• 한국안전학회지
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• 제32권4호
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• pp.129-136
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• 2017

This study investigated the probability of possible accident through qualitative and quantitative analysis of the pressure safety valve types installed in facilities using high pressure gas to compare the installation domestic and foreign pressure safety valve standards sought the safety characteristics and safety improvement direction accordingly. The three types are the case where the shut-off valve is not installed at the front of the PSV (Case A), If a shut-off valve is installed at the front of the PSV for inspection (Case B) and If a shut-off valve is installed in front of PSV (C.S.O), PSV is installed in parallel (Case C). Three types of cases were compared with FTA and HAZOP. The results of study of the possible accidents due to over-pressure safety valve installation type, used in a high-pressure gas facilities was shows in the following order Case B > Case A > Case C. The results of analysis through FTA was in order to protect the reservoir for the possible occurring of accident the safety valve installation is depend on its type. In the FTA analysis, defects in the device itself which attached to the storage tank as a substitute for analysis of the probability of operator mistakes was Case B with as high as $2.01{\times}10^{-6}$. Depending on the type of installation analysis of Case B in order to ensure safety is prohibited to install shut-off valve and believes that mandatory regulations are needed. Rationally installing of pressure safety valve in the high pressure using facilities will be expected to improve the industrial safety from severe accidents such as high-pressure gas fire explosion.

• 한국가스학회지
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• 제9권3호
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• pp.44-48
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• 2005

가정용 LPG 저압조정기의 사용수명을 평가하기 위하여 실험적 연구를 수행하였다. 실험결과에 의하면 조정압력과 폐쇄압력은 사용경과 7년부터의 조정 기에서 표준값을 현저하게 벗어나는 것으로 나타났다. 따라서 이들 결과로부터 LPG 저압조정기는 약 6년 정도의 사용수명을 갖고 있는 것으로 평가된다.

• Safety and Health at Work
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• 제7권4호
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• pp.340-346
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• 2016

Background: safety and healthy working environment has received numerous research attention over the years. Majority of these researches seem to have been conducted in the construction industry, with little attention in the health sector. Nonetheless, there are couple of studies conducted in Africa that suggest pressure in hospitals. Therefore the aim of the study was to examine how pressure influence safety behavior in the hospitals. With reference to the relevance of safety behavior in primary health care delivery, there was the need for the study. Method: Data was obtained from 422 public hospital employees. Respondents were assured that all information would be kept confidential to increase the response rate and acquire more accurate information. Collection of questionnaires from participants took four weeks (20 working days), after which the data was analyzed. Results: The result of the study showed that work pressure correlated negatively with safety behavior. General safety climate significantly correlated positively with safety behavior and negatively with work pressure, although the effect size for the latter was smaller. Hierarchical regression analysis showed management commitment to safety to moderate the relationship between work pressure and safety behavior. Conclusion: When employees perceive safety communication, safety systems and training to be positive, they seem to comply with safety rules and procedures than voluntarily participate in safety activities.

• 한국안전학회지
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• 제13권2호
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• pp.104-108
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• 1998

In order to evaluate the performances of safety valves for low pressure, the popping pressure and flow rate of the natural gas have been investigated. The measured results of the popping pressure show that there is a big scattering depending on the manufacture year of a safety valve. And sample A showed the ideal popping pressure mode compared to other B and C samples. The popping flow rate of the safety valve is proportional to the seat size as the inlet pressure increases. These results may be used as a guideline for a design and diagnosis of the safety valve.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.729-734
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• 2017

안전릴리프밸브는 배관라인 혹은 탱크의 과도한 압력을 완화하고 사용 적정압력 수준으로 유지해주는 장치이다. 안전릴리프밸브는 스프링 보닛에 통풍구가 대기 쪽으로 혹은 배출구 쪽으로 뚫려 있는지에 따라 배압의 변화에 직접적으로 영향을 받게 된다. 배압은 축적 배압(Built-up back pressure)과 부과 배압(superimposed back pressure)으로 나뉘게 되며 사용조건에 따라 배압의 특성이 달라진다. 본 연구에서 사용되는 안전밸브는 Conventional Safety Relief Valve로써, 배압의 특성을 가정하였다. 또한 개방력과 스프링력 사이의 힘의 평형 방정식을 세워 이론적 접근방법으로 초기 스프링 변위를 구하였다. 디스크가 받는 반력 즉 개방력과 스프링력을 비교하여 블로우 다운을 예측하였다. 블로우 다운은 설정 압력과 디스크 재닫힘 압력 간의 차이다. 본 연구는 ASME 규격 코드에 따라서 블로우 다운 시험 전에 전산 유동해석프로그램 CFX17.1을 이용하여 수치적으로 예측하였음을 밝힌다. 또한 유체-구조 연성해석(fluid-structure interaction analysis)을 통해 안전밸브 트림부의 안전성을 검토하였다. 향후, 시험과 전산수치해석 값을 서로 비교하여 블로우 다운 이론적 접근방법과 유동해석방법을 제안하고자 한다.

• 한국안전학회지
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• 제25권5호
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• pp.7-14
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• 2010

Ultra high pressure system, which can be generally increased over 1,000bar, needs to have sealing mechanism to protect leakage and selection of the materials used in the intensifier. Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions. Components need to be tested under 1.5 to 3 times of rated pressure to check the tolerance even though rated pressure range of these components are not ultra high pressure. So, the ultra high pressure system needs to be equiped to test components. In this study, safety assessments of ultra high pressure system which are using failure analysis of components, changing the types of the control system, and finite element analysis with static condition, are investigated.

• 한국가스학회지
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• 제18권6호
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• pp.40-44
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• 2014

본 연구에서는 STS304로 만든 소형프로판용기의 내압증가에 따른 형상변화를 분석하였다. 소형 프로판용기는 내압이 증가하면 하부 경판이 아래쪽으로 볼록하게 형상이 변한다. 이러한 형상변화에 따른 소형 프로판용기의 내압의 변화를 분석하고자 기존의 내압시험과는 다른 방법인 수조식 내압 시험방법을 이용하였다. 수조식 내압시험 방법은 가압에 따른 용기의 체적변화량을 실시간으로 측정해 용기의 내압과 체적과의 관계를 분석 가능하다. 분석결과 하부 경판부의 형상변화에 따른 용기변형구간이 존재하고 용기의 하부 경판부의 변형이 시작되면 가압에 따른 부피증가량이 비례하지 않고 더 많이 증가되어 내압이 감소하는 경향을 나타낸다는 것을 확인하였다. 본 연구의 결과는 소형 프로판용기 뿐만 아니라 다양한 압력용기의 안전성 향상에 기여할 것을 기대한다.

• 한국가스학회지
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• 제21권6호
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• pp.15-22
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• 2017

안전밸브는 높은 압력을 사용하고 있는 공장들의 안전을 확보하기 위한 최후의 수단이다. 안전밸브의 고장은 대형사고로 이어지므로, 주기적으로 작동성능을 점검하도록 법으로 정해져 있다. 현재 안전밸브의 작동성능을 확인하기 위해서 직접검사방법을 이용하고 있으나 이는 검사 사각지대의 유무, 비용 및 효율적인 손실 등으로 인해 운전 중 검사 방법의 개발이 요구 되고 있는 실정이다. 본 연구에서는 안전밸브 성능검사 결과자료를 분석하여 국가 산업단지의 불안전한 안전밸브 상태를 살펴봄으로써 현재 운용 중인 직접검사법만으로는 안전성의 확보에 한계가 있음을 확인했다. 이에 따라 직접검사법의 한계를 극복하기 위하여 운전 중 검사법 도입의 필요성을 검토하고, 필수 기반 시설에의 적용을 의무화 하는 등 공정 운전 중에도 안전밸브의 검사가 가능한 방법의 개발과 관련 제도의 변화가 필요할 것으로 판단된다.

• 한국유체기계학회 논문집
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• 제10권5호
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• pp.20-26
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• 2007

Some gate valves are susceptible to pressure locking and thermal binding which prevent the safety function. The safety related gate valves susceptible to pressure locking and thermal binding shall be identified and taken preventive actions to ensure the safety function. The identification of the gate valves susceptible to pressure locking and thermal binding needs the evaluation of system design, valve and piping arrangement, test requirements, and operating conditions. Application of preventive methods should consider the system safety function, applicability, effectiveness, interface with system design, and cost. The selection procedure of valves susceptible to pressure locking and thermal binding can be effectively used in industry including nuclear power plants. In order to prevent the pressure locking, the hole can be drilled through the one disc of upstream side or down stream and the external equalizing line can be installed from bonnet to downstream or upstream. The double disc parallel seat valve type can be used instead of flexible wedge gate valve to prevent the thermal binding. The identification of gate valves susceptible to pressure locking and thermal binding, and preventive actions will meet the regulatory requirements and enhance the availability and safety of plants.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.629-636
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• 2003

The purpose of this study is localization of safety relief valves for Nuclear Service through technical development with overall design, fabrication, inspection, capacity certification test and functional qualification test of safety relief valves in accordance with ASME Section III and KEPIC Code. Safety relief valve is the important equipment used to protect the pressure vessel, the steam generator and the other pressure facility from overpressure by discharging the operating medium when the pressure of system is reaching the design pressure of the system. But we're depending on technology of the other country up to the present time. Because we don‘ have our own technologies, we have been spent the great time and money on installing and repairing safety relief valve at nuclear power plant. Therefore we have to achieve the development of safety relief valves for Nuclear Service with our own technologies.