Torque Characteristics of a 122-Centimeter Butterfly Valve With a Hydro/Pneumatic Actuator

1981 ◽  
Vol 103 (3) ◽  
pp. 396-404 ◽  
Author(s):  
F. N. Lin ◽  
W. I. Moore ◽  
F. E. Lundy
Keyword(s):  
Hydraulic Resistance ◽  
Flow Resistance ◽  
Field Testing ◽  
Hydraulic Cylinder ◽  
The Other ◽  
Pneumatic Actuator ◽  
Butterfly Valve ◽  
Hydraulic Flow ◽  
Resistance Torque ◽  
Valve Opening

Actuating torque data from field testing of a 122-centimeter (48 in.) butterfly valve with a hydro/pneumatic actuator is presented. The hydraulic cylinder functions as either a forward or a reverse brake. Its resistance torque increases when the valve speeds up and decreases when the valve slows down. A reduction of flow resistance in the hydraulic flow path from one end of the hydraulic cylinder to the other will effectively reduce the hydraulic resistance torque and hence increase the actuating torque. The sum of hydrodynamic and friction torques (combined resistance torque) of a butterfly valve is a function of valve opening time. An increase in the pneumatic actuating pressure will result in a decrease in both the combined resistance torque and the actuator opening torque; however, it does shorten the valve opening time. As the pneumatic pressure increases, the valve opening time for a given configuration approaches an asymptotical value.

scholarly journals Comparative analysis of regulating characteristics between air-ring flow regulating valve and center butterfly valve

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251943
Author(s):  
Shixian Wu ◽  
Heqing Liu ◽  
Yongping Chen
Keyword(s):  
Flow Resistance ◽  
Flow Characteristics ◽  
Maximum Velocity ◽  
Experimental System ◽  
Resistance Coefficient ◽  
Flow Coefficient ◽  
Pipeline System ◽  
Butterfly Valve ◽  
Abrasive Erosion ◽  
Valve Opening

In this study, a novel air-ring flow regulating valve was proposed to reduce the flow resistance caused by valve structural pressure drop in fluid transportation pipeline system. The regulating characteristics at different valve openings were analyzed by numerical method and the results were compared with the center butterfly valve which is most widely applied in fluid transportation pipeline system. Besides, an experimental system was designed to validate the numerical model in the present study. The results indicated that the simulation results agree well with experimental data. The resistance coefficient of the air-ring flow regulating valve is smaller than that of the center butterfly valve when the valve opening is greater than 67%, and the resistance coefficient is reduced by up to 100% as the valve is fully opened. Both valves maintain approximately equal percentage flow characteristics, the deviation in relative flow coefficient is small. In addition, the wall shear stress of the air-ring flow regulating valve is much smaller than that of the center butterfly valve at the same valve opening, and the maximum velocity in the pipeline system is always smaller than that of the center butterfly valve, which significantly reduces valve surface abrasive erosion and thus prolongs its service life.

Analysis of Flow Resistance Influence on Step-Down Process of the Control Rod Hydraulic Drive System

2021 ◽  
Author(s):  
Linqing Yang ◽  
Benke Qin ◽  
Hanliang Bo
Keyword(s):  
Theoretical Model ◽  
Flow Resistance ◽  
Inflection Point ◽  
Great Influence ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Drive System ◽  
Pressure Curve ◽  
Control Rod ◽  
Step Down

Abstract Control rod hydraulic drive system (CRHDS) is a new type of built-in control rod drive technology which is invented by INET, Tsinghua University. The integrated valve (IV) is the main flow control component of the CRHDS. Flow resistance of IV has a great influence on the control rod dynamic step-down process. The step-down performance experiments of CRHDS with different flow resistance of IV were conducted under room temperature conditions. Meanwhile, the theoretical model of hydraulic cylinder step-down process was established and combined with the relationship of the flow resistance of IV under the experimental conditions to get the dynamic response of the hydraulic cylinder. The calculation results of theoretical model agree well with the experimental data. On this basis, the theoretical model of hydraulic cylinder step-down process was applied to the high temperature working conditions with different flow resistance of IV. The analysis results show that at higher working temperature, with the increase of the flow resistance of IV control rod step-down average velocity decreases and step-down time increases correspondingly. There is an inflection point in the transient pressure curve and the pressure of the inflection point decreases gradually with the increase of the flow resistance. The pressure lag time after step-down also decreases. The research results lay the base for the design and optimization of the flow resistance of the IV for the CRHDS.

Numerical Simulation and Experimental Research of a New Butterfly Valve

2012 ◽  
Vol 212-213 ◽  
pp. 1255-1260 ◽  
Author(s):  
Yang Wang ◽  
Ying Zhu ◽  
Xin Rong Shen ◽  
Jian Feng Ma
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Linear Relationship ◽  
Experimental Research ◽  
Three Dimensional ◽  
Flow Coefficient ◽  
Butterfly Valve ◽  
Valve Opening ◽  
Research And Design ◽  
Relative Flow

The paper proposes an idea of projection weighted area in designing a new control butterfly valve. A lot of three-dimensional numerical simulations are carried out on the new valve, and the numerical simulations give a good linear relationship between relative flow coefficient and relative valve opening. An experiment setup was established to verify the results of numerical simulations, and the results show that the CFD technology to research and design the new valve plate is entirely feasible.

The Parametric Modeling of Local Resistance and Pressure Drop in a Rotary Ball Valve

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Dan Wang ◽  
Changqing Bai
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Analytical Formula ◽  
Resistance Coefficient ◽  
Parametric Modeling ◽  
Equivalent Model ◽  
Local Resistance ◽  
Operating Process ◽  
Valve Opening ◽  
Good Agreement

In this paper, a theoretical study of ball valves is carried out for investigating the local resistance and pressure drop of ball valves in operating process. An equivalent model of ball valves is proposed based on the inherent mechanism of the resistance loss, which can be divided into three equivalent throttling components: a thick orifice, two variable-opening eccentric orifice plates, and a Z type elbow. Through analysis of the flow resistance of the three components, a general parametric modeling of ball valves is presented for the flow resistance analysis, and then an analytical formula of pressure drop is demonstrated. The results obtained from the presented model are compared with the prior test data to validate this model, and good agreement is observed. Indicate that the presented model has high accuracy in predicting the resistance and pressure loss in various openings. The results show that the influences of thin orifice plates play an important role in the total flow resistance coefficient and pressure drop, especially in the small opening. The effects of thick orifice plates and the Z type elbow gradually increased as the valve opening rises and becomes significant when the opening is more than 70%.

Lumped Modeling of Crosstalk Behavior of Thermal Inkjet Print Heads

2004 ◽  
Author(s):  
You-Seop Lee ◽  
Min Soo Kim ◽  
Seung Joo Shin ◽  
Suho Shin ◽  
Keon Kuk ◽  
...  
Keyword(s):  
Flow Resistance ◽  
Electronic Circuit ◽  
Circuit Simulation ◽  
Design Tool ◽  
Simulation Tool ◽  
Lumped Model ◽  
Hydraulic Flow ◽  
Thermally Driven ◽  
Flow Pressure ◽  
Electronic Circuit Simulation

This paper presents a lumped model to predict crosstalk characteristics of thermally driven inkjet print heads. The model is based on a heat conduction equation, an empirical pressure-temperature equation, and a nonlinear hydraulic flow-pressure equation. It has been simulated through the construction of a Kirchhoffian R-L-C network, and subsequently analyzed using SIMULINK and an electronic circuit simulation tool. Using the lumped R-C model, heating characteristics of the head are predicted to be in agreement with IR temperature measurements. The inter-channel crosstalk is simulated using the lumped R-L network. The values of viscous flow resistance, R and flow inertance, L of the inter-channels are adjusted to accord with the 3-D numerical simulation results of three adjacent jets. The crosstalk behaviors of a back shooter head as well as a top shooter head have been investigated. Predictions of the proposed lumped model of the meniscus oscillations are consistent with numerical simulations. Comparison of the lumped model with experimental results identifies that abnormal two-drop ejection phenomena are related to the increased meniscus oscillations because of the more severe crosstalk effects at higher printing speeds. Our model can be used as a design tool for a better design of thermal inkjet print heads to minimize crosstalk effects.

Study of Mechanism for Wear Adjustment with Electro Wedge Brake

2014 ◽  
Vol 625 ◽  
pp. 712-716 ◽  
Author(s):  
Dong Hwan Shin ◽  
Tae Sang Park ◽  
Sung Ho Jin ◽  
Jeon Il Moon ◽  
Seung Han Yang
Keyword(s):  
Cost Effective ◽  
Hydraulic Cylinder ◽  
The Other ◽  
Brake System ◽  
Sensors And Actuators ◽  
Uniform Distance ◽  
Adjustment Mechanism ◽  
Hydraulic Brake ◽  
A Chain ◽  
Gap Sensors

Electro wedge brake (EWB) have been suggested and improved for enhancing the braking efficiency and reducing the weight and power of actuating motor than electro mechanical brake (EMB). This is due to self-reinforcement features of the wedge mechanism. On the other hand, the conventional hydraulic brake system has the passive wear adjustment without any sensors and actuators. This is because of the sealing rubber which is disposed between the hydraulic cylinder and piston, and supply the piston’s same restoring strokes regardless of pad’s wear amounts. This feature leads to the uniform distance between the disc and the pad. In comparison, electronic brake systems such as EMB and EWB don’t have the hydraulic piston and cylinder with the sealing rubber. Therefore the electronic brake systems cannot use the function of this passive wear adjustment. However, if the electronic brake system has gap sensors for detecting distances between the pad and the disc, and actuators for keeping the uniform distances between the pad and the disc, then the brake system can have the function of wear adjustments. One of our research goals is the embodiment of cost-effective and feasible wear adjustment mechanism which is proper to EWB. In this paper, as a chain of EWB’s development, we describe the proposed mechanism for wear adjustment with EWB. Further we describe the feasibility of this mechanism with the simulation study.

Durable Timing Devices for the Peanut Grading Screen Vibrator1

2003 ◽  
Vol 30 (2) ◽  
pp. 92-94
Author(s):  
H. T. Sheppard ◽  
P. D. Blankenship
Keyword(s):  
Solid State ◽  
Field Testing ◽  
The Other ◽  
Durability Testing ◽  
Value Determination ◽  
State Relay ◽  
Mechanical Timer

Abstract Peanuts are graded at farmer marketing for value determination. The grading procedure requires kernel sizing which is facilitated with perforated screens oscillated with a mechanical vibrator. The vibrator operates for 20-sec periods and is controlled by a hand-adjustable, mechanical timer. The durability of the timer is unsatisfactory and it frequently fails during a single grading season. Subsequent maintenance and replacement costs prompted the development of two more durable timing units. Solid state timers were utilized in both units. Construction of the two units was the same except a mechanical relay was used for switching in one but a solid state relay in the other. During durability testing, a prototype timing device with a mechanical relay switched on and off 11,020 times over an 8-d period before failing. A timing device with a solid state relay switched on and off 68,621 times over a 22-d period without failing. During field testing, six timing units with mechanical relays and five timing units with solid state relays operated an estimated 6000 cycles each at peanut buying points throughout a peanut harvest season without failure.

Structure Optimization Design of Axial Flow Check Valve

2013 ◽  
Vol 331 ◽  
pp. 124-128
Author(s):  
Hua Shan Su ◽  
Guo Lai Yang ◽  
Li Qiang Zhang ◽  
Min Ying Xu ◽  
Ren Nian Li
Keyword(s):  
Optimization Design ◽  
Flow Resistance ◽  
Axial Flow ◽  
Check Valve ◽  
Structure Optimization ◽  
Whole Process ◽  
Valve Structure ◽  
Improved Stability ◽  
Valve Opening ◽  
Motion Characteristics

In order to enhance the performance of axial flow check valve, the nozzle and disk structures are improved. Contrast four different kinds of valve structure by CFD and get the valve structure of minimum flow resistance. By UDF and dynamic grid technology the whole process of the valve opening is simulated and the motion characteristics of the valve are achieved. It can verify the dynamic characteristic of the valve is improved, and the relative error is less than 2%. By analyzing dynamic characteristics of different inlet pressure, the axial flow check valve with optimized structure has reduced flow resistance, improved stability and longer service life.

Effects of Hydraulic Resistance Strength Training on Isokinetic Measures of Leg Strength in Men with Mental Retardation

1995 ◽  
Vol 12 (4) ◽  
pp. 377-387 ◽  
Author(s):  
Rory Suomi ◽  
Paul R. Surburg ◽  
Peter Lecius
Keyword(s):  
Mental Retardation ◽  
Hydraulic Resistance ◽  
Peak Torque ◽  
Knee Extension ◽  
The Other ◽  
Isokinetic Strength ◽  
Total Work ◽  
Trained Subjects ◽  
Leg Strength ◽  
Hip Abduction

The purpose of this study was to determine the effects of hydraulic resistance (HR) training on total work and peak torque measures of isokinetic strength for tests of knee extension and hip abduction on men with mental retardation (MR). The subjects, 22 men with mild to moderate MR, were randomly assigned to two groups; 11 subjects trained three times a week for 12 weeks using HR exercise machines, while the other 11 served as controls. Prior to and after the 12 weeks of training, all subjects were assessed on isokinetic tests of knee extension at 60 deg/s and hip abduction at 30 deg/s. The strength trained subjects exhibited significant increases in total work scores on knee extension and hip abduction tests for both legs ranging from 25.0 to 177.1%. Significant increases ranging from 50.1 to 82.7% were also noted on two of the four peak torque measures. The control subjects did not exhibit significant changes in total work or peak torque scores on either muscle test between test sessions.

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