• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.619-622
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• 2009

INCONEL 718합금은 상온, 고온 및 저온환경에서 기계적 특성이 아주 우수하다. 상온에서의 모재 강도는 약 900MPa이며, 열처리 후 시효경화처리에 의해 강도가 약 1300MPa까지 증가한다. 이러한 INCONEL 718합금의 기계적 특성은 시험결과에서도 유사한 값을 나타내었고, GTAW 용접부의 상온 기계적 특성도 모재보다 우수한 강도를 나타내었다. 또한 저온에서의 기계적 특성은 모든 시험조건에서 상온보다 높은 강도를 나타내었으며, 열처리 모재시편과 용접시편은 1400MPa에 달하는 고강도를 나타내었다. 이러한 결과를 바탕으로 INCONEL 718합금의 저온 기계적 특성이 우수한 것을 증명하였고, 용접성 또한 모재의 특성과 같이 상온 및 저온 특성이 우수한 것을 알 수 있었다. INCONEL 718 합금과 STS 316L의 이종접합의 경우에도 $-100^{\circ}C$환경의 인장강도가 상온보다 300MPa 이상 증가하는 것을 알 수 있었다. 따라서, INCONEL 718합금은 $100^{\circ}C$이하부터 일정온도까지는 기계적 특성이 계속 증가 할 것으로 사료되며, 극저온 고압 상태로 공급되는 산화제 배관 제작에 적합한 소재로 판단된다.

• 월간 기계설비
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• s.43
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• pp.70-75
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• 1994

한국건설방식연구소(소장 이의호)가 지난해 12월5일 건설회관에서 제1회 국제방식기술세미나를 개최, 건설업계의 관심을 모았다. 이 세미나에서 $\ulcorner$아파트 물탱크 및 수도배관의 부식과 방식$\lrcorner$에 관한 주제발표를 한 이의호 소장은 국내 아파트의 급수관이 대부분 탄소강재나 철근 콘크리트재로 만들어져 부식이 급속히 진행되고 있으므로 이러한 부식현상을 예방하고 맑은 물을 마시기 위해서는 내식성이 우수한 스테인레스강이나 고분자 강력 합성수지로 교체해야 한다고 주장했다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.32 no.10
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• pp.31-35
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• 2003

배수설비시스템에 적용되는 각종 기기들의 특징 및 통기관의 선정 방법을 미국의 ASPE code에 제시되어 있는 내용을 중심으로 소개하고자 한다. 건물 내에서 발생하는 오수 및 배수는 항상 건물 외부로 잘 배출시켜야 한다. 이러한 배수시스템은 원활한 배수가 수행되어야 하도록 수평배수관은 적합한 구배를 주어야 하며, 부지경계선 밖에 설치된 공공하수도와 체결하여 한다. 오수배관은 지상에 노출시키거나 사설정화조를 체류하지 않고 우수로에 직접 배출할 수 없다. 배수설비를 설계할 때의 문제점은, 배수배관 및 통기관을 선정시 선정된 관경이 최적화되었는지 평가하는데 있다. 즉, 현존하는 건축물의 배수시스템에서 문제점이 발생하지 않는다고 설계된 배수배관경 및 통기관경이 최적화된 것으로 평가하기에는 어려움이 있다고 판단된다.(중략)

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.308-311
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• 2010

본 연구에서는 유한요소해석을 통하여 나선 주름모양 소방용 파이프를 모델링하여 각 모델간의 발생응력과 변형량을 상호간에 비교 검토하여 강도 안전성이 우수한 배관시스템의 설계 최적화를 하기 위함이 연구의 목적이다.

• Fire Science and Engineering
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• v.29 no.3
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• pp.21-30
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• 2015

In this study, we try to suggest measures to reduce leakage at a joint between CPVC piping for a sprinkler system and a pipe expansion through reviews of domestic and foreign standards and related tests. The quality of the waterproof rubber packing material between a valve socket and pipe expansion nut was examined. In the leak test, the valve socket material over the expansion part of the metal pipe nut was found to use a metal part or a schlorinated polyvinyl chloride pipe nut part. In addition, the KS B 0221 standard for parallel pipe threads with threaded and thread inspection criteria and inspection standards in order to ensure an acceptable quality of valve socket, there is a need to amend the regulations to comply with the KS B 5223 (screw thread limit gauges parallel pipe threads). We do not have detailed standards for expansion piping nuts for waterproof rubber ring material, so we need to amend the relevant criteria for EPDM material to be used with excellent waterproofing, for which both NBR and EPDM are currently used.

• Journal of the Korean Institute of Gas
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• v.4 no.4 s.12
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• pp.6-12
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• 2000

We have developed a new split tee which can be used to effectively branch into a main gas steel pipelines without losing any gas pressure or having to shut down a line. The split tee has been designed considering the locations of branch connection to the pipelines. Therefore, we could keep the depth of buried pipelines which used to be the problem of the conventional split tees. Test results of the developed split tee showed that the performance of the tightness, hydraulic strength, sealing, welding, bending, and compatibility were excellent. The application of the split tee can provide the advantage of eliminating cost and time, and easy field pipeline coatings.

• Fire Science and Engineering
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• v.29 no.4
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• pp.61-66
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• 2015

PVC pipe has excellent corrosion resistance and chemical resistance and is broadly used. However there are no regulations regarding exposed piping material in buildings. There is growing concern about the vulnerability of piping to fires and generating toxic gas. Exposed piping should be made of incombustible materials to prevent spreading of toxic gas and to minimize damage to life and property in case of fire. Many big structures are being built, and concerns regarding damage by fire are continuously growing. In these circumstances, we should reinforce fire safety standards for buildings and heighten safety consciousness to become a well-developed country. For these reasons, we investigated the materials used for exposed piping and the standards of well-developed countries to enhance safety. We tried to figure out the alternatives by examining the actual conditions of each region's buildings. Based on the use of incombustible materials for exposed piping in each region, we tried to enhance the effectiveness for safety by suggesting revisions for related laws and regulations.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.6
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• pp.483-489
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• 2016

The typical methods used for inspecting ferromagnetic pipes include the ultrasonic testing (UT) contact method and the following non-contact methods: magnetic flux leakage (MFL), electromagnetic acoustic transducers (EMAT), and remote field eddy current testing (RFECT). Among these methods, the RFECT method has the advantage of being able to establish a system smaller than the diameter of a pipe. However, the method has several disadvantages as well, including different sensitivities and difficult-to-repair coil sensors which comprise its array system. Therefore, a giant magneto-resistance (GMR) sensor was applied to address these issues. The GMR sensor is small, easy to replace, and has uniform sensitivity. In this experiment, the GMR sensor was used to measure remote field and defect signal characteristics (in the axial and radial directions) in a ferromagnetic pipe. These characteristics were measured in an effort to investigate standard defects at changing depths within a pipe. The results show that the experiment successfully demonstrated the applicability of the GMR sensor to RFECT signal detection in ferromagnetic pipe.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.355-362
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• 2016

The pipe material is selected according to the physical and chemical properties of the fluid flowing within it. Because the fluid used in fire extinguish systems is water, the various foreign substances dissolved in it cause scale to form on the pipe wall and accelerate the corrosion and aging of the pipe itself. This results in an increase in the friction loss and eventually degrades the efficiency of the pump. The use of CPVC (Chlorinated Poly-Vinyl Chloride) pipes was confirmed to reduce the friction loss compared to conventional steel pipes in the design and construction stages. The friction loss was found to be 76.64MPa with a C-value of 120 for the steel pipe and 50.72 MPa with a C-value of 150 for the CPVC pipe in an actual apartment construction environment. It was confirmed that the friction loss was improved by about 34% when using the CPVC pipe. When the steel and CPVC pipes were employed in the construction, the construction costs were 1,585,158 and 931,842 won, respectively. Therefore, it was shown that the construction cost was reduced by about 41%. We investigated the safety of the fire extinguishing system and the improvement in the economic performance due to the reduction in the total installed capacity by studying practical applications in the field.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.29 no.6
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• pp.43-48
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• 2000

생태 건축학적인 수자원의 이용에 대한 개념을 수자원의 재활용 측면에서의 중수 및 배수열의 이용, 자연자원의 유효이용 측면에서 우수의 이용, 수질환경의 개선과 수자원 이용설비의 내구성 향상 측면에서 배관의 세척에 대한 필요성 및 현황을 중심으로 기술함.