Plug Valves Research Articles

Analysis of fluid-structure interaction in diaphragm plug valves for filling electrolyte in lithium-ion battery cells

In this paper, the stress and the local liquid residue of the diaphragm plug valve were simulated. Simulation of the diaphragm plug valve opening process was performed by using a bidirectional fluid-structure interaction based on dynamic mesh technique. The pressure and velocity distribution of the internal flow were obtained with boundary conditions for the fluid–structure interaction during the opening process. The finite element method was used to compare the equivalent stress with FSI method. The results indicate that mechanical tensile stress plays a prominent role in determining the equivalent stress of the diaphragm, with the highest stress concentration occurring in the root region. The electrolyte flow in the valve tends to be stable when reaching an opening degree of 56.6 %. Crystallization accumulation will occur due to the existence of vortices in the flow field around the diaphragm which affects the fluidity of the fluid, this area needs to be focused on.

Comparative analysis of operation features of ball and plug valves in metallurgical slurry systems

Comparative analysis of operation features of ball and plug valves in metallurgical slurry systems

Plug Valve Surface Defects Identification through Nondestructive Testing and Fuzzy Deep-Learning Algorithm for Metal Porosity and Surface Evaluation

This paper addresses the detection and identification of flaws in Plug valves. The Plug valve thermal image is acquired using a Fluke thermal camera [TiS20]. Thermal images of the Plug valve are used for the identification of flaws such as Crack, Porosity, Corrosion, and Internal defects. The thermal images detect the surface flaws and never subsurface flaws in Plug valves. The subsurface flaws detection is a challenging problem in valve inspection. In this paper, the thermal images obtained after the dye penetrates the surface valve detect the surface flaws more efficiently after applying the Fuzzy Deep Learning Algorithms. DyePenetrating Test (DPT) combined with Infrared Thermography is proposed to identify heat flux changes and flaws in the faulty metal surface of Plug valves. In DPT, thinned paint is employed on the metal surface that displays metal porosity and even fine cracks. After DPT, thermal images of the Plug valve are processed through the Fuzzy Deep Learning Algorithm to evaluate flaws. The Fuzzy Algorithm is utilized prior to Deep Learning to simplify and speed up the classification task. The flaws are identified using Slicing operation and the following parametric quantities such as Accuracy, Mathew’s Correlation Coefficient (MCC), Local Self-Similarity Descriptor (LSS), Precision/Recall, F-measure, and Jaccard Index. The parametric quantities depict corresponding variations with regard to surface coarseness and metal flaws. The DPT and Fuzzy Deep Learning Algorithm identify metal defects with 80.67% accuracy.

Fundamental characterization of backfire in a hydrogen fuelled spark ignition engine using CFD and experiments

Backfire, an abnormal combustion phenomenon, in a hydrogen fuelled spark ignition (SI) engine was analyzed using computational fluid dynamics (CFD) and experimental tests. One of the main causes of backfire origin is the presence of any high temperature heat source including hot spot in the combustion chamber of the engine during intake process. A CFD based parametric study was carried out by varying the temperature of hot spot and its location in the combustion chamber of the engine in order to analyze their effects on backfire origin and its propagation in the intake manifold of the engine. The temperature of hot spot was varied from 800 K to till the temperature of backfire occurrence. The minimum temperature of hot spot at which backfire occurred was observed as 950 K and beyond. The probability of backfire occurrence increases with increase in hot spot temperature. The CFD simulations were also carried out by varying the location of hot spot (spark plug tip and exhaust valve) and the results indicate that the location of hot spot does not influence the characteristics of backfire but it affects the timing of its origin. The average backfire velocity is 230 m/s based on the average turbulent flame velocity during backfire propagation in the intake manifold and the value agreed reasonably well with the experimental observations of backfire propagation on the engine with the transparent intake manifold. Backfire propagation is under the category of deflagration based on its velocity (subsonic), and the maximum pressure gradient (<0.3 bar). The backfire phenomenon is characterized into three stages namely ignition delay for backfire, backfire propagation and its termination. The study results provide a better in-depth understanding of backfire origin and its propagation and would be helpful for developing a robust control strategy. Based on this study, it is recommended that the spark plug and exhaust valves of hydrogen fuelled SI engine should be customized in such a way that the temperature of spark plug tip and exhaust valves should not exceed 900 K during suction process in order to eliminate backfire occurrence.

On-chip integrated multi-thermo-actuated microvalves of poly(N-isopropylacrylamide) for microflow injection analysis

An array of thermo-actuated poly(N-isopropylacrylamide) (PNIPAAm) multivalves was designed and fabricated to perform volume-based sample injection for microflow injection analysis on a glass microfluidic chip. The PNIPAAm monolithic plug valves were prepared inside the vinylized glass channels by photopolymerization in water–ethanol (1:1) medium using 2-hydroxy-2-methyl propiophenone (Darocure-1173) as the initiator and a photo-mask for micropattern transferring. Experimental conditions for the photopolymerization were studied, and the thermo-responsive behavior of the synthesized monolithic plug valves was investigated. To perform active heating and cooling of the on-chip integrated thermo-actuated valves, micro-Peltier devices were used and operation times of 3-s for opening and 7-s for closing were obtained. In the close status, a 2-mm long monolithic plug valve could endure a pressure of no higher than 0.45 MPa. The volume-based sample and reagent injector was composed of two groups of valves (total valve number of 5) and two loops. When the two groups of valves were alternatively opened and closed via thermo-actuation, the sampling loops were able to be switched between loading and injection position without any mechanical moving parts. Cooperating with syringe pumps, the microfluidic chip with the integrated sample injector has been demonstrated for microflow injection chemiluminescence detection of hydrogen peroxide. For a sampling volume of 6 nL, linear response was observed over the H 2O 2 concentration range of 0–2 mmol L −1, and a precision of 0.6% (RSD, n = 11) was achieved for a standard H 2O 2 solution 2 mmol L −1.

Performance of expellers in evacuating gas pipelines—Part I: Measurements, models and field verification

This is a two-part paper. Part (I) presents results of measurements conducted on two different types of expellers of various sizes mounted on matching or mismatching size stacks, with equivalent flow resistance imposed by the gas pipeline section. Expeller performance in terms of its induction ratio has been found to be correlated to the system equivalent flow resistance coefficient in the form of a power-law. It was also found that the induction ratio deteriorates significantly as flow resistance is increased, and that manufacturer's specifications are typically given for full-size free-access inlet (i.e. with no flow resistance). In the field this is never the case, and hence the methodology adopted here in quantifying the performance characteristics is useful in practical applications. A model based on these characteristics has been developed for any asymmetric expelling system. Model results indicate that there is a stonewall limiting characteristic of the system beyond which, a larger size expeller does not induce higher suction flows. Two practical aspects are highlighted: (1) requirements for equal suction flows on both sides of the work-site and (2) time to complete one full sweep of pipeline gas with ambient fresh air. Effects of plug valves installed on blowdown stacks and effects of driving the expellers with natural gas are discussed in a companion paper (Part II).

Friction losses in valves and fittings for power-law fluids

Data on pressure drop were obtained in stainless steel, sanitary fittings and valves during laminar and turbulent flow of aqueous solutions of sucrose and xanthan gum, which were selected as model fluids. The rheological properties of these solutions were determined and the power-law model provided the best fit for experimental data. Friction losses were measured in fully and partially open butterfly and plug valves, bends and unions. Values of loss coefficients (kf) were calculated and correlated as a function of the generalized Reynolds number by the two-k method. The model adjustment was satisfactory and was better in the laminar flow range (0.976 < r2 < 0.999) than in the turbulent flow range (0.774 < r2 < 0.989). In order to test the adequacy of the results for predicting loss coefficients during flow of real fluids, experiments were conducted with coffee extract. Comparison between experimental and predicted loss coefficients showed very good agreement.

CAVITATION IN VORTICAL FLOWS

▪ Abstract Cavitation in vortical structures is a common, albeit complex, problem in engineering applications. Cavitating vortical structures can be found on the blade surfaces, in the clearance passages, and at the hubs of various types of turbomachinery. Cavitating microvortices at the trailing edge of attached sheet cavitation can be highly erosive. Cavitating hub vortices in the draft tubes of hydroturbines can cause major surges and power swings. There is also mounting evidence that vortex cavitation is a dominant factor in the inception process in a broad range of turbulent flows. Most research has focused on the inception process, with limited attention paid to developed vortex cavitation. Wave-like disturbances on the surfaces of vapor cores are an important feature. Vortex core instabilities in microvortices are found to be important factors in the erosion mechanisms associated with sheet/cloud cavitation. Under certain circumstances, intense sound at discrete frequencies can result from a coupling between tip vortex disturbances and oscillating sheet cavitation. Vortex breakdown phenomena that have some commonalities are also noted, as are some differences with vortex breakdown in fully wetted flow. Simple vortex models can sometimes be used to describe the cavitation process in complex turbulent flows such as bluff body wakes and in plug valves. Although a vortex model for cavitation in jets does not exist, the mechanism of inception appears to be related to the process of vortex pairing. The pairing process can produce negative peaks in pressure that can exceed the rms value by a factor of ten, sometimes exceeding the dynamic pressure by a factor of two. A new and important issue is that cavitation is not only induced in vortical structures but is also a mechanism for vorticity generation.

Prediction Of Natural Gas Hydrate Formation Conditions In The Presence Of Methanol Using The Trebble-Bishnoi Equation Of State

Abstract A methodology for calculating the inhibiting effect of methanol on the formation of gas hydrates in natural gas-water systems is presented. The vapor and liquid phases are modeled using the Trebble-Bishnoi equation of state. The van de Waals-Platteeuw model is used for the solid hydrate phase. In addition to the prediction of the incipient hydrate forming conditions, the compositions of the equilibrium phases are calculated. The predictions agree very well with the available experimental data. The methodology is useful in calculating the amount of methanol required to achieve a desired inhibiting effect, and the amount of methanol carried in the vapor and liquid phases. Introduction Water molecules through hydrogen bonding form a lattice-like structure with cavities. This structure known as empty hydrate lattice is unstable. However, in the presence of natural gas components with molecular diameters smaller than the diameter of the cavities, the structure can become stable. The resulting ice-like crystalline material is known as the gas hydrate. Gas hydrates are non-stoichiometric and are formed in two cubic structures, labeled I and II. Low temperatures and relatively high pressures are in general favorable for hydrate formation. Detailed information on the physical and structural properties of gas hydrates can be found in the literature(1–3), Hammerschmidt(4) showed that the blocking of natural gas transportation lines could result due to hydrate formation. The hydrates could also plug process-piping, valves, orffice plates and other gas processing facilities. It is a common industrial practice to use inhibiting agents to prevent the hydrate formation(5). Electrolytes and alcohols such as methanol and glycols are known to suppress the formation of hydrates. Experimental studies on the inhibition effects of electrolytes have been carried out by Knox et al.(6), Menten et al.(7), Roo et al.(8) and Kubola et al.(9). Experimental data on the depression effect of methanol on cyclopropane hydrate formation have been reported by Menten et al.(7). A systematic experimental study on the effects of methanol and glycols on the hydrate formation from natural gas components and their mixtures has been carried out by Robinson and his co-workers(10–13). For designing gas processing facilities, however, it is very important to have available reliable methods for calculating the depression effects and the amount of inhibitors required. Englezos and Bishnoi(15) recently formulated a computer implementable methodology for calculating the effects of single or mixed electrolytes on gas hydrate formation. The methodology uses thermodynamic models for the calculations. For calculating the depression effects of alcohols and the amounts of alcohols required, the method of Hammerschmidt(4) is widely used in the industry. The method is empirical and the reliability of the calculations is variable(14). Hence, it is desirable to develop reliable methodologies which are based on thermodynamic models and have true predictive capabilities. Anderson and Prausnitz(16) presented a thermodynamics-based method for calculating the inhibiting effects of methanol. They used van der Waals-Plarteeuw model(17) for the solid hydrate phase, Redlich-Kwong equation of state(18) for the vapor phase and the UNIQUAC model for the liquid phase.

Controlling the Flow: A Look at the Valve Lineup

By definition, a valve is a device that controls the flow of liquid or gas. Today's valves can control not only the flow, but the rate, the volume, the pressure, or the direction of liquids, gases, slurries, or dry materials through a pipeline, chute, or similar passageway. This article provides a basic overview of a number of types of valves, including gate, globe, pinch, diaphragm, needle, plug, ball, butterfly, check, relief, and control valves. Simple drawings show the working of the valves and flow through them. Tips for valve selection and maintenance and repair requirements are given.

Mixture Strength Measurements in the Combustion Chamber of SI Engine via Rayleigh Scattering. (5th Report, Concentration Profiles near the spark Plug and Intake Valves in s Steady Flow Test).

Extensive measurements were made of the fuel vapor concentration profiles near the spark plug and intake valves of a spark ignition engine during the intake stroke via the application of laser Rayleigh scattering, which can give an accurate measurement of the fuel vapor concentration with highly spatial and temporal resolutions. The mixture formation in the combustion chamber was simulated by the continuous injection of Freon-12 into the steady dust-free dry air flow through an intake port. The experimental results showed that the present experimental apparatus was effective for performing detailed measurements of the fuel vapor concentration and its fluctuation accurately near the spark plug and intake valves. It was also noted that the stereoscopic spatial distributions of the mixture strength can be derived from the experimental results. The concentration profiles near the spark plug and intake valves were largely affected by the intake valve lift and its configuration.

An experimental study on control valve cavitation. (1st report Diagnostics of cavitation vibration at high pressure reduction and at low valve opening)

Variable area cage, contoureed plug and multi-hole cage valves are tested over a range of pressure reduction from 0.1 to 5 MPa. The valve size is almost 100 in Cv value. Acceleration data at the wall are analyzed in the frequency range over 100 kHz, introducing the following representations: ( a ) Rice frequency as a center frequency to find the incipience, and ( b ) spectrum amplification to determine the critical stage. The choking is determined by the data of pressure fluctuations in the pipe. The three limits show a power law correlation between the cavitation number and the discharge coefficient. Cavitation pictures taken at a low pressure condition are also presented for the clarification of the bubble configurations.

New plug valves with downstream venting to atmosphere

New plug valves with downstream venting to atmosphere

Kinematic error in the machining of the conical surfaces of plug valves

Kinematic error in the machining of the conical surfaces of plug valves

New sealing grease for main gas pipeline plug valves

New sealing grease for main gas pipeline plug valves

How to determine comparative reliability criteria of wellhead plug valves and wedge valves

How to determine comparative reliability criteria of wellhead plug valves and wedge valves

Installation for determining the reliability of oil well shutoff plug valves

Installation for determining the reliability of oil well shutoff plug valves

Investigation of reseating process in tapered plug valves

Investigation of reseating process in tapered plug valves

37. How to select and specify process pumps: J K Jacobs,Hydrocarbon Process Petrol Refiner, 44 (6), 1965, 122–138

The piping and instrumentation diagram (PID or P&ID) shows the engineering details of the process equipment, instruments, valves, actuators, shared display devices, piping and fittings; and their arrangement. The ISA-5.1 symbols and nomenclature for P&I diagrams is explained and examples are given. The principles of operation of gate valves, globe valves, plug valves, ball valves, diaphragm valves, butterfly valves and relief valves are described. Calculation of pressure drop in pipelines and process equipment is reviewed for Newtonian, non-Newtonian and two-phase flows. The design and selection of compressors and pumps should be treated as part of the design of a hydraulic system that also comprises the equipment, piping and associated valves and fittings, and the pump and valve must be designed together to guarantee operability over the desired range of control. Mechanical design of piping under the ASME B31.3 code is introduced and a method is given for selecting the optimal pipe diameter. An overview of basic control schemes for typical unit operations is given, including level control, pressure control, flow control, ratio control, cascade control, reboiler control, condenser control, distillation column control and reactor control. The purpose and placement of alarms is discussed. A brief overview is given of current topics in advanced digital control and process automation

POWELL Lubricated Plug VALVES

POWELL Lubricated Plug VALVES