An Investigation Into the Characteristics of a Two Dimensional “2D” Flow Control Valve

In hydraulic servo systems, a pilot stage is often used to reduce the influence of Bernoulli’s forces and frictional forces when trying to accurately position a spool. A unique pilot controlled valve (defined as a two dimensional or “2D” flow control valve), which utilizes both rotary and linear motions of a single spool, is presented. The rotary motion uses a spiral groove in the sleeve combined with high and low pressure holes on the spool land to control the pressure in the spool chamber, while the linear motion of the spool is actuated by a hydrostatic force. Both linear theory and numerical simulation are adopted in the investigation of the characteristics of the valve. A criterion for stability is established from a linearized model of the valve. The analysis establishes the effects that certain structural parameters have on the valve’s static and dynamic characteristics. Special experimental procedures were designed to obtain properties such as mechanical stiffness, leakage flow rate, and dynamic response under different structural parameters and system pressure. It was shown that the leakage through the spool-sleeve clearance had a favorable effect on the valve stability. Theoretical and experimental results show that it is necessary to establish a balance between the static and dynamic performance in establishing appropriate structural parameters. It is also shown that the 2D flow control valve can demonstrate a high speed of response, while maintaining the pilot flow rate at a low level.

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An Investigation Into the Characteristics of a “2D” Flow Control Valve

10.1115/imece2000-1984 ◽

2000 ◽

Author(s):

J. Ruan ◽

R. Burton ◽

P. Ukrainetz

Keyword(s):

Flow Control ◽

Flow Rate ◽

High Speed ◽

Structural Parameters ◽

Control Valve ◽

Favorable Effect ◽

Flow Control Valve ◽

System Pressure ◽

Hydrostatic Force ◽

2D Flow

Abstract In hydraulic servo systems, a pilot stage is often used to reduce the influence of Bernoulli’s forces and frictional forces when trying to accurately position a spool. A unique pilot controlled valve, (defined as a “2D” flow control valve), which utilizes both rotary and linear motions of a single spool, is presented. The rotary motion uses a spiral groove in the sleeve combined with high and low pressure holes on the spool land to control the pressure in the spool chamber, while the linear motion of the spool is actuated by a hydrostatic force. Both linear theory and numerical simulation are adopted in the investigation of the characteristics of the valve. A criterion for stability is established from a linearized model of the valve. The analysis establishes the effects that certain structural parameters have on the valve’s static and dynamic characteristics. Special experimental procedures were designed to obtain properties such as mechanical stiffness, leakage flow rate, and dynamic response under different structural parameters and system pressure. It was shown that the leakage through the spool-sleeve clearance had a favorable effect on the valve stability. Theoretical and experimental results show that it is necessary to establish a balance between the static and dynamic performance in establishing appropriate structural parameters. It is also shown that the 2D flow control valve can demonstrate a high speed of response, while maintaining the pilot flow rate at a low level.

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Modeling and Analysis of a Pressure Compensated Flow Control Valve

Volume 2: Fora ◽

10.1115/fedsm2005-77057 ◽

2005 ◽

Cited By ~ 3

Author(s):

Minter Cheng

Keyword(s):

Response Time ◽

Flow Control ◽

Transient Response ◽

Flow Rate ◽

Control Valve ◽

Spring Constant ◽

Flow Control Valve ◽

Hydraulic Systems ◽

System Pressure ◽

Control Accuracy

In hydraulic systems, flow control valve is used to regulate the flow of fluid to actuators by adjusting the valve opening. However, the inlet and the outlet pressures of the valve are not always remaining constant. Any change in pressure will alter the flow rate through the valve and alter the actuator speed consequently. Pressure compensated flow control valves are often used in hydraulic systems when accurate speed control is required under varying supply or load pressures. The basic structure of the pressure compensated flow control valve is by incorporating a compensating spool to maintain a constant pressure drop across the metering orifice. Under ideal circumstance, the actuator speed can be constant and controllable, regardless of load or system pressure changes. However, in practical applications, any system or load pressures variations will cause force unbalance on valve compensating spool and affect the control accuracy. The steady and dynamic response of the flow control valve plays an important role on hydraulic system behavior. Therefore, analyzing and understanding of the valve steady and dynamic behaviors is very important. In this study, the steady and dynamic performance of a pressure compensated flow valve is simulated numerically by solving the characteristic equations. The parameters studied in this research are biased spring constant, pre-compressed spring length, spool mass, and the damping orifice characteristics. The simulation results show that the flow force is identified as the key factor to affect the control accuracy. Increasing the spring constant as well as the pre-compressed spring length will increase the steady flow rate and reduce the transient response time. Decreasing the damping orifice opening or the discharge coefficient will increase the transient response time. The spool mass has practically no effect on the flow rate.

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Analysis and Modification of the Design of Fluid Power Control System for the Improvement of Product Quality

Volume 2: Reliability, Availability and Maintainability (RAM); Plant Systems, Structures, Components and Materials Issues; Simple and Combined Cycles; Advanced Energy Systems and Renewables (Wind, Solar and Geothermal); Energy Water Nexus; Thermal Hydraulics and CFD; Nuclear Plant Design, Licensing and Construction; Performance Testing and Performance Test Codes ◽

10.1115/power2013-98064 ◽

2013 ◽

Author(s):

Tahany W. Sadak ◽

Taha E. Mkawee

Keyword(s):

Flow Control ◽

Flow Rate ◽

System Performance ◽

Dynamic Performance ◽

Control Valve ◽

Operating Conditions ◽

Flow Control Valve ◽

Supply Pressure ◽

System Designs ◽

Proportional Flow

This research investigation is focused on providing system performance under different operating conditions, with special focus on variations in the supply pressure. The investigations have been carried out for different system designs. The analysis of the results introduces the effect of system designs on its static and dynamic performance. Also, the investigations provide the effect of variations of system operating conditions and load value. A hydraulic system has been designed with variable velocity, pressure and load. The detailed examination has been carried out on a system that consists of a hydraulic power supply unit, control valves (pressure control valve, flow control valve, throttle valve and directional control valve). We have investigated the effect of adding a flow control valve (FCV) in the chosen circuit and also replacing the FCV with a proportional flow control valve (PFCV). In order to study the effect of this valve on system performance we examine the role of change of operating conditions and loading values on the system performance. Thus the displacement and speed of the piston of the hydraulic cylinder has been experimented under different values of supply pressure, flow rate, and load. We make this investigation to develop the performance evaluation by replacing the (FCV) by proportional flow control valve (PFCV) via position control so that one can achieve the static and dynamic performance of the system more accurate. Apparent improvement in flow rate ranges from 8% to 29.5% and dynamic response from 30 to 64%. The results reveal that this methodology allows one to achieve high quality of the product.

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Development of Novel Particle Excitation Flow Control Valve for Stable Flow Characteristics

International Journal of Automation Technology ◽

10.20965/ijat.2016.p0540 ◽

2016 ◽

Vol 10 (4) ◽

pp. 540-548 ◽

Cited By ~ 1

Author(s):

Daisuke Hirooka ◽

◽

Tomomi Yamaguchi ◽

Naomichi Furushiro ◽

Koichi Suzumori ◽

...

Keyword(s):

Flow Control ◽

Flow Rate ◽

Flow Characteristics ◽

Control Valve ◽

Flow Control Valve ◽

Different Types ◽

Valve Opening ◽

Working Principle ◽

Stable Flow ◽

Air Flow Control

The authors have previously developed a compact, light-weight air flow control valve, which realizes continuous flow control. The vibration produced by a piezoelectric device (PZT) was used to excite particles confined in a flow channel to control the valve opening for the developed control valve. Therefore, the voltage applied to the PZT can be changed to continuously control the flow rate. A new working principle was developed for the control valve to stabilize flow rate characteristics. Different types of particles were used to change the valve opening condition. A prototype was manufactured to demonstrate the effectiveness of the control valve.

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New Designs in Fuel Dispensing System to Control Maximum Flow of Volatile Liquid

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.868.75 ◽

2017 ◽

Vol 868 ◽

pp. 75-80

Author(s):

Ya Jun Liu ◽

Shu Yan Zhan ◽

Jia Kun Ye ◽

Wen Hua Xie

Keyword(s):

Flow Control ◽

Flow Rate ◽

Oil And Gas ◽

Control Valve ◽

Maximum Flow ◽

Control Mode ◽

Theoretical Research ◽

Flow Control Valve ◽

Cavitation Phenomenon ◽

Volatile Liquid

The dispenser is a fuel pumping and measurement device used in the service station. During the refueling process of volatile liquid, the cavitation phenomenon occur easily due to the large flow rate. The serious cavitation will not only reduce the pumping efficiency, produce loud work noise, but also aggravate the pollution of oil and gas and the energy consumption of the system. Therefore, it is necessary to control the maximum flow rate of the pump. Based on this problem, this paper firstly designs a new flow control valve, and a method of mathematical modeling is proposed to analyze the flow field distribution and the working principle of the whole device based on Euler equation and Bernoulli equation. Then we combine this new hydraulic device to the variable frequency dispenser, a new design of the dispenser structure and a control mode of the maximum flow are proposed. The theoretical research shows that the maximum flow can be limited by optimizing diameter ratio of that flow control valve.

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Particle-Excitation Flow-Control Valve using Piezo Vibration-Improvement for a High Flow Rate and Research on Controllability

IEEJ Transactions on Sensors and Micromachines ◽

10.1541/ieejsmas.137.32 ◽

2017 ◽

Vol 137 (1) ◽

pp. 32-37 ◽

Cited By ~ 4

Author(s):

Daisuke Hirooka ◽

Tomomi Yamaguchi ◽

Naomichi Furushiro ◽

Koichi Suzumori ◽

Takefumi Kanda

Keyword(s):

Flow Control ◽

Flow Rate ◽

Control Valve ◽

High Flow ◽

High Flow Rate ◽

Flow Control Valve

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Diagnostics of Resistance Coefficients and Cavitation of Flow Control Valve

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.752-753.980 ◽

2015 ◽

Vol 752-753 ◽

pp. 980-987 ◽

Cited By ~ 4

Author(s):

Jana Jablonská ◽

Milada Kozubková

Keyword(s):

Flow Control ◽

Flow Rate ◽

Flow Characteristic ◽

Rate Coefficient ◽

Control Valve ◽

Flow Control Valve ◽

Flow Rate Coefficient ◽

Resistance Coefficients ◽

Valve Pressure

The paper deals with the determination of characteristic as dependence of the valve pressure drop on the flow rate, flow characteristic and cavitation conditions in case of water flow in the flow control valve. Emphasis is put on the utilization of simple, available relationships and measuring for identification of the basic valve coefficients, e.g. loss coefficient, flow rate coefficient and cavitation factor. These coefficients are used for designing of pipe circuits. In this paper there is defined methodology for determining those coefficients and is applied to the modified cone of flow control valve for verification the linear flow characteristic. It is necessary to consider the fact that in various countries the modifications of coefficients are preferred and it is therefore necessary to specify them.

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Analysis of a Pressure-Compensated Flow Control Valve

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.1870037 ◽

2004 ◽

Vol 129 (2) ◽

pp. 203-211 ◽

Cited By ~ 22

Author(s):

D. Wu ◽

R. Burton ◽

G. Schoenau ◽

D. Bitner

Keyword(s):

Pressure Drop ◽

Flow Control ◽

Flow Rate ◽

Constant Pressure ◽

Control Valve ◽

Control Device ◽

Operating Conditions ◽

Flow Control Valve ◽

Flow Control Device ◽

Linearized Model

A pressure-compensated valve (PC valve) is a type of flow control device that is a combination of a control orifice and a compensator (often called a hydrostat). The compensator orifice modulates its opening to maintain a constant pressure drop across the control orifice. In other words, the PC valve is so designed that the flow rate through the valve is governed only by the opening of the control orifice and is independent of the total pressure drop across the valve. Because of the high nonlinearities associated with this type of valve, it is impossible, in practice, to design such a valve where the flow rate is completely unaffected by the pressure drop across the valve. In this paper, the effect of the nonlinearities on the performance of the PC valve is investigated. First, a generic nonlinear model of a PC valve is developed. Using this model, all possible operating conditions can be determined. Then a linearized model is developed and used to analyze the dynamic behavior of the PC valve. The model can then be used to evaluate and improve the design and operation of the valve for specific applications.

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