• 한국가스학회지
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• 제21권5호
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• pp.70-76
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• 2017

"도시가스사업법" 및 "액화석유가스의 안전관리 및 사업법" 관련 기준(KGS Code)에서는 가스배관의 이음부(용접이음매 제외)와 전기설비(전기개폐기, 전기계량기, 전기접속기, 전기점멸기 등)와의 이격거리를 규정하고 있다. "전기설비기술기준"에서도 가스관련 법령과 부합되게 전기설비와 가스배관의 이음부와의 이격거리를 규정하고 있다. "도시가스사업법" 관련 기준의 경우 공급시설 기준과 사용시설 기준에서 규정하는 이격거리가 상이하다. 본 연구에서는 LP가스가 배관의 이음부에서 누출되는 경우 점화 가능 거리를 실증 실험하고, 현재 가스 관련 기준에서 규정하고 있는 전기설비와 가스설비와의 이격거리 기준의 적정성에 대해 검토하였다. 실험 결과 배관의 이음부에서 가스가 누출되는 경우 기준에서 규정하고 있는 30cm 이상의 거리에서도 점화가 가능함을 확인하였다. 따라서, 현재 "도시가스사업법" 및 "액화석유가스의 안전관리 및 사업법" 관련 기준에서 규정하고 있는 가스배관과 전기설비와의 이격거리 기준이 적절한 것으로 판단되었다.

• 한국산업융합학회 논문집
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• 제23권5호
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• pp.757-763
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• 2020

City gas buried pipes are managed by corrosion protection to prevent corrosion. In the case of the press-in section, the double pipe and the main pipe may cause corrosion under the influence of stray current, which can shorten the life of the pipes. In addition, if the insulator is filled in the press-in section, the press-in section itself is a single structure, and can be directly affected by external impact, and when the surrounding ground subsidence occurs, the stress may be concentrated, resulting in serious consequences. In this study, a serration-type shock absorber in the form of a sliding support was proposed as a new buried double piping construction method using EPS. The serration-type shock absorber can contribute to the improvement of the integrity of the buried double piping, as it can utilize the gas piping's own ductility and stress distribution characteristics with proper anti-corrosion management and shock-absorbing material properties by preventing contact inside the buried double pipe. However, for application to ground piping, there remains a task to supplement the vulnerability against fire due to the characteristics of EPS materials.

• 산업진흥연구
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• 제2권1호
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• pp.9-13
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• 2017

본 연구는 주택용 가스배관 체크앵글 안전밸브에 관한 것으로 긴급 발생시 1초 이내에 수동으로 차단이 가능하고, 또 손의 힘으로 가압 3kg에 터치가 가능 하도록 하고, 또 긴급시 차단 작동 후 차단 볼 지름이 7mm로 번복 사용이 가능하도록 기술 개발 하였다. 연구결과 첫째 밸브 작동 후. 평균 0.61 초로 나타났다. 따라서 안전밸브로서 사용하여도 작동에는 문제가 없는 것으로 나타났다. 둘째, 손의 힘으로 가압 3kg이내 터치에 모두 작동 되었다. 셋째, 차단 볼 지름이 7mm로 번복 사용한 결과 모두 이상 없는 것으로 나타났다. 본 연구에서 가스배관 체크앵글 안전밸브를 개발하고 기존 밸브와의 시험을 통하여 성능을 검증한 것에 의미가 있다.

• 한국해양공학회지
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• 제15권3호
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• pp.63-68
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• 2001

SG-365 steel is an important material and used for manufacturing a pressure vessel which the gas piping. In this investigation, the elastic plastic fracture toughness of this material is evaluated by the an unloading compliance method according to the ATM E813-97 method on the smooth and side groove 1CT specimens. The effect of smooth and side groove is studied on the elastic plastic fracture toughness. The side grooved specimen is very useful in estimation of the $J_IC. Because it is much easier than the smooth specimen to the onset of the ductile tearing by the R curve method. Besides, it improves the accuracy of toughness values, decreases the scattering of them and tunneling and shear lip by the side groove.

• 동력기계공학회지
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• 제11권1호
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• pp.127-133
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• 2007

SG-365 steel is an important material and used for manufacturing a pressure vessel which the gas piping. In this investigation, the elastic plastic fracture toughness of this material is evaluated by the unloading compliance method according to the ASTM E813-97 and E1152-97 method on the smooth and side groove 1CT specimens. The effect of smooth and side groove is studied on the elastic plastic fracture toughness. The side grooved specimen is very useful in estimation of the $J_{IC}$. It is much easier than the smooth specimen to the onset of the ductile tearing by the R curve method. Besides, it improves the accuracy of toughness values, decreases a phenomenon of the tunneling and shear lip by the side groove.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.350-356
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• 2001

SG-50 steel is an important material and used for manufacturing a pressure vessel which the gas piping. In this investigation, the elastic plastic fracture toughness of this material is evaluated by the an unloading compliance method according to the ASTM E813-97 and E1152-97 method on the smooth and side groove 1CT specimens. The effect of smooth and side groove is studied on the elastic plastic fracture toughness. The side grooved specimen is very useful in estimation of the J$_{IC}$. Because it is much easier than the smooth specimen to the onset of the ductile tearing by the R curve method. Besides, it improves the accuracy of toughness values, decreases the scattering of them and tunneling and shear lip by the side groove.e.

• Tribology and Lubricants
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• 제30권2호
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• pp.124-129
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• 2014

The piping system accounts for a large portion of the machinery structure of a plant, and is considered as a very important mechanical structure for plant safety. Accordingly, it is used in most energy plants in the nuclear, gas, and heavy chemical industries. In particular, the piping system for a nuclear plant is generally complicated and uses the reactor and its cooling system. The piping equipment is exposed to diverse loads such as weight, temperature, pressure, and seismic load from pipes and fluids, and is used to transfer steam, oil, and gas. In ultrasound infrared thermography, which is an active thermography technology, a 15-100 kHz ultrasound wave is applied to the subject, and the resulting heat from the defective parts is measured using a thermography camera. Because this technique can inspect a large area simultaneously and detect defects such as cracks and delamination in real time, it is used to detect defects in the new and renewable energy, car, and aerospace industries, and recently, in piping defect detection. In this study, ultrasound infrared thermography is used to detect information for the diagnosis of nuclear equipment and structures. Test specimens are prepared with piping materials for nuclear plants, and the optimally designed ultrasound horn and ultrasound vibration system is used to determine damages on nuclear plant piping and detect defects. Additionally, the detected images are used to improve the reliability of the surface and internal defect detection for nuclear piping materials, and their field applicability and reliability is verified.

• 한국가스학회지
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• 제18권6호
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• pp.14-20
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• 2014

본 연구에서 배관계의 구조 건전성을 보장할 수 있는 배관 지지대 설계 절차를 ASME 코드에 따라 수행하였다. 본 설계 절차는 단순화된 설계식 및 여러 하중에 대한 보수적인 허용 값을 제공한다. 배관 스트랩 지지대를 구성하는 바닥판, 바닥 지지판 및 앵커 볼트에 대한 응력해석을 수행하여 ASME 코드 상호작용 설계식을 사용하여 구조 건전성을 평가하였다. 여러 하중에 대한 하중 및 하중 조합에 대한 응력 수준이 허용 값 이내에 분포하므로 구조적 건전성을 유지한다고 평가할 수 있다.

• 한국가스학회지
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• 제16권1호
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• pp.22-25
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• 2012

Welding and/or fusion in polyethylene(PE) system made on site is focused on the control of the welding or fusion process to follow proper procedure. The process control is important, but it is not sufficient for the long term reliability of a pipe system. To achieve the rate of failure close to zero, Non Destructive Testing(NDT) is necessary in addition to joining process control. For electrofusion joints several non-destructive testing methods are available. The ultrasonic phased array technique is possible to detect various defects including wire deviations and regions with lack of fusion. In this studies, testing was carried to detect the defect after electrofusion joining of polyethylene piping is utilized by the ultrasonic phased array technique. From testing data, ultrasonic phased array technique is recommended as a reliable non-destructive testing method.

• 한국압력기기공학회 논문집
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• 제4권2호
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• pp.1-6
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• 2008

Very High Temperature Gas Cooled Reactor (VHTR) has been selected as a high energy heat source for nuclear hydrogen generation. The VHTR can produce hydrogen from heat and water by using a thermo-chemical process or from heat, water, and natural gas by steam reformer technology. A co-axial double-tube primary hot gas duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger (IHX) for the VHTR. In this study, a preliminary design analysis for the primary HGD of the nuclear hydrogen system was carried out. These preliminary design activities include a determination of the size, a strength evaluation and an appropriate material selection. The determination of the size was undertaken based on various engineering concepts, such as a constant flow velocity model, a constant flow rate model, a constant hydraulic head model, and finally a heat balanced model.