A fire sprinkler system is very important to extinguish fire in the building. The sprinkler system initiates sprinkler discharge if the detection system identifies a developing fire and opens the pre-action valve. However, pre-action fire sprinkler systems mainly installed in the underground parking lot at the apartment complex do not properly operate at fire if the connection type of fire sprinkler systems does not properly installed and operated. This study identified the relationship between fire dispersion & damage and the connection type of water supply in the sprinkler system from many fire cases at the apartment complex in South Korea. In addition, this study also identified the water supply differences and characteristics between South Korea and foreign countries. The main purpose of this study is also to improve the water connection types in the sprinkler system that can reduce the potential failures of pre-action valve operation through electrical signal system. The study also suggests the improvement plan for water connection types in pre-action fire sprinkler system that can minimize potential failure of pre-action fire sprinkler system. The suggestions for revising the fire safe standard in South Korea includes letting the water supply pipe of sprinkler system water inlet connect to the second side of pre-action valve and the water flow device that can minimize potential failure of sprinkler system.

This study performed a finite element stress analysis of pipe system connected by bellows based on APDL(ANSYS Parametric Design Language) customizing. The effects of different shapes of developed pipes for various parameters are studied using the finite element commercial package for this study. The structural behavior of complex pipe structures with bellows was also investigated to study the interactions between bellows and other parts. Based on the ANSYS APDL, the effect of initial axial and lateral displacements, and internal temperature and pressure on the Von Mises stress distribution is also analyzed.

The industrialization and urbanization forced to increase the density of pipelines such as water supply, sewers, and gas pipelines. The materials used for the existing pipe lines are mostly composed of concretes and steels, but it is true that the development for more durable and efficient materials has been continued performed to produce long lasting pipe lines. Recently, underground pipes serve in diverse applications such as sewer lines, drain lines, water mains, gas lines, telephone and electrical conduits, culverts, oil lines, etc. In this paper, we present the result of investigation pertaining to the structural behavior of unplasticized polyvinyl chloride (PVC-U) flexible pipes buried underground. In the investigation of structural behavior such as a ring deflection, pipe stiffness, 4-point bending test, experimental and analytical studies are conducted. In addition, pipe stiffness is determined by the parallel plate loading tests and the finite element analysis. The difference between test and analysis is about 8% although there are significant variations in the mechanical properties of the pipe material. In addition, it was found by the 4-point bending test there is no problem in the connection between the pipes by coupler.

본 연구는 파이프 줄기초의 보강 방안을 제시하고 영농활용을 목적으로 내재형 온실설계도에 제시되 어 있는 강판조리개 및 U-클램프를 포함하여 온실 파이프들의 결속형태로 많이 사용되고 있는 강선조 리개로 결속한 파이프 줄기초의 인발저항력을 현상시험을 통하여 구명하였다. 그 결과, 강선조리개, 강 판조리개 및 U-클램프의 극한인발저항력의 평균값은 각각 186N, 1601N 및 3303N으로서 결속형태별로 상당히 큰 차이를 보였다. U-글램의 경우가 가장 크고, 강성조리개가 가장 작은 것으로 나타났다. 강 선조리개의 경우는 내재해형 설계기준 1390N보다 아주 작게 나타났다. 그리고 U-클램프의 경우는 기 준 값보다 약 2.3배 정도 크게 나타났으며, 강선조리개보다는 2.0배 정도 크게 나타났다. 실제적으로 단동온실의 경우, 강풍에 의해 인발되어 전파 또는 반파되기도 하지만, 설하중에 의해 침하되는 경우도 예상할 수 있다. 이러한 경우, 줄기초의 하중 지지강도는 줄기초의 결속강도에 따라 다르기 때문에 결 국 줄기초의 침하저항은 인발저항력과 유사할 것으로 판단되었다. 그리고 강판조리개 및 U-클램프의 극한인발저항력, 결속재료의 재료비, 온실의 내구연수 및 재현기간 등만을 고려하여 경제성을 대략적으 로 검토한 결과, 편익(이익) 비용은 약 13,176,000원 정도일 것으로 추정되었다.

This paper presents on the structural behavior of the the methyl methacrylate monomer (MMA) double wide flanged the glass fiber-reinforced polymer(GFRP) pipe composite structures for the manhole raise. The evaluation of structural performance on this composite structure was conducted by the axial load, fatigue load, and ultimate load test. The assessment indicates that the MMA double wide flanged GFRP pipe composite structures was confirmed safety, durability and reliability in result as expected. It was found that this composite structure was able to short working times to around 30-50% and construction costs to around 10-23% with compare other construction methods. Also, environmental pollution and civil complaints will be prevented because there will be no longer any noises, vibrations, dust, or construction wastes.

GRP pipe (Glass-fiber Reinforced Plastic Pipe) lines making use of FRP (Fiber Reinforced Plastic) are generally thinner, lighter, and stronger than the existing concrete or steel pipe lines, and it is excellent in stiffness/strength per unit weight. In this study, we present the result of field test for buried GRP pipes with large diameter(2,400mm). The vertical and horizontal ring deflections are measured for 387 days. The short-term deflection measured by the field test is compared with the result predicted by the Iowa formula. In addition, the long-term ring deflection is predicted by using the procedure suggested in ASTM D 5365(ANNEX) in the range of 40 to 60 years of service life of the pipe based on the experimental results. From the study, it was found that the long-term vertical and horizontal ring deflection up to 60 years is less than the 5% ring deflection limitation.

본 연구에서는 강풍 피해의 절감을 위하여 서까래 파이프 및 파이프 줄기초의 설계 자료를 제공할 목적으로 온실의 지반고정을 위해 일반농가에서 주로 사용되고 있는 서까래 파이프와 내재해형 규격의 단동온실에 주로 사용되는 파이프 줄기초를 대상으로 토성, 다짐도 및 매입깊이에 따른 인발저항력을 실험적으로 검토하였다. 극한인발저항력은 가장 단단한 지반조건인 다짐률 85%, 최대매입깊이 50cm를 기준으로 파이프의 경우는 간척지 흙(실트질 롬) 72.8kgf, 농경지 흙(사질 롬) 60.7kgf, 줄 기초의 경우는 간척지 흙 452.7kgf, 농경지 흙 450.3kgf 으로 줄기초의 경우 파이프 보다 약 6배 이상 인발저항력이 크게 개선되는 것으로 나타났다. 본 연구에서 고려한 토성은 모래함량 35%~59%, 실트함량 39%~58%으로 극한인발저항력이 토성에 따라서 큰 차이가 없는 것으로 나타났으며, 이러한 결과는 온실의 파이프(서까래) 및 줄 기초를 설치할 때 적절한 다짐조건을 유지한다면 토성의 영향을 크게 받지 않고 온실의 지반고정에 대한 안정성 확보에 크게 유리하다는 것을 나타낸다. 본 연구의 결과를 기준으로 줄기초는 다짐률 75% 이상, 일반 파이프의 경우에는 다짐률 85%이상으로 유지하는 것이 온실의 안정성 확보에 유리할 것으로 판단되었다. 특히 내재해형 규격인 줄기초를 적용한다면 기상재해에 따른 온실의 안정성 확보에 크게 유리할 것으로 판단되었다.

The performance of helical hydro turbine in water pipe line depends on the sectional shape of turbine blade, pitch angle of turbine blade, solidity and number of turbine blades, To investigate the effects of these design factors on the performance of helical hydro turbine, flow analysis was carried out by using commercial code ANSYS CFX version 14..5. From CFD analysis we obtained the optimum design factors which were the asymmetric blade shape of NACA4420, the pitch angle of 15 degrees and the solidity of 0.3. These results can be used for the actual design of sphere-shaped helical turbine in water pipe line.

To overcome disadvantages of usual spread foundation in large space structure, some prototypes of a joint of the PHC pile to steel pipe column that directly connects a column to a PHC pile are analytically studied. With the consideration of strength requirement and stress concentration of joint of the PHC pile to column, we suggest the most appropriate one.

In this study, structural stability of large diameter high density polyethylene (HDPE) pipe during installation was numerically investigated in order to investigate the effect of concrete collar dimension, water depth and tension (pulling force). From the numerical simulation results, the total stress of HDPE pipe with designed concrete collar was within 2.5%, so the total weight of concrete collar for sinking of HDPE is important rather than concrete collar dimension. Furthermore, the tension area for possible installation is decreased as the air filling rate is increased. Therefore, it is important to calculate the reasonable tension range before actual installation for safe installation of HDPE pipe.

The common octopus, which has a high growth rate and high market price, is a prime candidate for commercial marine aquaculture operations. We evaluated the effectiveness of two types of shelters (pipe and tire types) for juvenile common octopus growing out in flow-through seawater tanks. Growth rates were evaluated in two experiments. The first experiment (Experiment 1) ran for 72 days, and the second (Experiment 2; replicated) ran for 46 days. Each trial included 40 octopuses fed a diet of frozen sardine (Sardinops melanostictus) and swimming crab (Portunustri tuberculatus) at 3–8% of body weight once every 3 days. In the two experiments, the respective specific growth rates were 0.3 and 0.04%/day in pipe-type shelters and 0.00 and 0.88%/day in tire-type shelters, while the respective percentage survivals were 80 and 80% in pipe-type shelters and 70 and 90% in tire-type shelters. Shelter type had little influence on the growth rate (P < 0.05).

This study was carried out to analyze water suspension in the water supply system through fault tree analysis. And quantitative factors was evaluated to minimize water suspension. Consequently the aim of this study is to build optimal planning by analyzing scenarios for water suspension.Accordingly the fault tree model makes it possible to estimate risks for water suspension, current risks is 92.23 m3/day. The result of scenario analysis by pipe replacement, risks for water suspension was reduced 7.02 m3/day when replacing WD4 pipe. As a result of scenario analysis by water district connections, the amount of risk reduction is maximized when it is connecting to network pipe of D Zone. Therefore, connecting to network pipe for D Zone would be optimal to reduce risk for water suspension.

본 연구에서는 테이퍼 보에 대한 미분방정식의 일반해에 캔틸레버 보의 경계조건을 적용하여 모드특성을 추정한다. 또한, 휨을 받는 테이퍼 원형강관 캔틸레버 보에 발생하는 관통균열을 모델링하기 위하여 에너지 방법을 이용하여 균열보에 대한보 길이방향 휨강성을 구한 후 이를 이용하여 테이퍼 원형강관 캔틸레버 균열보에 대한 고유주파수와 모드형상을 추정한다. 보 길이에 따른 균열보의 휨강성 변화는 기존 연구에서 밝혀진 현상과 유사하게 합리적인 양상을 보였으며, 유도한 휨강성을 적용하여 산정한 균열보의 고유주파수는 균열 크기가 증가할수록 감소함을 확인하였고, 모드형상은 균열발생에 의해 변화함을 알 수 있었다. 연구결과는 향후 테이퍼 원형강관 캔틸레버 보 형태의 타워 구조물에 대한 진동기반 균열탐지에 활용될 수 있을 것으로 판단된다.

Recently, sewer–pipe constructions replacing deteriorated pipes are currently underway in the downtown area. To resolve many problems in the conventional method of open-cut construction, lining-board system using light-weight GFRP panels is developed. The pultruded GFRP panels can be successfully used for the developed lining-board system as temporary decks and retaining walls in virtue of light weight, high strength and high durability. In this paper, the structural safety and serviceability of the lining-board system are examined through FE analyses and experiments. Further more, a field application of the lining-board system is presented. The field application shows that quality and environment of construction can be significantly improved.

Fuel pump of a vehicle is a device to supply the fuel from fuel tank to engine. This study analyzed the pulsatility on the shape of fuel supply pipe using a CFD(Computational Fluid Dynamics). Numerical analysis was performed to use 3-dimensional incompressible k-ε turbulent model with measured pressure values at an exit by an experiment. Simulation models used commercial and improved model. In this study, the characteristics of the pulsatility reduced in improved model compared to those in commercial model. The pressure loss, which occurs at the flexure, was effective to pulsatile reduction. Commercial and improved model differed by numbers of flexure. The number of flexure between inlet and outlet decreased the difference of velocity and pressure. Therefore, the design of fuel supply pipe should be considered numbers and shape of flexure.

Recently, the use of buried flexible pipes is widespread and ever increasing trend in the construction field. In this paper, we present the result of an investigation pertaining to the pipe stiffness of buried unplasticized polyvinyl chloride (PVC-U) pipes. To estimate the mechanical properties of PVC pipe produced by the domestic manufacturers, tensile test specimens were prepared and tested. In addition, parallel plate loading tests for the pipes with 150mm and 400mm inside diameters were conducted. From the test result, the pipe stiffness according to the ASTM D 2412 (2008) is estimated.

Glass fiber reinforced thermosetting polymer plastic (GRP) is widely used in the construction industries due to the advantages of their superior mechanical and physical characteristics. Most of pipes are installed for long-term purposes and they should be safely installed in consideration of installation conditions because there are unexpected various terrestrial loading conditions. In this paper, we present the result of investigation for 253 days pertaining to the structural behavior of flexible pipes buried underground. From the buried test results, we predicted long-term, up to 60 years, ring deflection of GRP pipes buried underground based on the method suggested by the existing literature. It was found that the GRP flexible pipe is appropriate because 5% ring deflection limitation of 60 years could be satisfied.

This study is for a pipe cutting apparatus for use in a process of a pipe. The system refers to a novel structure comprised of a main bed, a feeder part and a cutter part. The feeder part is comprised of an AC servo motor unit, a feeding gear unit, a LM guide and a rail. The cutter part is comprised of a blade unit consisting of a blade for cutting, a AC servo motor to rotate the blade unit and a clamp unit to fix the pipe. This study proposes a mechanism of a product by designing the system and analyzes the cutting power. This study will be used as basic data for the design by analyzing the vibration and the structure