Log in

Relevant bibliographies by topics / Stop valve / Journal articles

To see the other types of publications on this topic, follow the link: Stop valve.

Journal articles on the topic 'Stop valve'

Author: Grafiati

Published: 4 June 2025

Last updated: 23 June 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Stop valve.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Yang, Qin, Xian Zhou Wang, Ming Yue Liu, Jing Hu, and Zhi Guo Zhang. "Optimization of Valve Block Shape Using CFD." Applied Mechanics and Materials 190-191 (July 2012): 133–38. http://dx.doi.org/10.4028/www.scientific.net/amm.190-191.133.

Full text

Abstract:

Stop valves are commonly used as fluid flow control equipments in many engineering applications. A numerical study of a three-dimensional, complex geometry, stop-check valve was performed for model validation and improved understanding of valve flow features. This paper has provided a numerical investigation of the fluid flow inside a stop valve, including the modeling and the simulation of the stop valves. According to the simulation result of original valve structure, two cone valve block shape with different gradient are presented to bring some optimization to the stop-valve. CFD simulations were conducted for different structure of the valve to verify the performance of the valve after redesign the internal flow structure. The simulation results show that the pressure drop vortex strength, maximum velocity and velocity nonuniformity of valve outlet had been reduced obviously. Furthermore, the results of the three-dimensional optimization analysis of valve shape can be used in the design of low noise and high efficiency valve for industry.

APA, Harvard, Vancouver, ISO, and other styles

2

Rui, Jing, and Zhang Lidong. "A High-pressure Relief Valve Life Measuring System Based on LabVIEW." Journal of Physics: Conference Series 2785, no. 1 (2024): 012037. http://dx.doi.org/10.1088/1742-6596/2785/1/012037.

Full text

Abstract:

Abstract High-pressure relief valves have been widely used in machinery, chemical industries, shipbuilding, and other industries, and their service life is a very important performance index. This paper presents a service life measurement system of marine high-pressure relief valves. The system mainly uses a virtual instrument to carry out remote automatic start/stop control and valve position report for the start/stop of the relief valve, confirm the start/stop status, and count the start/stop times within the specified time to reflect the service life of the relief valve.

APA, Harvard, Vancouver, ISO, and other styles

3

Yao, Mingjin, Girish Shah, and Ji Fang. "Capillary Stop Valve Design with Modified PDMS." Advanced Science, Engineering and Medicine 5, no. 1 (2013): 55–62. http://dx.doi.org/10.1166/asem.2013.1219.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Koliadiuk, Andrii S., Mykola H. Shulzhenko, and Oleksandr M. Hubskyi. "Strength and Service Life of a Steam Turbine Stop and Control Valve Body." Journal of Mechanical Engineering 24, no. 4 (2021): 61–70. http://dx.doi.org/10.15407/pmach2021.04.061.

Full text

Abstract:

The stability of operation of steam turbines depends (along with other factors) on the reliable operation of their steam distribution systems, which are based on stop and control valves. This paper considers the strength of the elements of the K-325-23.5 steam turbine valves, in whose bodies, after 30 thousand hours of operation, cracks came to be observed. Previously determined were the nature of gas-dynamic processes in the flow paths of the valves and the temperature state of the valve body in the main stationary modes of operation. To do this, a combined problem of steam flow and thermal conductivity in stop and control valves was solved in a three-dimensional formulation by the finite element method. Different positions of the valve elements were considered taking into account the filter sieve. The assessment of the thermal stress state of the valve body showed that the maximum stresses in different operating modes do not exceed the yield strength. Therefore, the assessment of the creep of the valve body material is important to determine the valve body damage and service life. Modeling the creep of the stop and control valves of the turbine was performed on the basis of three-dimensional models, using the theory of hardening, with the components of unstable and steady creep strains taken into account. The creep was determined at the maximum power of the turbine for all the stationary operating modes. The maximum calculated values of creep strains are concentrated in the valve body branch pipes before the control valves and in the steam inlet chamber, where in practice fatigue defects are observed. However, even for 300 thousand hours of operation of the turbine (with a conditional maximum power) in stationary modes, creep strains do not exceed admissible values. The damage and service life of the valve bodies were assessed by two methods developed at A. Pidhornyi Institute of Mechanical Engineering Problems of the NAS of Ukraine (2011), and I. Polzunov Scientific and Design Association on Research and Design of Power Equipment. (NPO CKTI) – 1986. The results of assessing the damage and the turbine valve body wear from the effects of cyclic loading and creep of the turbine in stationary modes for 40, 200 and 300 thousand hours show that the thermal conditions of the body in the steam inlet chamber are not violated (without taking into account possible body defects after manufacture). The damage in valve body branch pipes after 300 thousand hours of operation exceeds the admissible value, with account taken of the safety margin. At the same time, the damage from creep in stationary operating modes is about 70% of the total damage. The maximum values of damage are observed in the areas of the body where there are defects during the operation of the turbine steam distribution system. The difference between the results of both methods in relation to their average value is ~20%.

APA, Harvard, Vancouver, ISO, and other styles

5

Chen, Kun, Xiang Wei Zeng, Xiao Ping Qiu, and Xiao Ge Zeng. "Passive Control Shuttle-Type Check Valve – a New Nuclear-Class Fluid Control Component." Advanced Materials Research 317-319 (August 2011): 1474–77. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.1474.

Full text

Abstract:

A novel check valve - passive control shuttle-type check valve is introduced in this paper based on the comparison of the existing swing check valves including the liquid, structural principle, flow resistance coefficient, airproof and start-stop performances. The experimental and simulation analysis validated that shuttle-type check valve has the advantages of symmetric structure along the pipeline axis, balance circle flow, low coefficient streamline, adjustable start-stop time, multi-airproof, zero leakage and less noise.

APA, Harvard, Vancouver, ISO, and other styles

6

Goloshumova, V. N., and Yu M. Brodov. "Analysis of reliability of design of stop valve of steam turbin." Safety and Reliability of Power Industry 12, no. 3 (2019): 206–12. http://dx.doi.org/10.24223/1999-5555-2019-12-3-206-212.

Full text

Abstract:

The stop valve is one of the «critical» elements of the steam turbine installation, the heating conditions of which determine the reliability of the power unit as a whole. The stop valve for cogeneration steam turbines of subcritical parameters of "UTZ" is unified for familiesT-110/120-130, T-185/210-130/15, ПT-140/165-30/15, P-100-130/15. The sequence of analysis of the valve design is presented for conditions, where only the static temperature and steam pressure at the inlet to the valve, the steam flow rate at the outlet of it, the restrictions for movement during heating are known. The results of the analysis of calculations of unsteady gas-thermodynamic and stress-strain state of the valve during the heating of the main steam line of the turbine T-110/120-130 from the cold state according to the standard instructions are shown. The calculations were carried out by the finite element method using a three-dimensional geometric model of the valve body with a slit filter. The height of the holes in the slit filter is 3.5 mm. The equations of the Nusselt criterion for the flange, the steam box, the lower half of the steam box and the fairing when using computers with limited computing resources are presented. It is shown that the peak of the maximum stresses occurs at the initial stage of the stop valve warming up on the inner (heated) surface of the stop valve body in the area of the flange and the cover. The maximum equivalent stresses are 300 MPa. The comparison of calculated temperatures and temperatures measured during the start-up at the CHP is presented; the temperature difference does not exceed 5–6%. It is proposed to analyze the stop valve reliability with a sequence given in this article in the design of new stop valves with significant differences from the existing prototypes.

APA, Harvard, Vancouver, ISO, and other styles

7

Meng, Hai Bo, Yong Liu, and Yong Li. "Experiment on Water Hammer Protection Performances of the Shuttle Check Valve in Multi-Pump Parallel Connection System." Applied Mechanics and Materials 192 (July 2012): 37–41. http://dx.doi.org/10.4028/www.scientific.net/amm.192.37.

Full text

Abstract:

A suddenly pump stop in multi-pump parallel connection system could induce water hammer which may cause serious accidents. To prevent water hammer harm, comparing experiments was carried out to study the water hammer phenomenon in the lift closing check-valve adopted system and the shuttle check valve adopted system. The result indicates that, the shuttle check valve greatly cuts the peak-value produced by stop-pump water hammer impulsion, and reduces the probability of bringing a devastating water hammer accident.

APA, Harvard, Vancouver, ISO, and other styles

8

Grice, Dan, Larry Hanke, and Jennifer Mathias. "Analysis of Stop Valve Leaks: Environmental Stress Cracking of Styrene Copolymer Valve Stems." Journal of Failure Analysis and Prevention 22, no. 2 (2022): 666–75. http://dx.doi.org/10.1007/s11668-022-01364-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Nagovicyn, Viktor Stepanovitch, Alexandr Nikolayevitch Antropov, Andrey Leonardovitch Tsipp, and Sergey Yurievitch Grishaev. "Electro-pneumatic valve of auto-stop with the function of the EPV of AS (electro-pneumatic valve of automatic stop) reservation." Herald of the Ural State University of Railway Transport, no. 2 (2017): 28–39. http://dx.doi.org/10.20291/2079-0392-2017-2-28-39.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Chang, Yaw-Jen, Yu-Te Lin, and Chuan-Chieh Liao. "Chamfer-Type Capillary Stop Valve and Its Microfluidic Application to Blood Typing Tests." SLAS TECHNOLOGY: Translating Life Sciences Innovation 24, no. 2 (2018): 188–95. http://dx.doi.org/10.1177/2472630318808196.

Full text

Abstract:

This paper presents a novel design of a capillary stop valve with a chamfered side that can be used as a flow regulator to hold an injected microfluid in the valve position in a capillary force-driven microfluidic device. Biochemical analysis can be conducted if the chamfer-type valves are placed at strategic positions according to the test protocol. Hence, the stored reagent can be dragged out of the valve for further reaction when the specimen passes through. However, countercurrent phenomena were observed in the commonly used T-type capillary stop valve (without the chamfered side). In blood typing tests, the countercurrent led to incomplete dragging and the fluid stopped flowing at the complicated mixing channel; thus, the blood typing reaction was attenuated. On the contrary, the chamfer-type valve reduced the countercurrent phenomena and ameliorated the blood typing reaction. Consequently, agglutination results can be easily discriminated from nonagglutination cases.

APA, Harvard, Vancouver, ISO, and other styles

11

Tulai, Iulia, Kevin Harris, Judah Askew, Jay Sengupta, Joao L. Cavalcante, and Quirino Orlandi. "MITRAL VALVE PROLAPSE: WHEN DOES IT STOP BEING BENIGN?" Journal of the American College of Cardiology 75, no. 11 (2020): 2967. http://dx.doi.org/10.1016/s0735-1097(20)33594-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Heorhii, Kulinchenko, Mssliennikov Andrii, Bаhutа Viktor, and Chervyakov Vladymir. "ASSESSMENT OF EFFICIENCY OF ELECTRIC DRIVE OF STOP VALVES." Eastern-European Journal of Enterprise Technologies 4, no. 8 (100) (2019): 36–44. https://doi.org/10.15587/1729-4061.2019.174203.

Full text

Abstract:

The operation features of the stop valve electric drive are analyzed. It is found that the drive of stop valves, implemented on the basis of induction motors, is characterized by low energy efficiency. For the purposeful improvement of the energy efficiency of the electric drive, a method is developed for estimating the energy efficiency of the valve module. The need to develop the method is due to the fact that energy efficiency estimates based on international standards are valid for steady-state operating conditions, provided that the time of transient processes is neglected. Unlike traditional types of actuators, the stop valve actuator is characterized by low speeds. The use of mechanical gearboxes does not significantly reduce the drive speed, so you have to carry out pulse control of the engine or switch to a gearless drive. The efficiency of alternative engine types is estimated using the proposed method, which is based on valve positioning modeling. The trajectory of movement is formed in accordance with the control pulses applied to the windings of the motor, which is part of the mechatronic module. Testing of the method is carried out on the basis of the passport data of the 120 W AIR56A4 induction motor, which is part of a serial single-turn mechatronic module. For comparison of energy indicators, a 3-phase synchronous rolling rotor motor was chosen, whose parameters of the stator winding are similar to those of the AIR56A4 motor winding. Comparison of energy efficiency estimates showed the advantage and prospects of using gearless synchronous motors in the valve drive. The developed models allow to investigate and optimize the characteristics of the electric drive based on the tested engines, as well as to formulate the requirements for the engine design and technological parameters based on the obtained energy efficiency estimates. The proposed method of energy efficiency assessment is the basis for the implementation of a set of technical tools to assess the drive energy efficiency in real industrial conditions when performing a specific technological task.

APA, Harvard, Vancouver, ISO, and other styles

13

Stevanovic, Vladimir, Sanja Milivojevic, and Milan Petrovic. "Fluid dynamic forces in the main steam pipeline of thermal power plant upon stop valves closure." Thermal Science 24, no. 3 Part B (2020): 2213–24. http://dx.doi.org/10.2298/tsci190915426s.

Full text

Abstract:

A steam turbine trip is followed by a prompt closure of stop valves in front of the turbine and consequently to a pressure rise in the main steam pipeline. This steam hammer transient leads to the generation of intensive fluid dynamic forces that act along the pipeline axis and induce additional dynamic loads on the main steam pipeline. It is a common practice to assume a simultaneous closure of all stop valves in the safety analysis of the main steam pipeline. In the present paper computer simulations and analyses of the fluid dynamic forces are performed for several scenarios that take into account the possibility of delayed closure of the stop valve in front of the turbine. The influence of the failure of the steam by-pass line opening is considered too. The results show that the delay of the stop valve closure increases the maximum intensity of fluid dynamic force in the pipeline segment in front of the stop valve and decreases the intensity of fluid dynamic forces in segments along the pipeline. The failure of the by-pass line to open leads to prolonged steam pressure and fluid dynamic forces oscillation in pipeline segments. The simulations were performed with the in-house computer code based on the method of characteristics for the solving of the hyperbolic system of PDE that represent the mass, momentum and energy balance equations of the 1-D, compressible and transient fluid-flow. The obtained results are a support to safety analyses of thermal power plants under transient conditions.

APA, Harvard, Vancouver, ISO, and other styles

14

Kucheryavyi, V. I., and S. N. Milkov. "Evaluation of pipeline reliability in the stop-valve junction zone." Journal of Machinery Manufacture and Reliability 40, no. 1 (2011): 82–85. http://dx.doi.org/10.3103/s1052618811010109.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

&NA;. "Intensive atorvastatin does not stop progression of aortic valve stenosis." Inpharma Weekly &NA;, no. 1492 (2005): 16. http://dx.doi.org/10.2165/00128413-200514920-00039.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

ABE, Tetsuya, Ryuji TAKEDA, Yoshio MURAKAMI, Ichio ITO, and Toshi KAMOSHIDA. "All metal vacuum stop valve using shape memory alloy actuator." SHINKU 30, no. 5 (1987): 414–17. http://dx.doi.org/10.3131/jvsj.30.414.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

May, G. J. "Valve-regulated lead-acid batteries for stop-and-go applications." Journal of Power Sources 133, no. 1 (2004): 110–15. http://dx.doi.org/10.1016/j.jpowsour.2003.12.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Lee, C. S., K. B. Chandran, and L. D. Chen. "Cavitation Dynamics of Medtronic Hall Mechanical Heart Valve Prosthesis: Fluid Squeezing Effect." Journal of Biomechanical Engineering 118, no. 1 (1996): 97–105. http://dx.doi.org/10.1115/1.2795951.

Full text

Abstract:

The cause of cavitation in mechanical heart valves is investigated with Medtronic Hall tilting disk valves in an in vitro flow system simulating the closing event in the mitral position. Recordings of pressure wave forms and photographs in the vicinity of the inflow surface of the valve are attempted under controlled transvalvular loading rates averaged during valve closing period. The results revealed presence of a local flow field with a very high velocity around the seat stop of mechanical heart valves that could induce pressure reduction below liquid vapor pressure and a cloud of cavitation bubbles. The analysis of the results indicates that the “fluid squeezing” between the stop and occluder as the main cause of cavitation in Medtronic Hall valves. The threshold loading rate for cavitation initiation around the stop was found to be very low (300 and 400 mmHg/s; half the predicted normal human loading rate that was estimated to be 750 mmHg/s) because even a mild impact created a high speed local flow field on the occluder surface that could induce pressure reduction below vapor pressure. The present study suggests that mechanical heart valves with stops at the edge of major orifice region are more vulnerable to cavitation, and hence, have higher potential for damage on valve components and formed elements in blood.

APA, Harvard, Vancouver, ISO, and other styles

19

Плахотникова, Е., and E. Plakhotnikova. "CLASSIFICATION OF “ELE CTRIC DRIVE – STOP VALVE” SYSTEMS FROM POSITION OF ENERGY SOURCE USED FOR “OPEN-CLOSED” CYCLE CARRYING OUT." Bulletin of Bryansk state technical university 2016, no. 1 (2016): 74–79. http://dx.doi.org/10.12737/18263.

Full text

Abstract:

The common purpose of investigation – development of theory and methods of open-closed” systems design. The investigation problems: development of criteria for the functional compatibility of an electric drive and stop valve within the limits of a system, the classification of “electric drive –stop valve” systems from the position of energy sources used, that allows increasing a technical effectiveness, competitiveness of domestic produce and defining the ways for the realization of the priority trend of the RF in the field of import substitution. The paper is a generalization of theoretical and practical investigations of the author directed to the development of a complex approach to the design of “electric drive – stop drive” systems. The paper reposts theoretical prerequisites for the introduction of a new scientific classification of “electric drive-stop valve” systems from the position of energy types used for the realization of the “open-closed” working cycle. Basic classification variants of systems, signs of transition of one system into other, system properties within the limits of the classification offered are shown.

APA, Harvard, Vancouver, ISO, and other styles

20

Tunuguntla, H. P., I. Adachi, A. Khan, et al. "Stop the Leak! Transcatheter Aortic Valve Replacement in Pediatric VAD Patient." Journal of Heart and Lung Transplantation 38, no. 4 (2019): S37. http://dx.doi.org/10.1016/j.healun.2019.01.075.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Wu, Hui, Jun-ye Li, and Zhi-xin Gao. "Flow Characteristics and Stress Analysis of a Parallel Gate Valve." Processes 7, no. 11 (2019): 803. http://dx.doi.org/10.3390/pr7110803.

Full text

Abstract:

Gate valves have been widely used in the piping system and have attracted a lot of attention from researchers. In this paper, a wedge-type double disk parallel gate valve is chosen to be analyzed. The Reynolds number varying from 200 to 500,000, and the valve opening degree varying from 20% to 100%, and the groove depth varying from 2.3 mm to 9 mm are chosen to investigate their effects on the flow and loss coefficients of the gate valve. The results show that the loss coefficient decreases and the flow coefficient increases with the increase of the Reynolds number and the valve opening degree, while with the increase of the groove depth, the loss coefficient barely changes, but the flow coefficient increases if the Reynolds number is larger than 10,000. In addition, the effects of the gaps between the disk and the limit stop on the stress distribution of the bolt are also investigated, and the results show that if the gaps are negative, high stress will act on the bolt at the contact position between the bolt and the limit stop.

APA, Harvard, Vancouver, ISO, and other styles

22

Dai, Pengyun, Hong Ji, Qianpeng Chen, Zhaoqiang Wang, and Jinbo Wang. "Investigation of the Dynamic Characteristics of the Buffer Relief Valve of a Swing Motor Under Start–Stop Impact." Processes 12, no. 12 (2024): 2689. http://dx.doi.org/10.3390/pr12122689.

Full text

Abstract:

The swivel system of a hydraulic excavator is susceptible to pressure impact during start and stop, which significantly impacts the service life of the excavator. In this investigation into how varying speeds affect the dynamic characteristics of a swing motor’s buffer relief valve (BRV), the AMESim simulation model of the whole swing motor was established, and its validity was confirmed through experimental testing. The pressure overshoot rate and start–stop impact time of the BRV of a swing motor at 1000 rpm, 1500 rpm, and 2000 rpm, under different spring stiffnesses, were analyzed. Based on the mathematical model of the BRV, the influence of the main structural parameters of the BRV on its dynamic characteristics were analyzed using an AMESim simulation model of the whole swing motor. The results show that an increase in the rotational speed of the electric motor, while maintaining a constant spring stiffness, affects the pressure overshoot rates of both the buffer relief valve of the swing motor inlet (BRVSMI) and the buffer relief valve of the swing motor outlet (BRVSMO); specifically, when the set pressure is established at 20 MPa, the pressure overshoot rate is observed to be higher, and the start–stop impact time exceeds 25 MPa. During the start phase of the swing motor, the start impact time for the BRVSMI remains relatively constant at approximately 2.5 s, with the pressure overshoot rate stabilizing at around 0.8. Conversely, in the stop phase of swing motor, both the stop impact time and the pressure overshoot rate of the BRVSMO exhibit variability in their response to the structural parameters of the BRV. Under conditions of comparatively high pressure, it is recommended to increase the diameter of the spool damping hole, the mass of the valve core, and the viscous damping coefficient, while simultaneously reducing the guide rod diameter of the buffer plunger, as these modifications can effectively enhance the start–stop impact time and mitigate the pressure overshoot rate.

APA, Harvard, Vancouver, ISO, and other styles

23

Phillips, Elizabeth A., Rui Shen, Siyu Zhao, and Jacqueline C. Linnes. "Thermally actuated wax valves for paper-fluidic diagnostics." Lab on a Chip 16, no. 21 (2016): 4230–36. http://dx.doi.org/10.1039/c6lc00945j.

Full text

Abstract:

Wax-ink valves can be printed onto paper membranes allowing the controlled stop and start of fluid flow. Each valve can perform multiple actuation steps (e.g. open–close–open) enabling increased complexity of fluidic operations on paper platforms.

APA, Harvard, Vancouver, ISO, and other styles

24

Ivancu, Laurenţiu-Ioan, and Daniela Popescu. "Design Solutions for Large Size Ball Valves." Bulletin of the Polytechnic Institute of Iași. Machine constructions Section 68, no. 2 (2022): 51–59. http://dx.doi.org/10.2478/bipcm-2022-0014.

Full text

Abstract:

Abstract Development of sustainable cities requires safe and efficient pipeline networks for the transportation of fluids. Ball valves are usually used to start/stop the flow of liquids or gases in pipelines, because they generate low hydraulic losses when the valve is in fully open position and no leakage in fully closed position. They are highly recommended, when quick operation is needed in emergency situations. European Union and United States of America have implemented stringent laws to regulate the standards of small and medium size pipeline components. Design parameters may require large size valves that are not in the focus of the present standards and in this case, individual solutions are needed. In this work, a methodology to design ball valves that are not in the standardized series is step by step presented. The case study of a Trunnion ball valve with a 900 mm bore diameter is discussed. The standard API 6D/ ISO 14313 recommends design methods for valves with face-to-face dimension between flanges for diameters up to DN900, therefore the proposed methodology is original.

APA, Harvard, Vancouver, ISO, and other styles

25

Koroliov, A. V., P. Y. Pavlyshyn, and I. V. Bandurko. "Experimental Research of Valve Tightness at Different Closure Forces." Nuclear and Radiation Safety, no. 4(80) (December 3, 2018): 14–17. http://dx.doi.org/10.32918/nrs.2018.4(80).03.

Full text

Abstract:

Power valves are installed on almost all the pipelines of nuclear power plants performing the functions of regulation and shutting off the flow, so its failure often leads to emergencies. A particularly large number of failures is observed in motor-operated valves. Incorrect setting of the limiting clutch leads either to incomplete closure of the valve or to rod failure. Therefore, the valves are equipment of a nuclear power plant, which often falls into repair shops. Failures leading to an increase of valve leakage are especially dangerous for nuclear power plants. In this case, leakage of high-pressure valves leads to erosion of the sealing surfaces, which only increases the leakage. Thus, it is very important to determine the optimum rotational value when the valve is closed. The lack of conditions for closure force in the standards for valve leakage complicates the issue. A bench that allows working in the air with a pressure up to 3.5 MPa was developed on valve rod to study dependence of valve leakage on the rotational moment. Four independent parameters were measured: air pressure in front of the valve under study, closure force of the valve, volume of air loss through the valve and leakage time. A standard stop valve with a nominal diameter of 15 mm and a nominal pressure of 64 atm was used for the study. The determined dependence of the leakage on torque value allows recommending a gentler mode of valve closure without significantly reducing its tightness. As a result of experimental data processing, a criterial equation is obtained linking a leakage rate, pressure drop on the valve and a rotational moment value. The received criterial equation will allow defining the compromise between valve closure force and permissible leak level according to regulatory requirements. The analysis of the “leakage/rotational moment” diagram showed the possibility to reveal the damaged valves. This possibility may be used during the incoming inspection of the valves supplied to NPP, which should significantly improve the reliability of their operation.

APA, Harvard, Vancouver, ISO, and other styles

26

OOISHI, Tsutomu, Fumiio OOTOMO, Yasunori IWAI, Yoshiki NIIZEKI, and Tomoo OOFUJI. "E101 Development of High Performance Steam Stop/Control Valve for Steam Turbine." Proceedings of the National Symposium on Power and Energy Systems 2010.15 (2010): 159–62. http://dx.doi.org/10.1299/jsmepes.2010.15.159.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Dong, Xu, Jin-song, Jin Ye, and Hu Xiao-feng. "Kinetic uncertainty analysis of the reheat-stop-valve mechanism with multiple factors." Mechanism and Machine Theory 45, no. 11 (2010): 1745–65. http://dx.doi.org/10.1016/j.mechmachtheory.2010.06.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Wang, Ji, and Jian Hua Zheng. "Stress Analysis for Electric Stop Valve of Nuclear Power Plant Considering Action of Preload and Stem Force." Applied Mechanics and Materials 313-314 (March 2013): 1210–13. http://dx.doi.org/10.4028/www.scientific.net/amm.313-314.1210.

Full text

Abstract:

The finite element model of electric stop valve with flange bolts preload and valve stem force was established to improve the valve stress calculation method which was based only on action of fluid pressure, thermal stresses and pipe reaction forces. The principle and application of pretension load elements were expounded. By ANSYS, the stresses of this valve with preload and valve stem force were calculated, and the Mises equivalent stresses contour and some values of key position of whole valve were obtained. The results indicate the influence of the stresses on the valve caused by preload of bolt mounted on the flange and valve stem force can not be ignored.

APA, Harvard, Vancouver, ISO, and other styles

29

CUI, Baoling. "Influence of Valve Core Structure on Flow Resistance Characteristics and Internal Flow Field of Throttling Stop Valves." Journal of Mechanical Engineering 51, no. 12 (2015): 178. http://dx.doi.org/10.3901/jme.2015.12.178.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Muftakhov, V. Z., I. R. Chinyayev, A. V. Fominykh, and A. V. Chernyshev. "Computational, theoretical and experimental study of the working medium flow regimes in the gate valve internal bypasses." Proceedings of Higher Educational Institutions. Маchine Building, no. 8 (761) (August 2023): 109–16. http://dx.doi.org/10.18698/0536-1044-2023-8-109-116.

Full text

Abstract:

Demand is growing in technological lines of the oil and gas industry for stop-control valves that provide the required throughput characteristic at the pressure drop of 25 MPa or more. Compared to valves, the gate valves have the lower resistance coefficient in the open position. Slide stop-control devices are widely used as the stop-control valves. The most important problems that arise in designing such devices include determination of the hydraulic and cavitation characteristics and of the specific pressure at the gate. Internal bypass introduction in the control valves makes it possible to increase regulation accuracy at the high pressure drops, and using it in the gate valves to reduce forces in displacement of the stop-control elements and specific pressure at the gate when opening/closing, as well as to determine the point of the cavitation bubbles collapse in the flow. A method for calculating hydraulic characteristics of the bypass and a method for determining its throughput characteristics on the basis of computational and theoretical research using the modern engineering analysis system are proposed.

APA, Harvard, Vancouver, ISO, and other styles

31

Boualiten, K., T. Adioui, I. Mouslim, et al. "Digestive Bleeding Revealing Aortic Valve Stenosis: Heyde’s Syndrome." Scholars Journal of Medical Case Reports 12, no. 01 (2024): 57–61. http://dx.doi.org/10.36347/sjmcr.2024.v12i01.015.

Full text

Abstract:

Heyde’s syndrome is an under reported systemic disease of gastrointestinal and cardiac manifestation in older adults. It is characterized by a triad of aortic stenosis, angiodysplasia with bleeding and acquired von Willebrand syndrome. Heyde’s syndrome is a treatable condition in most cases, especially in the current era of evolution in interventional cardiology and gastroenterology. Newer endoscopic technologies may prove beneficial. Aortic valve replacement is claimed to minimize or even stop the bleeding in such patients. The aim of our review article is to summarize the basic pathophysiology, diagnostics and management of Heyde’s syndrome.

APA, Harvard, Vancouver, ISO, and other styles

32

Li, Lanhui, Eiko Y. Westerbeek, Jeroen C. Vollenbroek, et al. "Autonomous capillary microfluidic devices with constant flow rate and temperature-controlled valving." Soft Matter 17, no. 33 (2021): 7781–91. http://dx.doi.org/10.1039/d1sm00625h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Zhang, Xiaowen, Yuhang Jiang, Xijie Song, et al. "Investigation on the Influence of Flap Valve Area on Transition Process of Large Axial Flow Pump System." Journal of Marine Science and Engineering 11, no. 2 (2023): 326. http://dx.doi.org/10.3390/jmse11020326.

Full text

Abstract:

The large axial flow pump systems used in coastal pump stations are often required to add flap valves to the gates to improve the quality of the transition process. However, due to the unclear mechanism of the additional flap valve on the transition process of the large axial flow pump system, there are many difficulties in the design and application of this feature. In this paper, six kinds of flap valves with different areas are designed. On the basis of the secondary development of the Flomaster software, the transient simulation method is used to study the impact of flap valves with different areas on the large axial flow pump system synchronous start-up process, the asynchronous start-up process, the synchronous stop process and the asynchronous stop process. The research results show that when the AOF is less than 38% Ag during the asynchronous startup, increasing the AOF can significantly improve the shunt ability of the flap valve during startup. However, in the process of asynchronous starting, the working capacity of the flap valve is less affected by the AOF. During the asynchronous shutdown process, the additional flap valve can effectively delay the attenuation of the LAPS flow and reduce the instantaneous head and power. However, when the AOF reaches 38% Ag, further increasing the AOF has no obvious gain in reducing the maximum instantaneous head and power of the LAPS. When the AOF increases from 38% Ag to 49% Ag, the maximum instantaneous head and the power of the LAPS only decrease by 2.7% and 1.4%, respectively.

APA, Harvard, Vancouver, ISO, and other styles

34

Chen, Jian Ming, Lei Sun, and Yuan Jun Cheng. "Research for Application of Save Energy Piston Valve for Water Pump Balance Control." Advanced Materials Research 614-615 (December 2012): 511–14. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.511.

Full text

Abstract:

This paper introduces new type of save energy piston valve for water pump balance control, which is save energy efficiency expert. This piston valve is designed by pneumatic theory, and drive power is delivered by air compressor or pressure air source in waterworks. Pressure air is lead into cavity of piston valve by transfer action of “two positions and five channels ” electromagnetic valve, then piston drive valve to open or close water pump. This piston valve has followed functions such as balance control action, avoiding refluence, zero flow open and close, accidental power stop for water hammer and son on. Application of this piston valve had proved saving energy to 3%.

APA, Harvard, Vancouver, ISO, and other styles

35

Hatton, Gabrielle E., Akiko Tanaka, and Anthony L. Estrera. "Ascending aortic aneurysm repair 44 years after Starr–Edwards caged-ball aortic valve replacement." European Journal of Cardio-Thoracic Surgery 54, no. 5 (2018): 962–63. http://dx.doi.org/10.1093/ejcts/ezy161.

Full text

Abstract:

Abstract We report a case of ascending aortic aneurysm repair and redo aortic valve replacement with a bioprosthesis 44 years after aortic valve replacement with a Starr–Edwards metal caged-ball prosthesis. The patient presented with a moderately stenotic caged-ball valve and a 50-mm ascending aortic aneurysm on a routine follow-up transthoracic echocardiography. We replaced the valve with a bioprosthesis at the time of aortic repair as the patient wished to stop anticoagulation therapy. Intraoperatively, we found that the cloth covering of the cage was nearly completely destroyed.

APA, Harvard, Vancouver, ISO, and other styles

36

Paswan, Ramashankar, Jayanta Das, N. Kumar, Ajit Kumar, Santosh Kumar Mishra, and Kumar Sujit. "Performance Analysis of Directional Control Valve: An Overview." Applied Mechanics and Materials 592-594 (July 2014): 1983–87. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1983.

Full text

Abstract:

Directional control valves start, stop or change the direction of flow in compressed air applications. To understand the different applications of compressed air and how valves are used, one must first have knowledge of the kinds and types of valves used by industries. This paper studies local valve control of the electro-hydraulic system. The slow response of hydraulic control valve usually becomes the hold-up of whole system performance. Although fast valves (e.g. high-bandwidth servo-valves) are available, they are far more expensive than slow valves (e.g. proportional directional control valves). To improve the performance of proportional directional control valves, three different types of controllers are synthesized. Firstly, based on the pole zero cancellation technique, an open loop compensator is designed which requires the accurate valve dynamic model information; Secondly, a full state feedback adaptive robust controller (ARC) is synthesized, which effectively takes into account the effect of parametric uncertainties and uncertain nonlinearities such as friction force and flow force. Finally, an output feedback ARC controller is synthesized to address the problem of un measurable states. Keywords: valve, hydraulic device, Simulink.

APA, Harvard, Vancouver, ISO, and other styles

37

Okoh, Alexis K., Amy Suhotliv, Fady Ibrahim, et al. "EXPEDITED MITRAL VALVE REPAIR USING ONE-STOP TEE DURING THE COVID-19 PANDEMIC." Journal of the American College of Cardiology 77, no. 18 (2021): 3195. http://dx.doi.org/10.1016/s0735-1097(21)04550-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

TAKAHASHI, Shiro, Akinori TAMURA, Nobuo SHIMONO, and Shigekazu HORI. "1020 Noise Reduction Methods of Hole-tone Generating in Main Steam Stop Valve." Proceedings of the Fluids engineering conference 2010 (2010): 299–300. http://dx.doi.org/10.1299/jsmefed.2010.299.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Sawai, Ken, Takao Ohmae, Hironori Suwaki, Masaaki Shiomi, and Shigeharu Osumi. "Idling-stop vehicle road tests of advanced valve-regulated lead-acid (VRLA) battery." Journal of Power Sources 174, no. 1 (2007): 54–60. http://dx.doi.org/10.1016/j.jpowsour.2007.04.033.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Jalali, A., and Amin Amiri Delouei. "Failure analysis in a steam turbine stop valve of a thermal power plant." Engineering Failure Analysis 105 (November 2019): 1131–40. http://dx.doi.org/10.1016/j.engfailanal.2019.07.057.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Herbandono, Khamda, Arifin Arifin, Harry Purnama, and Agus Krisnowo. "Techno Economic Review on Casting Design Steam Turbine Emergency Stop Valve (ESV) Housing." International Journal of Advanced Engineering Research and Science 5, no. 4 (2018): 165–69. http://dx.doi.org/10.22161/ijaers.5.4.24.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Xiao, Wenwen, Pengli Ge, Junhua Li, Jianshun Yang, Chao Wang, and Sizhe Gao. "Study on Optimization of Anticorrosion Technology for Valve Pit Facilities in Tahe Oilfield." Highlights in Science, Engineering and Technology 13 (August 21, 2022): 163–67. http://dx.doi.org/10.54097/hset.v13i.1346.

Full text

Abstract:

Due to the abundant underground water source, the structure of the valve pool, the non installation of water stop flange in the crossing pipeline and other problems, the leakage disease rate of the valve pool in Tahe oilfield reaches more than 80%. If it is not treated in time, the valves, pipe fittings and other facilities will be rusted, which will affect the normal operation and daily maintenance of the valves and cause serious potential safety hazards. According to the characteristics of the valve pool in Tahe oilfield, XinJiang, the performance and construction technology of different kinds of anti-corrosion materials are studied, and the best anti-corrosion materials are optimized. Through comparative research, it is found that the multi-layer petrolatum coating technology has excellent anti-corrosion performance and simple construction technology, which can completely solve the corrosion problem of the pipe fittings inside the valve pool.

APA, Harvard, Vancouver, ISO, and other styles

43

Zheng-Cun, Zhou, Cui Chun-Bai, and Zhu Xiao-Bin. "The Design of a Mechanical Temperature-driven Shut-off Valve." Journal of Physics: Conference Series 2430, no. 1 (2023): 012015. http://dx.doi.org/10.1088/1742-6596/2430/1/012015.

Full text

Abstract:

Abstract The structural design of a mechanical temperature-driven shut-off valve used in the water and steam sampling device of a power plant is designed using a Iventor drawing software. A NiTi shape memory alloy with high temperature-sensitivity is used as the driven spring to control the opening and closing of the valve. In addition to the design of the structures and common parts of the shut-off valve, the mechanical calculation and parameter-design of the driven spring are also carried out. The valve is unimpeded and can take water-steam samples under the normal state. When the temperature exceeds a 49 oC, the valve will be shut off due to the driven spring extends and the water intake will stop. When it is necessary to take water-steam samples again, it can be reset manually.

APA, Harvard, Vancouver, ISO, and other styles

44

XU, Dong. "Mechanical Jamming Analysis of the Reheat-stop-valve Mechanism in the Supercritical Steam Turbine." Journal of Mechanical Engineering 46, no. 08 (2010): 121. http://dx.doi.org/10.3901/jme.2010.08.121.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Shi, Bing, and Ye Jin. "Analysis and evaluation for assembly behaviour of reheat stop valve based on virtual prototyping." Engineering Computations 25, no. 7 (2008): 637–56. http://dx.doi.org/10.1108/02644400810899942.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Cadnum, Jennifer L., Scott H. Livingston, Scott A. Gestrich, Annette L. Jencson, Brigid M. Wilson, and Curtis J. Donskey. "Use of a stop valve to enhance disinfectant exposure may improve sink drain disinfection." Infection Control & Hospital Epidemiology 40, no. 2 (2018): 254–56. http://dx.doi.org/10.1017/ice.2018.318.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Long, Xuwei, Chong Shen, Ni He, Guoliang Zhang, and Qin Meng. "Enhanced rhamnolipids production via efficient foam-control using stop valve as a foam breaker." Bioresource Technology 224 (January 2017): 536–43. http://dx.doi.org/10.1016/j.biortech.2016.10.072.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Plekhanov, F. I., and E. F. Vychuzhanina. "Design of Manual Two-Speed Drive of Pipeline Stop Valve with Automatic Speed Switching." Chemical and Petroleum Engineering 55, no. 7-8 (2019): 642–48. http://dx.doi.org/10.1007/s10556-019-00673-y.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Zuniga, M. Geraldine, Viktor Schell, Jakob Cramer, Thomas Lenarz, and Thomas S. Rau. "Reliability of start and stop control of hydraulic actuation for the insertion of electrode arrays." Current Directions in Biomedical Engineering 7, no. 2 (2021): 109–12. http://dx.doi.org/10.1515/cdbme-2021-2028.

Full text

Abstract:

Abstract Atraumatic insertions of electrode arrays (EA) into the cochlea aim to preserve natural structures and residual hearing. However, there is a limit as to how smooth and slow a surgeon can insert an EA. As a potential solution, we recently presented a tool (cochlea hydro drive, CHD) that makes use of an infusion pump to prompt and control the desired, continuous and very slow (< 1 mm/s) forward movement for such insertions. The present work further describes the onset, delay and cessation of the hydraulic actuation in response to different start and stop mechanisms, to better understand the safety of its application for cochlear implant surgery. Methods: Our previously designed tool was used to perform insertions of an EA into an artificial scala tympani model. The prototype is designed to hold an EA, which is then actuated by a standard infusion pump programmed to operate at 0.4 mm/ and 0.1 mm/s. A tubing system between the CHD and the pump includes a three-way valve. Ten insertions were operated using the functions of the pump and ten using the valve. Results: From the programmed start to the actual movement, we observed a larger average delay using the pump’s start function (5 s at 0.4 mm/s; 17 s at 0.1 mm/s) vs. opening the valve (< 0.7 s for both velocities). Moreover, the average cessation of movement with the valve closure was almost immediate (0.7 s for both velocities; this corresponds to < 0.1 mm with the slower tested velocity), as opposed to 60- 80 s delay when using the pump’s stop function. Conclusion: The use of a 3-way valve facilitates motion cessation to the high accuracy level required for cochlear implant surgery. These promising findings support future clinical translation of our tool.

APA, Harvard, Vancouver, ISO, and other styles

50

Han, Jiazhen, Yudong Xie, Yong Wang, and Qixian Wang. "Dynamic Simulation of a Warship Control Valve Based on a Mechanical-Electric-Fluid Cosimulation Model." Science and Technology of Nuclear Installations 2021 (April 19, 2021): 1–14. http://dx.doi.org/10.1155/2021/6683871.

Full text

Abstract:

Control valves have an important function in the warship power system. In engineering practice, the fluid oscillation inside the control valve causes the additional load to the valve actuator. When the additional load is added to the original load of the valve, it is possible that the required driving force (or driving moment) of the valve is greater than the maximum force (or moment) output by the actuator, which may cause the abnormal stop of the actuator. Conventionally, the interaction effect of the valve mechanical and electric components on the valve chamber’s flow field cannot be considered in computational fluid dynamics (CFD) simulations, so the oscillating fluid loads cannot be accurately obtained. In order to solve this problem, the mechanical-electric-fluid integrated valve model, using the FLUENT and AMESim cosimulation method, was developed to embody the interaction effect between the components of each part of the control valve and exhibit the fluid oscillation during the operating process of the control valve. Compared with the pure software simulations, the unsteady flow characteristics and dynamic response of the actuator were synchronously obtained in this study, which accurately captured the sudden fluid loads required for further compensation. At the same time, the differences in performance of different valve plugs were compared. The stability time of the valve plug and oscillation amplitude of the unstable fluid loads were distinct for control valves with different flow characteristics. The results can aid in understanding the instability mechanism of the fluid load in the control valve better, which provides the calculation basis for compensating the additional load on the valve plug and improve the reliability of the control valve.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!