Valve Body Research Articles

Research of Vibration Effects on a Hydraulic Valve in the Pressure Pulsation Spectrum Analysis

This paper identifies mechanical vibrations occurring in the operating environment of hydraulic systems used in marine engineering. Particular attention was paid to the influence of periodic vibrations on changes in the amplitude-frequency spectrum in a marine hydraulic system. For the case of analysing the effect of vibration on changes in the pressure pulsation spectrum with a proportional directional valve, a modified mathematical model was used. Experimental results were presented and compared with the results obtained from the mathematical model. A way of limiting the transmission of vibrations to the directional control valve body was proposed.

Boring rod for simultaneous boring of seats under the saddles of the direct-flow valve body

Issues related to achieving the required accuracy and roughness of the seats under the saddles of the directflow valve body with their high productivity are considered. For this purpose, a boring bar is been developed for the simultaneous processing of two opposite seats, protected by a author certificate. It is established that when using a hydraulic boring bar, the accuracy of the size between the seats is achieved automatically with a two-fold reduction in the main technological time. Keywords: accuracy, roughness, gate valve, boring bar, boring, productivity. tk_xt2001@mail.ru

Study on the design of ball valve based on elastic ring valve seat structure and fluid characteristics and fatigue strength

Aimed at the technical problems such as the influence of granular medium on spring pre-tightening force sealing, a new ball valve based on elastic ring valve seat structure is studied. The spring plate type valve seat structure is designed to cooperate with the ball core for sealing, and the blade spring coil is used to cooperate with the ball core for sealing in the spring plate type valve seat structure. Wherein the supporting back ring supports the blade leaf spring on the outer side to enhance and protect the role of the blade spring coil. The design without the spring cavity avoids the problem of sealing failure caused by medium entering into the spring cavity and affecting the compression spring, and avoids the situation that the valve seat can be sealed with the ball core by pre-tightening the compression spring, thus avoiding the problem of sealing failure caused by the valve seat sticking on the valve body. The mechanical and flow characteristics are studied and analyzed by the ball valve characteristic test system. The stem torque, unbalance torque, flow characteristics and flow coefficient variation at different nominal diameters are analyzed. The seal allowable squeeze stress and seal surface pressure are analyzed, and the seal is stable and reliable with the seal pressure meeting the seal design criteria. The fluid dynamics simulation analyzes the velocity, pressure and flow traces of the fluid flowing through the ball valve under three opening degrees: fully closed, half open and fully open, the maximum velocity-pressure and opening degree variation curves of the inlet and outlet, the maximum velocity-pressure and opening degree variation curves of the inlet and outlet under different nominal diameters and the flow resistance coefficient curves. Static strength analysis was done for the ball core and spring plate seat structure to obtain the stress, displacement, strain and safety factor. The fatigue strength of the ball spool and spring-loaded plate seat structure was analyzed, and the total number of lives (cycles) and load factors were obtained, and the results show that the fatigue strength of the ball spool and spring-loaded plate seat structure is safe and the fatigue strength meets the requirements. Ball valve pressure test, low pressure sealing test and high pressure sealing test, valve body strength and ball valve sealing performance all meet the requirements.

Significance of Internal Nasal Valve and Nasal Septal Swell Body in Improving the Outcome of Septoplasty: A Literature Review

Nasal obstruction is a common presenting symptom for both primary care physicians and otolaryngologists, and it can be caused by various anatomic, physiologic, and pathophysiologic factors. Structural nasal obstruction may result from a Deviated Nasal Septum (DNS), Internal Nasal Valve (INV) obstruction, External Nasal Valve (ENV) obstruction, inferior turbinate hypertrophy, Nasal Septal Swell Body (NSB) etc. Combined causes occasionally go unnoticed, and postoperative symptom relief may not always be satisfactory. Revision surgeries in cases where septoplasty fails due to misdiagnosed multicausative factors can increase the complexity of the procedure, further affecting its success. In this review, our objective is to examine the significance of the NSB and the INV, which are often overlooked nasal structures, in improving the outcomes of septoplasty. Upon reviewing the findings, it can be confirmed that diagnosing these overlooked structures has led to improved outcomes in septoplasty and, consequently, the quality of life for patients with nasal obstruction.

Research on Honing Technology of Valve Core Hole of Excavator Valve Body

This paper introduces the whole process flow of the valve core hole of excavator, and makes a deep study on the problem of the valve core hole size exceeding tolerance during the trial production, and finds the key factors that affect the quality of the valve core hole, by Means of tool adjustment and program improvement, the problem of machining valve core hole of excavator valve body is solved, and the qualified excavator valve body is manufactured successfully.

Establishment of Mathematical Model of Different Burr Removal Methods for Automobile Valve Body Parts

In the process of auto body parts processing, machining surface at the junction will produce burrs or flares. The existence of burr will have a bad effect on the machining accuracy, assembly accuracy and appearance quality of parts. In industrial production, the cost of removing these burrs is enormous. In automotive parts, the cost of deburring body parts can account for machining costs15% - 20%. Industry practice has shown that the actual cost of deburring systems increases as the complexity and accuracy of parts increase. Precision parts such as automobile valve body require high precision, and burr is usually removed by grinding. In grinding process, different types of burr will adopt different grinding process to purify, frequent adjustment process will affect the production efficiency, so the combination with the characteristics of grinding, the grinding grain edge radius, equivalent negative rake Angle and other factors into consideration, burr types can be divided into three categories, respectively on the three types of burr mathematical modeling, The removal mechanism of different kinds of burr is explained theoretically, which lays a theoretical foundation for improving efficiency in production practice.

Разработка и сертификация летной годности современной ответственной детали корпуса переключателя для аэрокосмических систем, изготовленной из сплава AlSi10Mg с помощью аддитивной технологии

Aerospace applications can benefit from additive manufacturing (AM), which is highly advantageous for prototyping and rapid manufacturing. It also offers cost and weight savings, as well as integrated design capabilities. As of now, there are only a few AM standards available, many materials and equipment are involved, resulting in many variables that hinder certification and adoption. As a result, nonstandard testing is making AM in the airborne materials less appealing due to its costly and time-consuming nature. The main objective of this work is to manufacture the Selector Valve Body parts of military and civil aircraft through Laser Powder Bed Fusion (LPBF) process using AlSi10Mg powder. Further, this paper has been carried out the metallurgical properties, non-destructive and destructive testing as well as the clear explanation about the certification procedures. Moreover, this underscores the need for the developing guidelines and standards that cover all aspects of manufacturing from design to manufacturing to operation. A comprehensive analysis from liquid penetration test shows defects are within the permissible level. In addition, it exhibits higher yield strength, ultimate strength, and elongation of (259±4), (323±4) MPa, and (12.5±1.5) % respectively, along with factual evidence that the precipitation hardened AlSi10Mg indigenously developed and produced is equal in properties to the equivalent precipitation hardening aluminium alloys produced by internationally renowned manufacturers.

The effect of obtaining the workpiece and its accuracy on the quality of the resulting part

This article describes the effect of the method of obtaining the workpiece on the quality of the part. The method of pressure treatment was considered in more detail. Its positive and negative sides are revealed, as well as its most important indicators affecting the workpiece. Using the example of the «Pneumatic valve body» part, the preparation of the workpiece and the effect of the method of obtaining the workpiece on the quality and accuracy of the part are shown in detail. The criteria and characteristics of the workpiece are also listed with the calculation of the necessary parameters. The research is carried out at the Department of «Mechanical Engineering Technologies» of the Bauman Moscow State Technical University

Research on Precise Flow Control and Anti-interference Performance of Load Sensitive Multi-way Valve with After-valve Compensation

Regarding a load-sensitive system with after-valve compensation, in the case of a single action or composite action, theoretically, the flow of each channel neither varies with the load pressure of this channel, nor is it affected by the flow of other channels, and the anti-interference performance is good. In fact, due to the influence of factors such as the flow passage of the valve body, the matching between the pressure compensation valve and the main spool, its flow control and anti-interference performance are difficult to achieve good results, which has a great impact on the synchronization, rapid action impact and micro motion characteristics of the main engine of construction machinery. This paper studies the simplification and analysis of the system pressure drop diagram, the matching characteristics between the pressure compensation valve and the main valve, accurate modeling and simulation technology, solves the problems of flow fine control and anti-interference performance, improves the flow control accuracy of a single action and compound action, and enhances the anti-interference performance. The real vehicle test shows that the self-developed multi-way valve for compensating for load sensitivity behind the valve is installed on the 6T small excavation. The initial position of the excavator’s track is aligned along a straight line. After the test runs for 20 meters, the track offset is measured. The fast forward offset is only 20mm, and the slow forward offset is only 7mm.

Modelling and Experimental Verification of the Interaction in a Hydraulic Directional Control Valve Spool Pair

This study examined the impact of mechanical oscillation on a hydraulic directional control valve. Particular attention was paid to the oscillating movement of the spool of the hydraulic directional control valve resulting from this impact. Different models of fluid and mixed friction were considered. The models analysed accounted for the relative movement of the directional control valve body and the fact that it is kinematically excited by external mechanical oscillations. It was observed that the mixed friction model, where the frictional force is considered to be the sum of molecular forces acting in micro-areas of contact and drag forces in the fluid, was the best for describing the movement of the spool for a specific spool oscillation frequency. This model yielded significantly more consistency between the simulated and experimental results than the classic fluid friction model.

Determination of the cause of destruction of the check valve body of the downhole equipment

The article provides the results of studies to determine the causes of failure of the check valve body. The fracture analysis of fractures resulting from the formation of cracks on the body of the check valve is described, with the determination of the fracture site. Also, based on the data of the process documentation for the check valve, an analysis was carried out on the manufacture, heat treatment and mechanical properties of the material of the check valve body. As a result of studies, possible defects obtained both as a result of valve operation and during manufacture as a result of heat treatment of the valve body material are determined, the microstructure of the main metal of the valve body, the results of mechanical tests, the causes of destruction are considered. In the structural elements of the tubing string (tubing) there are defects that cause their failures. For example, a fracture of the pipe body or nipple end occurs during corrosion-sorption cracking of steel, sulfide cracking in a hydrogen sulfide-containing aqueous medium; failure of the wall integrity during corrosion-sorption mechanical wear; disturbance of thread turns during fretting corrosion and cracking of steel; narrowing of internal section due to formation of solid deposits. Influence of mode of heat treatment of metal of check valve body and working loads, under conditions of complex stressed state, creates considerable concentration of stresses in area of thread hollows and corrosive sores of metal of check valve body, which in case of short-term action of inducing hydrogen sulfide-containing working medium leads to development of microcracks and destruction of metal of check valve body.

Numerical Simulation of Temperature Field in Ultra-Narrow Arc Welding of Thick-Walled Steam Turbine Valve Body Material

The welding problems of large and thick plates are becoming more prominent as the application of large-scale and thick-plate metal structures grows. Due to the issue of excessive welding deformation between the 60mm thick steam turbine valve body and the pipe joint, a new process method is employed to connect. In this paper, the welding technology of flux strip confined arc ultra-narrow gap is proposed to carry out welding test on the ZG13Cr9Mo2Co1NiVNbNB cast steel test block of steam turbine valve body material with a thickness of 60 mm. The welding temperature field is measured by means of a K-type thermocouple and numerical simulation. The results show that the thermal cycle curve obtained by the homogeneous body heat source simulation is basically consistent with the thermal cycle curve measured during the experiment, and the simulation results of the molten pool morphology are also consistent with the actual macroscopic morphology of the weld.

Numerical simulation, experiment, and optimization of a multidirectional die forging process for oil cutoff valves

An oil cutoff valve is mostly used in the petrochemical industry, playing a role in emergency cutoff. In accordance with the shape characteristics of forgings, a multidirectional die forging process for oil cutoff valves was designed in this study. Deform software was used to simulate the forging process; and the distribution laws of the deformation process, temperature, strain, stress, dynamic recrystallization, forging load, and damage were systematically analyzed. Temperature, speed, and friction coefficient were optimized by regarding the punch force and forging damage values as evaluation indexes. Results show that the optimum process parameters are used in forging production and the developed forging exhibits good forming quality. The forming test proves that the forging is completely formed without evident defects under the optimized process parameters. Moreover, its mechanical properties meet product requirements, providing theoretical guidance for a multidirectional die forging process for valve bodies.

Design and Testing of a Remote Control-Based Integrated Flow Regulation and Measurement Device

In order to maintain sustainable agriculture, the flow in irrigation systems needs to be managed remotely and finely to achieve efficient use of water resources. This research develops a flow measuring device that integrates measurement and control to achieve precise flow regulation under remote control. The device chooses the angular regulating valve as the actuation component to control the flow. By the experimental study of the valve body working characteristics, this paper (1) establishes the relationships among the pressure in front of the valve, the valve body opening and the pipeline flow; (2) establishes the relationship between the valve opening degree and the number of driving pulses of the stepper motor, and (3) designs the opening decision and flow measurement software. The experiment shows that the flow coefficient of the valve body is 84.61, and there is no leakage loss when closed. It also shows that the regulation curve matches the law of fast-opening features. The established relationship and the correlation coefficient between the performance parameters and the measured value are both greater than 0.99, indicating a decent performance of fitness. In a test where the pipeline pressures were 0.10, 0.20, and 0.30 MPa, the average duration of flow regulation was 62.48 s, with a maximum overshoot of 5%, and a maximum steady-state error of 6%. The experiment also showed that the higher the pressure is, the better the regulation effect is. The flow measurement error under varied pressure is below 3%. With its simple structure, fast flow regulation time, and high accuracy, this device meets the requirements of flow management in irrigation systems. It can be used in a variety of flow rate remote monitoring and control scenarios.

Research on an Off-Chip Microvalve for Pneumatic Control in Microfluidic Chips

A compact, rapid, and portable off-chip pneumatic control valve is significant for the miniaturization and integration of external pneumatic systems for microfluidic chips. In this work, an off-chip microvalve with a high-speed electromagnetic switch actuator and a polydimethylsiloxane (PDMS) material valve body has been designed to be easily encapsulated, simulated using MATLAB/Simulink software, and tested in a micromixer. Multi-physical coupling mathematical models are developed based on the elastic deformation force of the valve membrane, the driving force of the valve core, and the fluid force in the microchannel. Two single microvalves are used to form a three-way microvalve, which can control the air pressure in a pneumatic microchannel on the microfluidic chip. The relationship between the flow–duty cycle, the flow–pressure difference of the single electromagnetic microvalve, and the load pressure of the three-way microvalve is simulated and analyzed. Sample mixing performance controlled by the proposed off-chip three-way microvalve was tested to evaluate the pneumatic control capability, and the results show that the undertaking can fully satisfy the needs of a pneumatic microfluidic chip for most applications.

Development of a mathematical model of the operation of the swab generator valve

The object of research in the work is a mathematical model of the operation of a hydrodynamic well generator of the spring-valve type. The existing problem lies in the fact that vibrating wave swabbing differs from known methods of vibrating wave influence on the near-breakout zone of the formation in its ease of execution and, as a result, a much smaller range of equipment. At the same time, its effectiveness should not be inferior to known methods because the treatment of the formation is carried out by elastic low-frequency pressure fluctuations against the background of depression on the formation. Since the swab generator valve is, in fact, a hydrodynamic well generator (HWG) of the spring-valve type, the processes of pressure fluctuations in the considered devices will be similar. However, because of the review of HWG designs, the presence of a mathematical model describing the operation of rotor-type devices, and not valve type, was revealed. Despite the fact that the mathematical model takes into account all the main factors that determine the process of the HWG piston movement, this model cannot be used to describe the operation process of the swab generator valve. Due to the absence of a pulsating flow created at the wellhead by pumping units. Taking this fact into account, as well as taking into account the compressibility of the liquid passing through the valve, a new mathematical model was developed. It describes both the process of operation of a spring-valve type HWG operating in a well on pump-compressor pipes, and the operation of a swab generator valve that is lowered into a well on a rope. Thanks to this, it is possible to obtain the parameters of the oscillating system: geometric dimensions, inertial mass of moving parts, stiffness of the spring, coefficient of viscous friction between the piston and the valve body, as well as parameters of the working fluid: pressure, flow and its rheological properties. In comparison with the similarly known technology of vibration wave impact on a formation with known HWG, it provides such advantages as a higher speed of movement and frequency of oscillations of the moving end of the spring from the identified essential parameters of the oscillating system and the working fluid of the spring (100–1000 N/mm), consumption of working liquid (10–130 m3/h), valve opening pressure (1–7 MPa). This will make it possible to calculate a helical cylindrical compression spring made of round steel for its operation in the valve of the swab generator without collision of turns.

Analysis and compensation of surface flatness of thin-walled valve body parts

Analysis and compensation of surface flatness of thin-walled valve body parts

Numerical Simulation of a Spool Valve in Gaseous Cavitation Conditions

Spool valves are subject to a deteriorated performance and noise due to the occurrence of cavitation phenomena. It is well known that cavitation effects the performance of the component and causes an unwanted noise. The noise sound levels are influenced by many parameters like geometries and opening areas. In this paper a simple valve body made in plexiglass has been tested analyzing the cavitating area in U-grooves. A dedicated test rig has been equipped with a high-speed camera to acquire images of the phenomenon. A numerical three-dimensional CFD model has been built up using the commercial code. Experimental imagines have been compared with the numerical results showing a high accuracy on the prediction of the gaseous cavitation. The numerical results allow separate examination of several distinctive flow characteristics, which show favorable consistency with experimental observation and a periodic evolution of cavitation structure.

The calculation and research of spatial angle of double deflection inclined hole parts based on the CNC milling

In this paper, the projection method, the stereographic method and the spherical map method are used to calculate the spatial angle of the parts with the oblique hole in the numerical control machining center. At the same time, the calculation principle and method of the spatial double deflection angle hole system in the numerical control machining center are studied.The projection method is used to analyze the spatial angle relation of Φ10 holes in milling. V spherical method and H spherical method are used to calculate the positioning angle and the orientation angle. The spatial angle of a valve body part in milling Φ12 space inclined hole is calculated by using the stereographic method, and the positioning angle and the orientation angle are calculated by using the V spherical graph method and the H spherical graph method.The calculation results show that the spatial angles obtained by the above methods are the same, which verifies the correctness and the feasibility of the calculation method.

Dynamic simulation of aortic valve stenosis using a lumped parameter cardiovascular system model with flow regime dependent valve pressure loss characteristics.

Valvular heart diseases are growing concern in impoverished parts of the world, such as Southern-Africa, claiming more than 31 % of total deaths related to cardiovascular diseases. The ability to model the effects of regurgitant and obstructive lesions on the valve body can assist clinicians in preparing personalised treatments. In the present work, a multi-compartment lumped parameter model of the human cardiovascular system is developed, with a newly proposed valve modelling approach which accounts for geometry and flow regime dependent pressure drops along with the valve cusp motion. The model is applied to study various degrees of aortic stenosis using typical human cardiovascular parameters. The predicted transvalvular pressure drops for the different modelling approaches are compared to typical measured mean and peak gradients found in literature for severely stenosed aortic valves. The comparison between the predicted and measured values show that the previously published valve models under predicts expected severely stenosed peak and mean transvalvular pressure drops by approximately 47% and 25% respectively, whereas the newly proposed model under predicts the peak pressure drop by 25% and over predicts mean pressure drop by 7%.