Stop Valve Research Articles

Common failures and solutions of check valve in gathering and transportation of produced crude oil

In view of the problems in pumping wells in the No. 4 Oil Production Plant of PetroChina Huabei Oilfield Company, such as frequent failures of check valves in daily production, long shut-down time during maintenance, impact on crude oil production and high safety risk during maintenance, a new type of double-control check valve has been invented. This check valve has the dual functions of ordinary lift check valve and stop valve, which avoids the unsafety in the operation process, improves the well opening time rate of pumping wells, and has the advantages of simple operation, long service life, simple structure, convenient repairing and recycling, and considerable procurement cost is saved.

Flow mapping using 3D full-scale CFD simulation and hydrodynamic experiments of an ultra-supercritical turbine’s combined valve for nuclear power plant

In a typical steam turbine generator system, electrical power output is related to the steam flow regulated by a control valve. Hence, to ensure adequate electrical load as well as the proper stability of the turbine, a linear operation of the control valve is desired. However, in reality, the control valve exhibits different flow characteristics (FCs), both linear and nonlinear, which stem from its complex shape of plug and stem lift. Therefore, precise estimation of FCs is of utmost importance for better controllability, reliability, and safety of the turbine system. In this study, experiments and CFD simulations were carried out to evaluate the hydrodynamic FCs of a combined emergency stop and control valve to be employed in an ultra-supercritical (USC) turbine system for power plant. A full-scale prototype valve was designed, fabricated, and tested for a vendor company. Experiments were performed in the so-called VELO (Valve Engineering Layout Operation) test bench, and CFD simulations were conducted using a commercial code STAR CCM+. Air was used for experiments and simulations for simple economic and safe operation. Hydrodynamic characteristics were analyzed, and the theoretical mass flow rate of the valve was estimated. Finally, the valve coefficient of the turbine system was determined from the obtained FC curves. The simulation and test data showed a scale deviation of 15–16% for the original model valve and the simplified test valve. The test valve required such scaled modification to match with the test bench and fabrication. The prospective future research and improvement were recommended. This study's findings would support improving the turbine system performance to ensure safer, reliable, and modular power conversion systems for nuclear and conventional fossil fuel-based power plants.

Correction to: Improvement of a Set of 13Cr11Ni2W2MoV Steel Mechanical Properties for Critical Components of Stop Valves of Oil and Gas Pipelines Using Intercritical Quenching

Correction to: Improvement of a Set of 13Cr11Ni2W2MoV Steel Mechanical Properties for Critical Components of Stop Valves of Oil and Gas Pipelines Using Intercritical Quenching

Effect of long term aging on Microstructure and precipitates of valve bolts in power plant

10Cr11Co3W3NiMoVNbNB is used as the materials of Intermediate Pressure Control Valve, High Pressure Control Valve, and Main Stop Valve in some thermal power plant. After 45,000 hours of operation, the mechanical properties of this those materials has have been decreased greatly. By means of scanning electron microscopy, transmission electron microscopy and thermodynamic software simulation analysis, the conclusions can be drawn: under this operation environment, the coarsening of martensite lath and the dissolution-reprecipitation of second phases such as M23C6 carbides and MX phases are the main reasons which result in the decrease both in the room mechanical properties and high temperature mechanical properties of materials.

Calculation of sealing pressures of shut-off valves

The proposed algorithm for calculating the sealing pressures of the shut-off valve allows one to take into account the structural features of its components and their elements that affect the amount of sealing pressures. These parts are divided into the mounting system and sealing system. Analytical dependencies for determining the forces acting in these systems allow us to determine the force values when tightening fasteners, during pressure buildup and release, and also when exposed to temperatures. When calculating the specific structure of the shut-off valve, it is shown that the forces in its sealing system and mounting system exceed the values determined by known methods of calculation, respectively, 1.4 and 1.2 times. The magnitude of these discrepancies for different structures of shut-off valves may differ from those indicated and depends on the number of components included in the stop valve station. In this regard, the proposed calculation method allows determining not only the forces in the shut-off valve, but also the optimal number of components and connections that will ensure safe operating conditions. It is shown that the method of calculating forces in the stop valve station used in practice is a special case in which the stiffness coefficient of the stop valve station α = 1. The proposed calculation method makes it possible to more accurately determine the forces acting in the shut-off valve, the sealing conditions and the stress-strain state of the components. The introduction of the developed calculation method is connected with the development of a regulatory document on its basis to replace the existing methods of calculating the stop valve station in shut-off valves.

Electrotechnical complex for autonomous power supply of oil leakage detection systems and stop valves drive control systems for pipelines in arctic region

The article is dedicated to the important task of detection and elimination of liquid hydrocarbon leak in oil pipelines. The technological, regulatory and geographical aspects of the use of existing oil leakage detection systems (LDSs) and pipeline stop valves drive control systems are considered. The authors have proposed a new solution for autonomous power supply of oil LDS and stop valve drive control systems for pipelines located in inaccessible areas. The proposed autonomous power supply complex is based on thermoelectric generation units. The composition and parametric sufficiency of the autonomous complex is substantiated. The authors have developed the laboratory test bench, which verified the technical characteristics of the complex. The authors have substantiated the possibility of various designs for application of such complexes in existing pipelines.

Можливості застосування електромеханічного обладнання для компенсації реактивної потужності та підвищення надійності електропостачання

У статті розглянуто систему електропостачання підприємства хімічної промисловості. При проектуванні таких систем необхідно проводити вибір найбільш доцільного варіанту використання електрообладнання. Вибір здійснюється на основі всебічного аналізу технічних і економічних показників. Розглянуто рішення щодо забезпечення безаварійної роботи енергосистеми, яка живить підприємство хімічної промисловості.Для компенсації реактивної потужності, яка споживається електроустановками промислового підприємства, можуть бути застосовані синхронні компенсатори, а також використовуються синхронні машини.

Autonomous capillary microfluidic devices with constant flow rate and temperature-controlled valving.

In this paper, we report on a capillary microfluidic device with constant flow rate and temperature-triggered stop valve function. It contains a PDMS channel that was grafted by a thermo-responsive polymer poly(N-isopropylacrylamide) (PNIPAm). The channel exhibits a constant capillary filling speed. By locally increasing the temperature in the channel from 20 °C to 37 °C using a microfabricated heater, a change of the surface wettability from hydrophilic to hydrophobic is obtained creating a hydrophobic stop valve. The valve can be reopened by lowering the temperature. The device is simple to fabricate and can be used as an actuatable capillary pump operating around room temperature. To understand the constant capillary filling speed, we performed contact angle measurements, in which we found slow wetting kinetics of PNIPAm-g-PDMS surfaces at temperatures below the lower critical solution temperature (LCST) of PNIPAm and fast wetting kinetics above the LCST. We interpret this as the result of the diffusive hydration process of PNIPAm below the LCST and the absence of hydration on the hydrophobic PNIPAm thin layer above the LCST.

A method of sequential liquid dispensing for the multiplexed genetic diagnosis of viral infections in a microfluidic device.

In this study, we introduce polydimethylsiloxane (PDMS)-based microfluidic devices capable of sequential dispensing of samples into multiple reaction microchambers in a single operation to provide a fast and easy sample-to-answer platform for multiplexed genetic diagnosis of multiple viral infectious diseases. This approach utilizes the loop-mediated isothermal amplification (LAMP) method to amplify and detect specific nucleic acid (DNA/RNA) targets. We present a microfluidic flow control theory for sequential liquid dispensing phenomena, which provides design guidelines for device optimization. The device specifications, such as the possible dispensing number and maximal allowable flow rate, can be theoretically designed by optimizing the geometric dimensions of the microchannels and a pair of passive stop valves integrated into each microchamber together with the water contact angles of the materials used to fabricate the microfluidic devices. In addition, a passive stop valve with a vertical-type phaseguide structure was designed to improve device performance. We could simultaneously diagnose coronavirus disease 2019 (COVID-19) and other infectious diseases, such as severe acute respiratory syndrome (SARS), seasonal influenza A, and pandemic influenza A (H1N1) 2009. The colorimetric reverse transcription LAMP (RT-LAMP) assay suggests that the four viral infectious diseases can be detected within 30 min using a hue-based quantitative analysis, and the naked eye using our microfluidic devices.

Laboratory modeling of hydrodynamic instability and sound generation processes in the ship NPS

This work is devoted to investigations of the self-oscillation regimes in the model of emergency stop valve chamber in the ductline of the systems of heat exchange in the ship nuclear power setup (NPS). Experiments were carried out on special aeroacoustical setup with simultaneous use of PIV methods for measuring velocity fields and measurements of sound generation characteristics. Dependency of parameters of self-oscillation regimes on the parameter of the length of the gap between the inlet and outlet ducts in the chamber was investigated. An explanation of the observed regimes was proposed.

Evolution in Microstructure and Mechanical Properties of Inconel 783 Alloy Bolts after Long Term High-Temperature Aging at 700 °C

This paper described systematically the changes in microstructure and mechanical properties of Inconel 783 alloy after a considerably long time (equivalently 55,000 h, about 76.4 months) of thermal exposure. Based on the Inconel 783 alloy bolts of an intermediate pressure main stop valve used in a 1000 MW ultra-supercritical unit, the evolution of microstructures and mechanical properties were studied after 700 °C aging temperature with different aging times (1000 h, 3000 h and 20,000 h, corresponding to about 1.4 months, 4.2 months and 27.8 months, respectively), using an optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffractometer (XRD), a universal tensile testing machine and impact testing machine. The results indicated that the bolts aged for 1000 h in two temperatures, showing the second needle β phase, of which the quantity and size obviously increased with aging time. Meanwhile, the characteristics in quantity and shape of the primary β phase changed obviously with the aging time, which transformed to strip the Ni5Al3 and Laves-Nb-rich brittle phase in the matrix after aging for 20,000 h. The size of the γ’ phase grew bigger with aging time, and orientation distributions have been observed obviously at 3000 h aging in 700 °C. Compared with the 650 °C aging temperature, the coarsening of γ’ precipitates and second needle β, the orientation distributions of γ’ were more obvious at the 700 °C aging temperature with aging time, which resulted in the rapid decline in yield strength and tensile strength and obvious increase in the brittleness for Inconel 783 alloy bolts.

Remote area power supply system for oil leakage detection systems and stop valves drives for pipelines

This paper describes problem of electrical power supply of data collection points for leakage detection and stop valve control systems, designed for emergency shutoff of fault parts of oil pipelines in areas without centralized power supply. Autonomous electrical power supply complex, based on thermoelectric generators and photovoltaic panels, was proposed as a solution. Structure and parametric sufficiency of power supply system were established. Computer model for estimation of autonomous power system effectiveness was developed and validated.

Capillary stop valve actuation by thermo-pneumatic- pressure for lab-on-chip systems

A novel method is presented for triggering a robust capillary stop valve fabricated in silicon using the thermal expansion of trapped air bubble (with a footprint of just 300 μm × 320 μm) as the actuation element. A heating element on the backside of a bubble trap chamber is utilized for thermal expansion of the air bubble. A voltage pulse of around 6 V, the capillary barrier, around 1400 Pa was easily breached. A non-dimensionalized model has been developed using equivalent circuit model to describe the complex thermal/hydraulic behavior of the system. The trapped gas bubble temperature is input as a function of time in the model. A thermal finite element-based simulation is conducted to determine the gas temperature from the experimentally measured heater temperature. The model results are validated against experiments to aid in characterizing the dynamics of the problem.

Effect of aging at 650 °C on microstructure and mechanical properties of GH783 alloy bolt

Taking the GH783 alloy bolt of intermediate pressure main stop valve used in 1000 MW ultra-supercritical unit as the research object, the optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) and mechanical performance tests were carried out to study the microstructure transformation and mechanical properties of GH783 alloy bolts at different aging stages under 650 °C aging environment. The results showed that the secondary needle β phase began to appear in the bolts aged for 1000 h, and the density of secondary β-phases in bolts aged for 3000 h significantly increased. When the aging time reached up to 20,000 h, the secondary β phase coarsened significantly. At the same time, as the aging time prolonged, the morphology and quantity of the primary β phase changed significantly. In terms of mechanical properties, the tensile strength and impact toughness of the bolts gradually decreased. This was due to the growing γ' phase, the formation of Ni5Al3 phase and the Nb-rich Laves phase in the structure during the aging process.

Optimization and Improvement of Electric Drive Valve Diagnostics Process During Pre-Commissioning Activities at NPP Units Under Construction

The article discusses the need for technical diagnostics of electric drive stop valves, and there are presented applied methods for evaluating the technical condition. In addition, an approach to the organization of commissioning works related to the configuration of electric drive valves is revealed, based on their combination with diagnostic support, which allows to improve the quality and efficiency of autonomous and complex commissioning as well as to increase the effectiveness of technical management of hydraulic tests and reduce their duration.

A Microfluidic Diagnostic Device Capable of Autonomous Sample Mixing and Dispensing for the Simultaneous Genetic Detection of Multiple Plant Viruses.

As an efficient approach to risk management in agriculture, the elimination of losses due to plant diseases and insect pests is one of the most important and urgent technological challenges for improving the crop yield. Therefore, we have developed a polydimethylsiloxane (PDMS)-based microfluidic device for the multiplex genetic diagnosis of plant diseases and pests. It offers unique features, such as rapid detection, portability, simplicity, and the low-cost genetic diagnosis of a wide variety of plant viruses. In this study, to realize such a diagnostic device, we developed a method for the autonomous dispensing of fluid into a microchamber array, which was integrated with a set of three passive stop valves with different burst pressures (referred to as phaseguides) to facilitate precise fluid handling. Additionally, we estimated the mixing efficiencies of several types of passive mixers (referred to as chaotic mixers), which were integrated into a microchannel, through experimental and computational analyses. We first demonstrated the ability of the fabricated diagnostic devices to detect DNA-based plant viruses from an infected tomato crop based on the loop-mediated isothermal amplification (LAMP) method. Moreover, we demonstrated the simultaneous detection of RNA-based plant viruses, which can infect cucurbits, by using the reverse transcription LAMP (RT-LAMP) method. The multiplex RT-LAMP assays revealed that multiple RNA viruses extracted from diseased cucumber leaves were successfully detected within 60 min, without any cross-contamination between reaction microchambers, on our diagnostic device.

Development of the Method for Assessment of Potential Zones of Destruction of Process Pipelines

The main technological equipment of hazardous production facilities are columntype devices with piping arrangement, which provide interconnection between individual pieces of equipment. In use process pipelines experience the considerable internal and external loads and impacts that is related to unstable work of the complex technical system and with features of its operation. Exceeding allowable loads can lead to depressurization of pipelines that, if the equipment is located close, can lead to the development of an accident with a “domino effect”.Pipeline systems are a source of the increased danger because of a large number of welded and flange joints, stop and control valves, hard conditions of operation and the considerable the volume of the flammable substances moved on them. In this regard there was a need for development of a method which will allow to estimate potential zones of destruction of pipelines at realization of accident with “domino effect”

Monitoring the Thermal Stress State in Steam Turbines

The principles of a program for monitoring stresses in rotors and bodies of stop and control valves of nonreheat steam turbines of up to 180 MW capacity to control the startup processes are formulated. The program based on the experimental data obtained by the VTI and ORGRES and calculated results obtained with the finite-element method is intended for microcomputers with hardware integrated into the electronics of the control system or the automatic process control system. Using the data from the regular control and measuring instruments, the program estimates the stresses in the “critical” elements of the steam turbine, compares them with the level permissible for the material, depending on the operating temperatures, service life, design and other parameters, and generates signals to adjust the startup process. The equivalent operating hours can also be calculated to assess the quality of startups and shutdown processes, accumulated damage, and relative past life. These data can be taken into account when deciding on maintenance operations. The algorithm of the stress monitoring system is implemented in the program limiting the rate of spinup and power change from the thermal stress state of the rotors of the high- and intermediate-pressure cylinders of the T-185/210 – 16.0 turbine.

Improvement of a Set of 13Cr11Ni2W2MoV Steel Mechanical Properties for Critical Components of Stop Valves of Oil and Gas Pipelines Using Intercritical Quenching

A heat treatment regime for steel 13Cr11Ni2WMoV quenched from 980°C with the aim of simultaneous achievement of the required values of impact toughness and strength is investigated. It is established that the optimum condition of the heat treatment regime after high-temperature quenching is double tempering, the first of which is above Ac1 and is intercritical tempering. It is demonstrated that an increase in the first tempering temperature improves impact strength considerably in the final condition, and a reduction in second tempering temperature improves steel strength. A new heat treatment regime is proposed with which the temperatures of two-stage tempering are 765 and 635°C. Mechanical property values are achieved satisfying component specifications and there is a reserve for impact strength that is important for large components.

Интенсификация работы систем водоснабжения и водоотведения г. Нижнеудинска

The paper proposes an approach to intensifying the operation of water supply and sanitation systems. The work was conducted using electronic modelling, calculation methods of hydraulic parameters and numerical modelling, as well as optimization of technical solutions for adjustment of operation modes, minimization of water leakage, pressure stabilization in the network, elimination of blockages and failures of regulating and stop valves. The efficacy of the proposed approach was demonstrated by the example of the city of Nizhneudinsk. As a result of the conducted research, information and computing systems and complexes were developed for simulating different modes of operation, assessing the performance, reliability and regime controllability of water supply and wastewater disposal systems, storing, analysing and accumulating information on the state of the system under analysis and its individual parameters. Such an approach served as a basis for developing a prospective scheme of development and reconstruction of the city water supply and sewage systems and provided an automated control system of its technological processes.