Valve Seat Research Articles

Design and development of a cryogenic J-T valve for a 2 K cryostat with a single cryocooler

Abstract A cryogenic Joule-Thomson (J-T) valve for a 2 K cryostat cooled with a G-M cryocooler has been developed to continuously supply superfluid helium. Saturated liquid helium flowing through the valve transitions to superfluid helium below 2 K because of the J-T effect. The heat leak, sealing performance and the J-T effect of the valve were tested experimentally and analyzed. To reduce heat leak in the 2 K range, two thermal anchors were installed in the first and second cooling stages, respectively, resulting in 89.93% reduction of useful work loss. A unique sealing structure was developed for the J-T valve and was tested at both room temperature and liquid nitrogen temperature, yielding leak rates of 3 × 10-9 Pa· m3/s and 3 × 10-4 Pa· m3/s, respectively. The corresponding valve needle and seat structure were designed based on the flow resistance equation. The J-T effect of the valve in 2 K cryostat was tested at various valve openings. The cryostat can operate at 1.64 K with no load and provide 0.143 W cooling power at 2 K.

Novel thermoplastic microvalves based on an elastomeric cyclic olefin copolymer.

Microfluidic systems combine multiple processing steps and components to perform complex assays in an autonomous fashion. To enable the integration of several bio-analytical processing steps into a single system, valving is used as a component that directs fluids and controls introduction of sample and reagents. While elastomer polydimethylsiloxane has been the material of choice for valving, it does not scale well to accommodate disposable integrated systems where inexpensive and fast production is needed. As an alternative to polydimethylsiloxane, we introduce a membrane made of thermoplastic elastomeric cyclic olefin copolymer (eCOC), that displays unique attributes for the fabrication of reliable valving. The eCOC membrane can be extruded or injection molded to allow for high scale production of inexpensive valves. Normally hydrophobic, eCOC can be activated with UV/ozone to produce a stable hydrophilic monolayer. Valves are assembled following in situ UV/ozone activation of eCOC membrane and thermoplastic valve seat and bonded by lamination at room temperature. eCOC formed strong bonding with polycarbonate (PC) and polyethylene terephthalate glycol (PETG) able to hold high fluidic pressures of 75 kPa and 350 kPa, respectively. We characterized the eCOC valves with mechanical and pneumatic actuation and found the valves could be reproducibly actuated >50 times without failure. Finally, an integrated system with eCOC valves was employed to detect minimal residual disease (MRD) from a blood sample of a pediatric acute lymphoblastic leukemia (ALL) patient. The two module integrated system evaluated MRD by affinity-selecting CD19(+) cells and enumerating leukemia cells via immunophenotyping with ALL-specific markers.

Cam Profile Design of Low-Speed Marine Diesel Engine Based on the Grey Theory

The camshaft profile is one of the important parameters of the engine, the reasonableness or otherwise of its design directly influences the engine’s power output, fuel consumption, emissions, noise and reliability. However, most existing cam profile optimization designs are based on the basic software operation, profile parameter selection and tuning lack a scientific theoretical basis. In order to address this issue, this study establishes a single valve kinematic model of the gas delivery mechanism of diesel engines by using the AVL-EXCITE Timing Drive, and performs a model-based multinomial kinematic acceleration cam profile design. Subsequently, an orthogonal design method is employed to obtain the parameter combinations that can satisfy the dynamic requirements. The research investigates the influence of cam profile design parameters (C 4, p, q, r, and s) on valve fullness, maximum jerk, cam contact stress, and valve seating force through a systematic study. Lastly, based on the grey correlation theory, a thorough analysis of the performance indices of cams with different profile parameter combinations is conducted. The optimization problem of the profile parameters with multiple performance indicators is transformed into a single-objective grey relational optimization problem, resulting in the optimal cam profile parameter combination of C4 =0.1, p=14, q=20, r=28 and s=36. The optimal method proposed in the paper is straightforward to implement and is applicable to the optimum design of cam profiles of the engine, which is of great importance for the optimal design of cam fabrication processes.

Flow analysis of a control ball valve in a common rail fuel injector

The electronic control common rail fuel injection system is one of the key technologies being used in modern diesel engines to improve the engine performance. A numerical simulation was conducted to study the characteristics of the fuel flow around the ball valve in the common rail fuel injector. The lift of the control ball valve and static pressure of the flow field around the control ball valve were measured respectively. The simulation was performed with the measurements as boundary conditions such that the flow characteristics can be correlated with the valve lift and the pressure upstream of the ball valve. Simulation results showed that during the valve opening and closing, a high pressure area appeared below the ball valve, while cavitation appeared in the area around the control ball valve. Specifically, the cavitation mainly appeared around the sealing circle, and its upstream area and the conical surface from the entrance to a certain distance downstream. The flow throttling happened at the outlet orifice under the steady-state condition when the valve was at the maximum opening position. The cavitation around the control ball valve was more serious under higher rail pressure conditions. The formation and development of the cavitation was found to be depending on the lift position of the ball valve and pressure of the flow around the ball valve during the valve opening and valve closing. Higher value of void fraction appeared in the flow when the lift of the ball valve was at a larger opening position. It was found that cavitation around the ball valve will affect the consistency and stability of the fuel flow. And cavitation erosion found at the valve seat from a simplified durability test appeared to be close to the place where cavitation appeared from simulation. Therefore, it is suggested that simulation work can be used to examine if cavitation occurs in the flow path of the control ball valve inside the injector in design phase and make necessary changes on the design to prevent the cavitation and the resulting damages to the control ball valve in the injector.

Investigating the Impact of Operating Conditions on Relief Pressure Valve Flow through CFD and Statistical Analysis

This paper presents a comprehensive computational fluid dynamics (CFD) analysis of air/water flow through a discharge valve, focusing on four different seat–valve distances and three adjustment nozzle positions. The study investigates the velocity distribution, pressure profiles, tangential stresses, and turbulent kinetic energy within the valve and analyzes its performance under various operating conditions. Notably, peak velocities of 3210 m/s were observed between the valve seat and valve, with significant variations for different nozzle positions. Extreme pressure values centered on the valve plate, reaching 4.3 MPa. Tangential stresses were highest on the chamfered plate surface and varied on the seat, turbulent kinetic energy (TKE) exhibited randomness. This study provides valuable information for enhancing the valve’s efficiency in a wide range of industrial applications.

Increasing the wear resistance of the ICE’s valves with the laser cladding method

BACKGROUND: There is plenty of factors leading to failure and expensive repair of piston engines at their operation. One of the widespread factors capable of affecting the engine operation is combustion chamber sealing failure. During the engine operation, gases combusting in a chamber bring pressure on working surfaces of a valve and a valve seat. If these surfaces do not ensure sealing, exhaust gases begin to leak in the exhaust manifold untimely, in some cases in the intake manifold as well. In addition, filling of cylinders with inlet charge worsens. In majority of cases, combustion chamber sealing failure caused by defect formation at working surfaces of the valve — valve seat coupling. In order to avoid combustion chamber sealing failures and other issues of operation of piston engines, it is necessary to minimize working surfaces wearing by means of wear-resistant coating. AIMS: Wear- and corrosion-resistant coating of valve’s working surface to increase service life. METHODS: The factors affecting the reliability of the valve — valve seat coupling were defined by means of literary sources analysis. Laser cladding at the valve’s chamfer was conducted with the laser robotized facility based on ytterbium fiber laser. Quality of the coated surface at the valve’s working chamfer was defined by means of metallographic study and liquid penetrant test. RESULTS: After laser cladding of the PR-08Kh17N8S6G powder material at the valve’s working chamfer, the uniform coated surface with microhardness of 435–485 HV (44–48 HRC) was obtained. CONCLUSIONS: The study results may be used for development and implementation of new kinds of wear-resistant surfaces that make it possible to increase the service life and to repair worn-down surfaces of components.

Studying the adequacy of the neural network level controller in the automated control system of an evaporator

The aim of the study is to substantiate the use of neural network control of beet juice level in an evaporator by evaluating the accuracy and adequacy of the model. This allows us to assess how well the model properties describe the course of the real process. The use of mathematical statistics methods is the most common way to test models for adequacy. In the automation scheme of level control, capacitive level gauges are used as a sensor. The actuators are pneumatic seat valves with a built-in throttle and an electropneumatic converter. The use of neural network controllers is found only in some specific cases of intelligent control of the evaporation process, and there are no data comparing the use of intelligent controllers with classical ones. In this paper, the Durbin-Watson d-criterion is used to assess the adequacy of the model. Statistical data on the behavior of the level control system circuits in different operating modes using intelligent and classical controllers were collected and a model of the evaporator unit operation was built. The advantage of the Durbin-Watson criterion is its simple and fast implementation, which does not require large economic and energy costs. The accuracy of the model was also evaluated. The static error of the control quality for the levels in the five enclosures of 25–65 % (in 10 % increments) is within the range of no more than 0,2 %. The proposed model of the evaporator station operation is generally characterized by high accuracy.

Study on the design of single-seat control valve with stable flow regulation and its fluid flow characteristics and thermal stress

Aiming at technical problems such as unstable flow at small openings and uneven force on the valve core, the single-seat control valve with stable flow regulation is researched and designed. The tapered surface of the outer edge of the valve core can cooperate with the valve seat when the valve core is running stably, resulting in higher flow regulation accuracy and more stable regulation. The mechanical characteristics and flow characteristics are analyzed. The fluid flow simulation analyzes the pressure, velocity, density, mass flow rate and volume flow rate of the fluid under small and large openings of the single-seat control valve. The relationship between the maximum pressure, maximum velocity, maximum density, mass flow rate and volume flow rate of the inlet and outlet with the opening are analyzed from small opening to large opening and smaller opening. The spool motion simulation analyzes the relationship between actuator driving force, unbalanced force, linear displacement, velocity and acceleration with time. The thermal stress simulation analyzes the thermal temperature, resultant heat flow, thermal stress, thermal strain and safety factor, and the material strength meets the requirements. The valve body pressure test, valve seat sealing test, full stroke and switching time test, drift and jitter test, starting deviation test, basic error and return difference test and dead zone test are carried out on the single-seat control valve. The test results all meet the requirements. The simulation results are compared and analyzed with the test results, and the simulation results are consistent with the test result.

Simulation Study on the Influence of a Laser Power Change on the Residual Stress of a Laser-Melting RuT300 Valve Seat

In order to effectively suppress the cracking induced by the excessive residual stress of a laser-melting RuT300 valve seat, the influence of a laser power change on the residual stress was studied by constructing a finite element simulation model of a new power valve seat. The absorption rate of the laser energy on the surface of the material and the change in thermophysical parameters with temperature were taken into account in the model. The results show that the melting and phase-change-hardening areas can be obtained by the laser-melting process. With the increase in laser power, the peak temperature of the molten pool increased almost linearly. The melting zone area and the phase-change-hardening zone depth increased. When the laser power was increased from 2000 to 2600 W, the peak temperature of the laser-melting RuT300 valve seat increased from 2005.09 to 2641.93 °C, the maximum depth of the melting area increased from 0.55 to 0.86 mm, the maximum width of the melting area increased from 3.42 to 4.21 mm, and the maximum depth of the phase-change-hardening area increased from 0.55 to 0.64 mm. The circumferential residual tensile stress in the melting area was much higher than in the radial and axial directions. Along the laser scanning direction, the residual stress in the melting area increased as a whole, and the residual stress in the laser-scanning finishing area greatly increased. With the increase in laser power, the circumferential residual stress at the previous scanning moment decreased, and at the closing moment of the scan, the circumferential residual stress increased with the increase in laser power.

Research on Surface Flaw Detection of Industrial Components Based on Deep Learning Algorithm

This paper primarily focuses on the research of industrial component surface defect detection algorithms using deep learning techniques. Taking the example of defect detection in the injector valve seat of automotive engine components, currently, the inspection of such small components heavily relies on manual visual inspection or traditional machine vision methods. Manual visual inspection is inefficient and cannot guarantee the speed and accuracy of detection. Traditional machine vision methods, while efficient, are sensitive to harsh environmental conditions and can be influenced by factors such as lighting, camera positioning, and background, resulting in poor robustness and limited feature extraction capabilities. To address these issues, this paper conducts research on a deep learning-based surface defect detection algorithm for injector valve seats.

Theoretical Analysis and Numerical Simulation of the Wear of the Sealing Substrate of a High-Pressure, High-Frequency Opening and Closing Hydrogen Ball Valve.

High-pressure valves are an essential infrastructure for hydrogen refueling stations, and the issue of safety and reliability of their operation affects the efficiency of the entire hydrogen delivery system. Hydrogen ball valves are subjected to high-frequency, rapid reciprocating opening and closing for a long time, and the sealing surface between the valve seat and the ball has an uneven wear distribution problem. In this paper, a theoretical derivation of the seat wear volume and wear depth during the hydrogen ball valve adhesive wear process is presented, and a simulation model based on transient dynamics theory is established to carry out a nonlinear finite element analysis of the dynamic contact and frictional wear of the sealing structure during the opening and closing process of the hydrogen ball valve. In order to effectively reduce the wear unevenness of the sealing surface of the ball valve, a new type of valve seat sealing surface with an unequal-width structure is proposed. Comparing the sealing pressure and seat sealing surface wear depth of the ball valve before and after the improvement, the improved ball valve sealing performance is reliable, while the seat sealing surface wear distribution is more uniform.

Abrasive wear resistance of Fe3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{{3}}$$\\end{document}Al and Stellite 6 coatings for the protection of valve faces

Developing a technology that increases the service life of valve seats in CNG/LNG-powered vehicles requires the appropriate selection of material and its application technology. Commercially used valve seat materials show accelerated wear under operating conditions, especially in natural gas vehicle engines. The authors developed a new material and technological concept to protect the valve seat in CNG/LNG-powered vehicles. Two materials were used in the research: Stellite 6 alloy and Fe3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{3}$$\\end{document}Al intermetal. A commonly used material for valve seats of combustion engines is Stellite 6. The Fe3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{3}$$\\end{document}Al is the new proposed material coating for the protection of the valve seats of internal combustion engines. The article compares the abrasive wear resistance of these materials. The abrasion tests were performed on a T-11 pin-on-disc tester, and the counter-sample was steel S235JR. The test conditions were similar to those prevailing during the operation of the valves in the head of the internal combustion engine, without the influence of temperature. The results indicate that the Fe3Al intermetallic compound is characterised by a lower coefficient of friction and wear intensity than Stellite 6. The results of exploitation tests confirm that the Fe3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{3}$$\\end{document}Al phase is a prospective material to be used as a protective material on the valve seat of vehicles. The authors made a mathematical model for the wear of the newly created surface layers and proposed hypotheses regarding the wear mechanisms of these layers.

Расчет удельных давлений в задвижках при давлениях газа до 105 МПа

In power calculation of the valves, maximum specific pressures at the gate valves are determined only in the closed position, not taking into account decrease at the sealing fields contact area between the slide valve (wedge) and the valve seats in opening, throughput characteristic of the slide valve and working medium flow rate and density. Results are provided of calculating specific pressures at the gate of the slide valve DN 150 PN 25 MPa LLC “Scientific and Production Company “MKT-ASDM” at the gas pressure drop of up to 105 MPa depending on the slide walk stroke and taking into account the gas flow rate and density using the valve actual throughput characteristics. Specific pressures of maximum values were achieved in the slide valve relative stroke range of 0.1…0.2. It is recommended to determine the specific pressure maximum value taking into account reduction in the sealing fields contact area when the wedge is raised, throughput characteristic of the sliding gate valve and the working media flow rate and density. This should be done after calculating the specific pressure with gate valve closed according to the well-known method used in the valves’ power calculation

Numerical Experiments on Performance Comparisons of Conical Type Direct-Acting Relief Valve—With or without Conical Angle in Valve Element and Valve Seat

This paper conducts numerical experiments on performance comparisons of CTDARV—with or without conical angle in the valve element and valve seat. The working principles of three kinds of CTDARV are introduced. The simulation models of three kinds of CTDARV are established by utilizing AMESIM. Numerical experiments on CTDARV, with or without a conical angle in the valve element and the valve seat, are conducted and the performance comparisons of three kinds of CTDARV are obtained. The results show that: (1) When all parameters of VED, VSD, VEM, SS, CAVE&CAVS, and OD have the same value, respectively, CA-VE has the highest stable pressure, CA-VE&VS has the highest stable displacement, CA-VS has the lowest stable pressure, and CA-VE has the lowest stable displacement. The stable pressure of CA-VE is significantly higher than that of CA-VS and CA-VE&VS. The stable displacement of CA-VE&VS is significantly higher than that of CA-VE and CA-VS, and the stable displacement of CA-VE and CA-VS has little difference. (2) With the increase of VED from 13 mm to 16 mm, the stable pressure of CA-VE remains constant, while that of CA-VS and CA-VE&VS both decreases. As the VSD increases from 3 mm to 6 mm, the stable pressure of CA-VE and CA-VE&VS decreases, and that of CA-VE decreases significantly. With the increase of VEM from 0.01 kg to 0.04 kg, the stable pressure of CA-VE, CA-VS, and CA-VE&VS remains unchanged. With the increase of SS from 5 N/mm to 20 N/mm, the stable pressure of CA-VE, CA-VS and CA-VE&VS increases. With the increase of CAVE&CAVS from 15 degrees to 60 degrees, the stable pressure of CA-VE, CA-VS, and CA-VE&VS decreases. With the OD increase from 0.8 mm to 1.4 mm, the stable pressure of CA-VE, CA-VS and CA-VE&VS remains unchanged. (3) With the increase of VED from 13 mm to 16 mm, the stable displacement of CA-VE will not change, while that of CA-VS and CA-VE&VS will increase. As the VSD increases from 3 mm to 6 mm, the stable displacement of CA-VE increases, while that of CA-VE&VS decreases. When VSD is 4 mm–6 mm, the stable displacement of CA-VS remains unchanged. With the increase of VEM from 0.01 kg to 0.04 kg, the stable displacement of CA-VE, CA-VS and CA-VE&VS remains unchanged. As SS increases from 5 N/mm to 20 N/mm, the stable displacement of CA-VE, CA-VS, and CA-VE&VS decreases. As CAVE&CAVS increases from 15 degrees to 60 degrees, the stable displacement of CA-VE, CA-VS, and CA-VE&VS decreases. With the OD increasing from 0.8 mm to 1.4 mm, the stable displacement of CA-VE, CA-VS, and CA-VE&VS remains unchanged. (4) With the increase of VED from 13 mm to 16 mm, the velocity of CA-VE remains unchanged, while that of CA-VS and CA-VE&VS increases. As the VSD increases from 4 mm to 6 mm, the velocity of CA-VS remains unchanged, while that of CA-VE and CA-VE&VS decreases. With the increase of VEM from 0.01 kg to 0.04 kg, the velocity oscillation of CA-VE gradually increases, and the velocity of CA-VS and CA-VE&VS has little change. As SS increases from 5 N/mm to 20 N/mm, the velocity of CA-VE increases, while that of CA-VS and CA-VE&VS decreases. When CAVE&CAVS is 15 degrees and 30 degrees, the velocity of CA-VE is lower than that of CA-VS and CA-VE&VS. With the OD increasing from 0.8 mm to 1.4 mm, the velocity oscillation of CA-VE increases gradually, and the velocity of CA-VS and CA-VE&VS changes little.

Research on the influence of check valve on noise performance of variable frequency scroll refrigeration compressor

Check valve is one of the core components of the scroll refrigeration compressor, which can directly affect its efficiency, life, and noise performance. Traditional check valve is the reed valve. This paper deeply studies the dynamic characteristics of reed valve and reveals the main reason of the valve noise under different rotation speeds. The large noise is mainly attributing to the large pressure pulsation as well as fast circulation velocity of fluid and the severe slapping of the reed plate on the valve seat, which is influenced by the high pressure ratio of the working condition and stiffness of the reed valve. In order to reduce the noise of the check valve, the circular valve is designed to replace reed valve in this paper. At each rotation speed, the circular valve shows a continuous exhaust process, which avoids the slapping of the valve plate on the valve seat. More importantly, the exhaust is smooth and the pressure pulsation as well as the flow rate of the fluid is reduced significantly leading to the low aerodynamic noise. Therefore, compared with the reed valve compressor, the sound pressure level of the circular valve compressor at 1800, 4200, and 6600 rpm is decreased by 3.0, 5.2, and 0.3 dB, respectively.

APPLICATION OF FE3AL INTERMETALLIC PHASE FILLER METAL IN VALVE SEATING FACE HARD FACING

The exhaust valve seat face is a surface that degrades slowly as a result of mechanical and thermal stresses. There is extensive research on new materials for valves and for the improvement of valve production technology. This paper discusses the method of obtaining a filler metal made of Fe3Al intermetallic phase and the method of TIG hard-facing on a valve seating face made of H9S2 steel, evaluating the effects of essential hard-facing parameters. The resulting hard-facing build up was assessed in terms of quality using industrial radiography testing (RT).

EVALUATION OF THE STRESS-STRAIN STATE OF MAGNESIUM AND BIMETALLIC BALLS LOADED WITH PRESSURE IN A DRILLING WELL

In the oil industry, soluble balls made of magnesium alloys serve as plugs for temporary sealing of various sections wells. It is noted that magnesium is a metal with a low density, and therefore the gravitational force may not be enough to tightly press the ball against the valve seat. Therefore, the development of methods aimed at weighing the balls is relevant. This is achieved, for example, by manufacturing bimetallic balls, the shell of which is made of a degradable material, for example, magnesium or its alloys, a non-degradable material, for example, steel, is placed inside the shell. The purpose of the work is to compare the stress-strain state of magnesium and bimetallic (the shell is made of magnesium, inside the shell is a steel ball) balls during operation in an oil well. The scheme of operation and testing balloons under the influence of liquid under pressure is considered. The simulation was carried out in the DEFORM 2D software module. The size of the balls is selected from the actual application condition, in addition, in the case of a bimetallic ball, the diameter of the steel ball located inside the magnesium shell is set less than the inner diameter of the seat. This guarantees the passage of the ball through the seat hole after the dissolution of the magnesium shell. Calculations of the degree and rate of deformation, the average normal stress and the stress state index of magnesium and bimetallic balls are performed. The dangerous zone of the balls from the position of cracking is revealed — the zone of contact with the saddle, where the deformation is localized. In addition, it was found that in the case of loading a bimetallic ball, all deformation is concentrated in the magnesium shell, and the steel ball does not deform at all and in this case acts as a mandrel. The stress state turns out to be more favorable at the periphery of the balls, however, the maximum of the average voltage modulo a bimetallic ball is 16 % higher than this value of a magnesium ball. The center of the magnesium ball is subject to tensile stresses, which is not observed in a bimetallic ball. According to the results of the calculation of the stress state indicator in the dangerous zone of the balls, the level of σ/T of a bimetallic ball is on average 20 % higher than this indicator of a magnesium ball. Thus, a bimetallic ball in the process of loading with a liquid under pressure has a more favorable stress-strain state compared to a magnesium ball.

Structural Analysis and Optimization of Urban Gas Pressure Regulator Based on Thermo-Hydro-Mechanical Coupling

As a core component in the gas transmission process, the internal wall surface of a gas pressure regulator is prone to failure due to long-term exposure to a high-pressure gas environment, resulting in poor reliability of the regulator. Thus, a thermo-hydro-mechanical coupling model for the FL gas pressure regulator is established in this paper, and the thermo-hydro-mechanical coupling results are verified by engineering data. The effect of valve opening on the parameters (temperature, deformation, and stress) of the gas pressure regulator is studied in detail through simulation. The results show that the stress is greater at the sleeve, valve bore, and outlet valve seat wall under the opening of 20% of the regulator. Finally, the response surface method is used to optimize the regulator to obtain a good fit and high predictive ability of the response surface equation. The optimal parameters for the gas pressure regulator are as follows: the wall thickness of the sleeve is 7.25 mm, the diameter of the valve bore is 25 mm, and the wall thickness of the outlet seat is 31.05 mm. The maximum equivalent stress with this combination of parameters is 135.62 MPa.

Study of distribution mechanism for high water-based hydraulic motor

In coal mining, food manufacturing, and underwater applications, high water-based hydraulic motors (HWBHM) offer the advantages of high specific power and media friendliness. The water motors in these applications maintain the traditional structure and only replace the working medium with a high water-based fluid. However, the conventional plate flow distribution structures are limited by severe leakage, especially at low speeds and high pressure. In the context of underground emulsion drive systems for mining, a valve flow distribution mechanism comprising the valve and pentagon-wheel is proposed. Intaking and discharging processes of the motor are controlled by the valves, which are driven by the pentagon-wheel motion. A model of the motor is established using the AMESim simulation method to validate the feasibility of the new distribution structure. The numerical investigation into the flow filed characteristics inside valves shows that the valve seat with half-cone-angle of 45° improves the service life of the distribution structure. Performance experiment of a first-generation prototype revealed that pressure can be quickly built up in the plunger chamber at different conditions. Compared with traditional flow distribution mechanism, leakage of the valve flow distribution mechanism is 0.15 ml/min, which significantly improves the volumetric efficiency of the motor. The new flow distribution mechanism works well at high pressure, low speeds, and water-based medium working conditions.

Research on the Development, Testing, and Evaluation of the Dual-Opening Anti-Blowout Oil Draining Device

During the tripping of the sucker rods and tubing from the wells with sucker rod pumps (SRP) in Tarim Oilfield, there are multiple challenges encountered, such as heavy oil, deep pumping, substantial load differences, and corrosive gas like H2S, etc., making the traditional anti-blowout oil draining device inefficient for operational needs and environmental requirements during pumping and intervention of the producing wells. In order to resolve such problems, Tarim Oilfield has developed a novel anti-blowout oil draining device with dual-opening function of rupturing + impacting by referring to the structure of high-pressure rupturing oil draining device with high opening success rate and conducting structure analysis, strength checks, and flow capacity calculations of the oil draining valves. The novel anti-blowout oil draining devices have passed a series of mechanical tests, corrosion resistance tests, and functional tests, such as indoor constant tensile stress-corrosion test, tensile strength test, collapse strength test, HIC test, electrochemical corrosion test, and tests of tool opening and closing, making up and breaking out, etc. The theoretical calculation and test show that the novel dual-opening anti-blowout oil draining device can not only meet the requirements of deep pumping, high gas-liquid ratio, substantial loading differences, and H2S corrosion resistance, but also be used in highly deviated wells, horizontal wells, and heavy oil producers. To conclude, the novel anti-blowout oil draining device will not pose any impacts on pump colliding operations. Moreover, the pump colliding operation can be used to eliminate the gelled debris attached to the pump valve and ball seat while ensuring anti-blowout oil drainage, returning the producer back to normal production.