• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.4 s.27
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• pp.267-272
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• 2006

Butterfly valves have been used for shut-off and throttling-control application in many industrial fields. Recently, they are frequently used for cooling water, oil system and ballast piping system of many larger vessels. They are especially suited for flow throttling control of heat exchangers in engine room. Measurement by the PIV(Particle Image Velocimetry) was conducted to investigate the flow characteristics of butterfly valve inserted within circular pipe. Flow behaviors such as instantaneous and time-mean velocity vectors are investigated. Furthermore, to reveal systematic performance of the butterfly valve, wall pressure was measured at 6 points along the pipe by digital manometer. As the valve position moves to the closed side, flow separation increases and persists its tendency downstream until smoothly uniform flow developed. The pressure loss is found to be about zero for the disk open angles less than 45 degrees, but is substantially increased for those larger than 60 degrees.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.725-730
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• 1998

가동중 원자력 발전소들에서는 압력격리밸브들에 대한 기술지침서 감시시험요건과 가동중 시험 규제요건을 충족시키기 위하여 누설시험을 일정 주기로 수행하고 있다. 동 주기시험은 ASME Ba&PV Code Sec. Xl IWV-3420 또는 ASME ON Code ISTC(Part 10) 4.2.2절의 운전에 부합되는 방법과 절차에 따라 이루어지도록 규정되어 있다. 이러한 주기시험의 근본 목적과 시험방법 및 절차요건에 대한 기술적 근거의 이해는 동 시험활동의 성과를 높이는데 큰 도움이 될 것임에 틀림없다. 따라서, 본 논문에서는 압력격리 밸브들에 대한 누설시험 목적 및 시험요건의 기술적 근거를 소개하였으며, 잠재적 문제점들을 도출하여 분석 검토하고 적절한 대처 방안을 제시하였다

• Journal of the KSME
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• v.18 no.2
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• pp.122-127
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• 1978

본 규정은 대한 기계학회가 공업진흥청의 의뢰를 받아 1977년도에 작성한 "압력배관 기술기준(I)" 의 부속서중의 하나로서 본 규정에서 기술수준이라고 하는것은 압력배관 기술기준(I)을 지칭하는 것이다. 분량관계로 본회에는 그의 일부로서 적용범위 및 정의와 하중에 관한 부분을 실었다. 압력배관 기술기준은 동력배관계통의 설계, 제작, 재료, 설치 및 시험에 대한 규정을 포함하고 있 다. 오랜경험에서 이들 규정은 안전밸브설비에 대해서도 합리적으로 적용할 수 있음을 보여 주었 다. 그러나 안전밸브설비의 설계가 압력배관 기술기준의 규칙을 충분하게 적용할 수 없는 경우도 있을 수 있다. 따라서 본 부록은 안전밸브설비에 기술기준의 규정을 적용하는 방법을 명백히 하 고, 또 예를 들기 위하여 준비되었으며, 설계자에서 설계지침과 별도의 설계방법을 제공한다. 다 만, 본 부록은 강제성의 규정은 아니다.의 규정은 아니다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.392-397
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• 1997

고리 2호기 주급수 차단밸브의 경우 다른 호기와는 달리 구동용 질소압력 측정스위치에 의한 닫힘 연동신호가 설치되어 있다. 이러한 연동신호는 벨브 구동용 반구내 질소 압력 스위치 "고" 오동작에 의한 밸브차단 가능성이 있으며 이 경우 질소압력스위치가 저/고 경보창에 COMMON되어 있어 원인 규명에 어려움이 있다. 또한 질소압력 스위치 고장 및 질소가스 누설시 작업수행이 어렵고 위험이 따른다. 이러한 70년대 발전소 설계의 과잉설비를 제거하므로서 최적운전과 경제성 향상에 기여할 수 있으며 아울러 유지정비의 용이성과 밸브 불시닫힘을 미연에 예방할 수 있으리라 예상된다. 이와 관련하여 발전소 계통안전성, 기기안전성을 평가한 결과 기존의 안전해석결과가 유효하며 또한 FSAR 수정없이 이러한 설비변경이 가능하다는 결론에 도달하였다.결론에 도달하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.731-736
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• 2011

A pneumatic driving solenoid valve operates pneumatic control devices by opening/closing operating flow passage when the command is given by control system for the liquid-propellant feeding system of space launch vehicle. The simulation model of pneumatic driving solenoid valve is designed with AMESim to verify the designs and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of their operating durations of valve by AMESim analysis are compared with the results of experiments. In addition, the results of internal flow simulation with FLUENT are utilized to improve the accuracy of valve-modeling. Using the model, we analyze performance of valve; opening/closing pressure, operating time on various design factors; shape of control valve seat, drainage seat, rate of sealing diameter, volume of control cavity. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditions, which shall be used in Korea Space Launch Vehicle-II.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1447-1452
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• 2012

Existing hydraulic valve meter used in industrial fields precise pressure measurement gives inconvenience in precise measurement due to manually regulated pressures. In order to improve this inconvenience, the hydraulic valve meter was designed by using automatic design program CATIA and structural analysis of the designed hydraulic valve meter was conducted and internal water leaking, stress, strain and total deformation were obtained by applying three dimensional finite element code ANSYS. These results will be provided to develop new concepts of hydraulic valve meters as fundamental data.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.4
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• pp.1-9
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• 2010

Fuel shutoff valve of a gas generator controls propellant mass flowrate of a rocket engine, by using pilot pressure and spring force. The developing fuel shutoff valve can be self sustained even though pilot pressure is removed in an actuator. Therefore, it is necessary to analyze the characteristics of the forces with respect to the opening and closing of the valve in order to evaluate its performance. In light of this, the valve has been designed to adjust the control pressure for the opening of the poppet and to determine the working fluid pressure at which the valve starts to close. This paper also has been designed dynamic model using the AMESim and predicted flow coefficient of the valve by Fluent CFD analysis. Various results from the prediction and the analysis have been compared with experiments. Finally, dynamic characteristics of the valve have been verified with experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.725-730
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• 2011

A 2-way solenoid valve regulates to maintain the pressure of ullage volume of propellant tanks when the command is given by control system for the liquid-propellant feeding system of space launch vehicle. The simulation model of solenoid valve for pressurization is designed with AMESim to verify the designs and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of their operating durations of valve by AMESim analysis are compared with the results of experiments. Using the model, we analyze performance of valve; opening/closing pressure, operating time on various design factors; shape of control valve seat, basic valve seat, rate of sealing diameter. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditions, which shall be used in Korea Space Launch Vehicle-II.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.15-24
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• 1986

Pressure trasients must deal with safety problem of system. For identification of physical situation that can and method of limiting surges are essential consideration in sucessful design. The finite difference equation by method of characteristics are derived from the governing equation of unsteady flow in a pipe, and solved by using boundary condition derived. A computer program which can simulate general hydraulic system is developed by using finite difference equations and boundary conditions derived. The sumulated resulted by developed computer program are in fair agreement with experiment result.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.108-117
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• 2013

The oxidizer shutoff valve of a gas generator controls the mass flow rate of the propellant of a rocket engine using pilot pressure and spring the force of the valve. The developing oxidizer shutoff valve can be shut off if the pilot pressure is removed from the actuator. Therefore, force balancing is necessary to analyze the characteristics of the forces with respect to the opening and closing of the valve in order to evaluate its performance. In light of this, the valve has been designed to adjust the control pressure required to open the poppet and to determine the working fluid pressure at which the valve starts to close. Under cryogenic flow test as a tests level of C.R.T(Control Random Test), the chattering phenomena occurred due to much leakage of a metal seat section. The pressure for chattering of the oxidizer valve is predicted at about 11 bar using force balancing analysis.