• Tribology and Lubricants
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• 제20권5호
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• pp.231-236
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• 2004

Sulfur Hexafluoride, S $F_{6}$ is widely used for leak detection and as a gaseous dielectric in transformers, condensers and circuit breakers. S $F_{6}$ gas is also effective as a cleanser in the semiconductor industry. This paper presents a numerical study of the sealing force of disk type seal in S $F_{6}$ gas safety valve. The sealing force on the disk seal is analyzed by the FEM method based on the Taguch's experimental design technique. Disk seals in S $F_{6}$ gas safety valve are designed with 9 design models based on 3 different contact length, compressive ratio and gas pressure. The calculated results of Cauchy stress and strain showed that the sealing characteristics of Teflon $^{ }$PTFE is more effective compared to that of FKM(Viton), which is related to the stiffness of the materials. And also, the contact length of the disk seal is important design parameter for sealing the S $F_{6}$ gas leakage in the safety valve.afety valve.

• 전기학회논문지
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• 제59권10호
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• pp.1770-1775
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• 2010

An acceleration life test for rubber gasket of pole transformer was performed. The Arrhenius method was applied as an accelerated degradation test. The failure mode was considered as an elongation, and the failure mechanism is counted as a heat. It is found that both the current material(NBR: Nitrile Butadiene Rubber) and recommended alternative material(HNBR: Hydrogenated Nitrile Butadiene Rubber) have the same Weibull distribution as a life characteristic. For life expectation 95% reliability level of characteristic life is used at using temperature. The test results for NBR and HNBR are 7.7 years and 28.0 years on $50^{\circ}C$ of using temperature, respectively.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.237-240
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• 2004

Sulfur Hexafluoride, SF6 is widely used for leak detection and as a gaseous dielectric in transformers, condensers and circuit breakers. SF6 gas is also effective as a cleanser in the semiconductor industry. This paper presents a numerical study of the sealing force of disk type seal in SF6 gas safety valve. The sealing force on the disk seal is analyzed by the FEM method based on the Taguch's experimental design technique. Disk seals in SF6 gas safety valve are designed with 9 design models based on 3 different contact length, compressive ratio and gas pressure. The calculated results of Cauchy stress and strain showed that the sealing characteristics of Teflon PTFE is more effective compared to that of FKM(Viton), which is related to the stiffness of the materials. And also, the contact length of the disk seal is important design parameter for sealing the SF6 gas leakage in the safety valve.

• Tribology and Lubricants
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• 제21권4호
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• pp.171-176
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• 2005

O-ring seal is an essential component in various mechanical apparatuses for a sealing of oil container and pressure vessels. This paper presents the sealing pressure and compressive contact behaviors of hi-polymer O-rings, which is made by an outer shell of FFKM material and an inner solid ring of FKM one. The contact normal pressure and its ratios are measured by experimental method with an automatic control system of the working temperature and analyzed numerically by using the non-linear Marc FEM program. The results show reasonably good agreements between the computed FEM results and measured ones when the operating temperature is kom normal temperature of $18^{\circ}C$ and a high temperature of $300^{\circ}C$ But the compared values between the computed and tested results show a little difference because of the increased temperature, which is related to the non-linear parameter of the O-ring material. Bi-polymer 0-ring shows a good contact normal stress and compression behavior for a given operation temperature and compression ratio.

• 공업화학
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• 제19권1호
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• pp.86-91
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• 2008

다양한 고무 충전제가 연료전지 스택용 가스켓의 재료로서의 적합성 및 스택체결에 있어 미치는 영향을 살펴보기 위하여, 카본블랙 및 실리카계 충전제를 사용하여 고무를 배합하였다. 이렇게 배합된 고무재료를 PEMFC (polymer electrolyte membrane fuel cell)의 구동환경을 고려하여 열과 상대유에 대한 장기평가를 실시하였다. 가스켓에 가장 요구되는 압축 영구 줄음율은, 1000 h까지의 장기평가에서도 15% 이하의 우수한 특성을 보였다. 다양한 충전제를 사용한 배합한 고무재료로 가스켓을 제작하고, 체결시 가스켓과 가스켓 사이의 밀봉력을 FEM (finite element method)을 실시하여 최소 0.2 MPa에서 최대 2.5 MPa일 것으로 예측되었다.

• 대한기계학회논문집A
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• 제35권10호
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• pp.1193-1198
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• 2011

연료전지 내의 작동유체는 폭발성을 가지고 있기 때문에 솔레노이드 밸브의 실링특성은 일반적인 시스템에 비해 매우 중요하다 할 수 있다. 하지만, 이 시스템의 경우 작동 온도가 일반적인 경우에 비해 비교적 높으며, 작동 유체의 화학적 특성 때문에 실링에 사용되는 재질은 내화학성이 뛰어나면서도 연료전지 시스템에서 요구하는 수명을 보장해야 하는 어려움이 있다. 본 연구에서는 연료전지 내에서 사용가능한 솔레노이드 밸브의 실링 특성을 확인하기 위하여, 내화학성이 뛰어난 실링용 링의 재질인 불소고무에 대한 수명을 아레니우스(Arrhenius) 관계식을 이용하여 예측하였다. 또한, 수상치환법을 이용하여 실제 제작된 연료전지용 솔레노이드 밸브가 제품으로써 충분히 사용가능함을 확인하였다.