process was designed to achieve quantitative evaluation of the blowout prevention safety during the operation process. The research results of the article can provide a theoretical basis for the safety of snubbing operations. [ABSTRACT FROM AUTHOR]

This study investigates the low-temperature and durability characteristics of fuel cell gaskets based on their cross-sectional geometry. Samples of rectangular, half-circular, and mountain shapes produced by injection molding are introduced. Experiments are conducted at −40 °C, near the glass transition temperature of EPDM (Ethylene-propylene-diene monomer), to elucidate the differences in airtightness. The maximum pressures capable of maintaining airtightness at −40 °C are 1.5, 2.1, and 2.6 bar g initially for the rectangular, half-circular, and mountain shapes, respectively. After degradation for 28 days at 120 °C, these pressures drop by 0.4, 0.6, and 1.1 bar g. Simulations suggest that enhancing sealing performance relies on increasing contact pressure via a smaller contact area but it causes rapid degradation due to the internal stress concentration. Hence, achieving an optimal design balancing airtightness and durability under high pressure is crucial. In this study, it is concluded that the half-circular shape demonstrates the most stable structural performance in this regard. [Display omitted] • The properties of gaskets with rectangular, half-circular, and mountain cross-sections were studied. • The characteristics of the gasket cross-section at −40 °C were explored and the durability test at 120 °C were conducted. • A sample similar to a gasket for a real fuel cell was produced by injection molding. • The half-circular cross-section was the most advantageous in terms of durability. • Compression set test reflected changes in airtightness due to degradation better than compression stress relaxation test. [ABSTRACT FROM AUTHOR]

The drill tail of a rock drill meets high-frequency fretting in both the rotational and axial axes. The pure water seal is prone to damage and failure owing to its difficult working features and the low viscosity of the water medium. Orthogonal testing is used to simulate and model the Y-shaped seal ring to enhance the performance of the water seal. The maximum contact stress and maximum Von Mises stress are selected as indicators of sealing effectiveness based on an assessment of the effects of different seal section parameters on sealing performance. These insights serve to improve the building of the water seal. Maximum contact stress is demonstrated to be linked to lip thickness and chamfer length, but inversely proportional to lip length. Meanwhile, the maximum Von Mises stress is directly influenced by lip depth, including the angle of the lip and drill tail, and is inversely linked to lip thickness. Maximum contact stress and maximum Von Mises stress are lowered by 15% and 45%, respectively, in the revised Y-shaped water seal, resulting in greatly better sealing performance. [ABSTRACT FROM AUTHOR]

In this paper, a finite element method is proposed to predict the contact pressure of the metal seal in the subsea pipeline connector with regard of the penetration load on the critical sealing surface. Further, a fast GA-ANN model is proposed on the basis of GA-ANN to optimize the sealing structure of the connector, which uses only 3–6 % of the calculation time compared to the traditional GA-ANN model. The fast GA-ANN is further coupled with NSGA-II in the multiple objective optimization of the sealing structure and the results are compared with that of the response surface methodology (RSM). In terms of the number of valid candidate points and the optimal candidate point, NSGA-II coupled fast GA-ANN model performs much better than RSM. The hydrostatic pressure tests were carried out with the optimal sealing structure by the fast GA-ANN and the results meet the design requirements very well. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)