• Journal of the Korean Institute of Gas
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• v.23 no.5
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• pp.35-43
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• 2019

The safety of industrial valves, which are the core parts of plant facilities, are managed by manpower and there are difficulties because of side area for inspection and limited accessibility due to the nature of facilities. The industrial valves used in plant facilities cause problems such as interrupted production; a loss of life due to leak or explosion of poisonous material and flammable gases, and difficulty in locating accident positions in the event of leakage or failure. Therefore, safety management and control systems based on IoT technology are needed. This study is about the development of risk factor prediction technique among the safety management of industrial valves through IoT- based wireless communication and the development of actuator control system. We have developed IoT-based industrial valve safety management techniques to prevent accidents caused by main risk factors by conducting an analysis of the structural characteristics of valves and an analysis of the causes of main risk factors through review of failure data and literature and an analysis of accident scenarios.

• Journal of the Korean Institute of Gas
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• v.11 no.1 s.34
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• pp.23-28
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• 2007

This paper presents an experimental investigation on the sealing defects and cracks of O-rings and a valve packing of a gas valve for a LPG cylinder. O-ring in which stops a gas leakage of a liquefied petroleum gas is very important for a LPG valve safety. Valve packing is to open and close a gas flow port for supplying and charging a LPG fuel. The sealing performance of two sealing units ism related to the leak safety and long lift of a gas valve. The investigated results show that most of O-rings was failed due to a circumferential crack in which is caused by partial press bonding failure near the partition zone and an excess compression rate. Some of the O-ring failure was originated by an extrusion of an excessive leak pressure of a LP gas. Thus, this paper strongly recommends a tight quality control and a safety guarantee system of O-rings and valve packing to guarantee a leak safety and to extend a service lift of a gas valve. At the end, a warranty policy of the sealing units should be adopted for increasing a product quality and safety of a gas valve.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.729-734
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• 2017

A safety relief valve is a device that relieves excessive pressure in piping lines or tanks and maintains pressure at the appropriate pressure level for use. The (pressure in the) safety valve is directly influenced by the change in the back pressure, depending on whether the vents in the spring bonnet are vented to the atmosphere or to the outlet. The back pressure is divided into the built-up back pressure and the superimposed back pressure, and the back pressure characteristics vary according to the usage conditions. The safety valve used in this study is a Conventional Safety Relief Valve. The blowdown of the safety valve is predicted by establishing the equilibrium equation between the opening force and spring force considering the back pressure characteristics. Its reliability is secured by using CFX17.1. In addition, the safety of the safety valve trim was examined through fluid-structure interaction analysis.

• Journal of the Korean Institute of Gas
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• v.11 no.2 s.35
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• pp.37-42
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• 2007

This paper presents the leakage safety of two O-rings, which are located at the rectangular groove between a valve body and a valve stem. The leakage safety analysis of 0-ring seals has been computed as functions of a compression set and a liquefied petroleum gas pressure of a LPG cylinder using a FEM program, MARC. The FEM computed results indicate that the loads from the filling pressure of $8kg/cm^2$ to the upper limit of the safety valve, $24.8kg/cm^2$ work safely according to the pressure vessel code. But two O-rings should consider the aging effects for an increased safety of the o-ring.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.70-77
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• 2011

A ventilation-relief valve performs as a safety-valve assembly for the liquid-propellant feeding system of space launch vehicle. This valve plays a role of relieving the vaporized propellants from propellant tanks during the filling and storing stages of propellants. Also it regulates to maintain the pressure of ullage volume of on-board propellant tanks within the safety-margin during the flight. The simulation model of ventilation-relief valve is designed with AMESim to predict and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of the opening and closing pressures and their operating durations of valve by AMESim analysis are compared with the results of mathematical methods. In addition, the results of internal flow simulation with FLUENT are utilized to improve the accuracy of valve-modeling. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditionss, which shall be used in Korea Space Launch Vehicle-II.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.25-33
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• 2020

In this study, flow and structural computational analysis were performed to investigate the structural safety of the lightweight butterfly valve disc designed by topology optimization. After flow analysis, as the opening angle increased, the flow coefficient increased non-linearly and showed a gentle slop. When the opening angle was 12 degree, the cavitation could be predicted. After FE analysis, all FE von-Misses stresses of the lightweight disc were smaller than the yield strength of the material, and all FE maximum deformations were also smaller than the conservative deformation of the previous study. Ultimately, it was confirmed that the structural safety of the lightweight valve disc based on computational analysis is effective.

• Journal of Aerospace System Engineering
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• v.13 no.4
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• pp.50-59
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• 2019

The design of the main control valve, which is the main component of the flap control system, was based on actual manufacturing experience on the basis of trial and error method. In this paper, a model-based part design method is proosed. The flap control system consists of a main control valve, fail-safe valve, solenoid valve, LVDT and force motor. The main control valve consists mainly of a spool and slot. The important design parameters of the main control valve are the slot width, overlap and clearance. AMESim is linked to the model and it analyzes the flow path of the main control valve. Applying the proposed design procedure, it was confirmed that the required performance was satisfied within the allowable machining error range.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.19-19
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• 2018

최근 경주, 울산, 포항 등 경상도 지역에서 잇달아 발생한 대규모 지진으로 인해 사회기반시설물의 내진 안전성이 이슈가 되고 있다. 지진 안전 국가라고 여겨지던 우리나라는 상대적으로 지진에 대한 대비가 매우 부족한 실정이며, 자칫 대규모 피해로 이어질 우려가 있다. 특히 상수관망의 경우, 지중에 매설되어 있는 특성상 지진에 취약하고, 그 피해를 발견하기 어려워 장기적인 피해가 불가피하다. 상수관로의 지진피해는 누수와 파손으로 구분할 수 있으며, 파손관의 경우 용수공급능력을 크게 저하시키기 때문에 신속한 복구가 요구된다. 파손관의 복구는 부근에 위치한 차단밸브를 닫아 피해관로의 통수를 차단한 후에 복구 작업을 진행하는 것이 일반적이다. 이때, 차단밸브의 위치에 따라 단수구역이 광범위하게 발생할 수 있어 시스템 전반의 용수공급능력 저하로 이어질 가능성이 있다. 본 연구에서는 지진 발생 후 피해관로의 효율적인 복구전략 마련을 위한 상수관망 지진피해 복구 시뮬레이션 모형을 개발하였다. 개발 모형은 피해복구에 따른 상수관망 시스템의 용수공급능력을 정량적으로 산정할 수 있으며, 지진 발생과 같은 비정상 상황의 시스템 용수공급능력을 수리학적으로 정확하게 해석하기 위해 압력기반의 해석(Pressure-driven analysis, PDA)을 적용하였다. 또한, 피해관로의 복구 시, 차단밸브에 의해 발생되는 단수구역을 탐색한 후, 수리해석 모의에 적용함으로써 현실적인 용수공급 상황을 모의할 수 있도록 하였다. 본 연구에서는 개발모형을 활용하여 차단밸브의 위치 및 개수가 단수구역의 범위 및 지진복구에 미치는 영향을 정량적으로 비교 분석하였으며, 이를 통해 효율적인 지진피해 복구 전략을 제시하였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.105-109
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• 2002

최근 빈번하게 발생되고 있는 가스사고는 많은 인명과 재산상의 손실을 초래하고 있다. 특히 도시 가스 보다는 공기보다 비중이 큰 LP가스에 의한 사고가 많이 발생된다. 특히 최근에 발생한 인천 부평구의 LP가스 폭발사고는 사망6명, 부상21명 등 총 27명의 인명피해와 주택 붕괴 등 많은 재산상의 손실을 초래하였다. 또한 LP가스 용기는 용기자체가 자해나 위해의 수단으로 이용되기도 한다. 이에 따라 정부에서는 1998년 1월 10일 고압가스안전관리법 시행규칙을 개정하여 LP가스용기에 부착되어 사용되는 밸브를 과류차단형으로 의무화하여 가스사고예방을 위해 힘쓰고 있다.(중략)

• 월간 기계설비
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• s.295
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• pp.93-95
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• 2015

지난 2013년 7월 25일 도시가스사업법 시행규칙 개정에 따라 도시가스 은폐배관 설치 시 천정에 가스누출점검을 위한 점검구를 뚫거나 값비싼 다기능가스안전계량기를 설치해야 한다. 이에따라 수많은 민원이 발생하여 대한설비건설협회(이하 협회)는 실내 미관을 위해 점검구의 크기를 축소하고, 가스누출 점검을 위한 대체방법으로 다기능가스안전계량기 뿐만 아니라 가정에서 저렴하게 설치할 수 있는 가스누출확인배관용밸브 설치도 허용해 줄 것을 건의해 왔다. 협회 건의에 대해 가스기술기준위원회는 지난 1월 27일 질의회신을 통해 가스누출확인배관용밸브 설치 시 은폐배관의 가스누출이 탐지 가능하므로 가정 내에서 이 밸브를 설치할 경우 점검구를 뚫지 않아도 된다고 회신했다.