• Title/Summary/Keyword: Piping Material

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Leakage-reduction Measures at a Joint between CPVC Piping for a Sprinkler System and a Pipe Expansion (스프링클러설비용 CPVC관과 신축배관 접속부분에서의 누수저감 대책에 관한 연구)

  • Lim, Chun-Ki;Lim, Yun-Tack;Baek, Eun-Sun
    • 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.

Fracture Resistance Characteristics of SA516-Gr.70 Steel Plate for RCS Piping Elbow and Support Skirt (원자로 냉각재배관 엘보우 및 서포트 스컷트용)

  • Son, Jong-Dong;Lim, Man-Bae
    • Journal of the Korean Society of Safety
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    • v.21 no.4 s.76
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    • pp.49-54
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    • 2006
  • The evaluation of elastic-plastic fracture characteristic was investigated in ferrite steel SA 516- Gr70 used for reactor coolant piping elbow and support skirt of pressure vessels. This paper describes the effect of temperature on J-R curve characteristic of this material. The elastic-plastic fracture mechanics parameter J is obtained with unloading compliance method. The test method were analyzed according to ASTM E 813-89 and E 1152-89. Unloading compliance $J_{IC}$ tests were performed on 1 CT specimens at varied temperatures from $25^{\circ}C$ to about $400^{\circ}C$ using a high temperature extensometer. At all temperature, valid $J_{IC}$ measurements could be made and $J_{IC}$ decreased with increasing temperature. SEM fractography schematically illustrates microvoid initiation, growth and coalescence at the tip of a preexisting crack.

Notice of LQ Piping Design for ICHTHYS (ICHTHYS CPF(Central Processing Facility) LQ Piping Design 특이사항(유의사항))

  • Lee, Jaeyoung;Seong, Hyeontaek
    • Special Issue of the Society of Naval Architects of Korea
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    • 2017.10a
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    • pp.46-53
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    • 2017
  • We work for big offshore project in the Korean shipyards as a EPC contract. There are a lot of risks even though the FEED Engineering was taken in the famous engineering company. In case of ICHTHYS CPF, it worked on the FEED activity for several years. Here is mention that design modification was carried how to modify material and specification according to shipyards human resource and yard practice for your reference. Furthermore, I expect that this paper is used for Korean engineer for their reference.

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Evaluation of Fracture Resistance Characteristics of SA 508 CL.1a Carbon Steel for Piping System (SA508 CL.1a 탄소강 배관소재의 파괴저항특성 평가)

  • Seok, Chang-Sung;Kang, Byoung-Gu
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.7 s.166
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    • pp.1147-1154
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    • 1999
  • The objective of this paper is to evaluate the fracture resistance characteristics of SA508 CL.1a carbon steel, and their associated welds manufactured for primary coolant piping system of nuclear power plants. The effect of various parameters such as pipe size, welding method and chemical composition on the material properties were discussed. Test results showed that the offset of pipe size on tincture toughness was negligible, while the effect of welding method on fracture toughness was significant. In addition, Fracture toughness for carbon steel was influenced by silicon contents due to the different steel refining processes.

A study on the optimal design for heat insulation of hot water piping systems using a dynamic programming (동적계획법을 이용한 고온수배관의 최적보온설계에 관한 연구)

  • 유희한;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • v.11 no.1
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    • pp.39-52
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    • 1987
  • Recently, the design problem of heat insulation have been reappraised in the aspect of energy saving due to the rising trend of energy cost. For example, that design problem is increasingly requsted in the fields of accommodation air conditioning systems, hot water supply systems, cargo handling systems, district heating or cooling systems. The rational design of heat insulation of piping systems can not only improve the overall efficiency of energy transfer but also give energy saving. In this paper, the heat insulation problem of district heating systems is therefore modeled as the multi-stage decision processes, suitable for dynamic programming technique. And take the object function as the sum of heat insulation material cost involved construction cost and heat loss cost, and propose the design method to minimize the object function for overall piping systems by dynamic programing. Effectiveness of design method presented here is proved by a computer simulation.

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Evaluation of Thermal Embrittlement for Cast Austenitic Stainless Steel Piping in PWR Nuclear Power Plants (PWR 원전 주조 스테인리스강 배관의 열취화 평가)

  • Kim, Cheol;Jin, Tae-Eun
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.96-101
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    • 2004
  • Cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing and valve bodies in light water reactors. These components are subject to thermal embrittlement at the reactor operating temperature. The objective of this study is to summarize the method of estimating ferrite content, Charpy impact energy and J-R curve and to evaluate the thermal embrittlement of the cast austenitic stainless steel piping used in the domestic nuclear power plants. The result of evaluation, two domestic nuclear power plants used CF-8M and CF-8A material has adequate fracture toughness after saturation.

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A Study on the Safety Evaluation of Design for Piping Materials(III) (배관용 재료의 설계시 안전성 평가에 관한 연구(III))

  • 김복기
    • Journal of the Korean Society of Safety
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    • v.11 no.1
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    • pp.11-15
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    • 1996
  • For the assessment of fracture behaviors of structural components, various fracture mechanics parameters have been applied to date. New approaches to analyze structural fracture performance under elastic-plastic condition have been proposed by the development of testing methods for characterization of material behavior which is defying to the analysis by conventional fracture parameters. In this study, on the assumption that, initiation of crack propagation of a piping materials occurs when the crack tip strain field reaches "the local fracture strain", following two major issues are discussed ; 1) The relationship between the critical value of J-integral($J_{IC}$) and the local fracture strain (${\varepsilon}_c$) in uniaxial tensile test in the region of maximum reduction area was described. 2) To proved the validity of above relations a series of tests were performed under various temperature and on the different piping materials.materials.

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Preliminary Analysis of a Sampling and Transportation System for Leak Detection during Steam Leak Accident of a Pipe in Nuclear Power Plants (원전 내 배관의 증기 누설 사고 시 누설 탐지 포집/이송 시스템 예비 해석)

  • Choi, Dae Kyung;Choi, Choengryul;Kwon, Tae-Soon;Euh, Dong-Jin
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.16 no.2
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    • pp.25-34
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    • 2020
  • As leakage in nuclear power plants could cause a variety of problems, it is very critical to monitor leakage from the safety point of view. Accordingly, a new type of leak detection system is currently being developed and flow characteristics of the sampling and transportation system are investigated by using numerical analysis as a part of the development process in this study. The results showed that the steam mass fraction varied according to the effect of the gap between the insulation and piping component, transportation velocity, and material properties of porous media during the sampling and transportation process. The results of this study should be useful for understanding flow characteristics of the sampling and transportation system and its design and application.

River Embankment Integrity Evaluation using Numerical Analysis (수치해석을 이용한 하천제방의 건전도 평가)

  • Byun, Yo-Seph;Jung, Hyuk-Sang;Kim, Jin-Man;Choi, Bong-Hyuck;Kim, Kyung-Min;Chun, Byung-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.524-528
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    • 2009
  • An influence factors for soundness evaluation of river levee include resistibility and embankment for piping of ground consisting embankment in case piping, permeability coefficient of ground, height of embankment, the width of crest, material characteristics of embankment and foundation ground, shape of embankment slope, an influence for penetration of rainfall or river water in case slope stability. In this study, it was operated a feasibility investigation of existing design result, stability evaluation for permeability coefficient use and permeability coefficient change of foundation ground to investigate an influence in line with permeability coefficient change for result of river levee penetration analysis. The evaluation results of influence factors, the permeability coefficient used in design and it was evaluated influence in safety factor of piping. After the evaluation of influence factors, the permeability coefficient used in the design appears with the fact that differs in a design report about same soil, Accordingly, the stability investigation of embankment by application of literature data can affect stability evaluation results by change factors like a permeability coefficient, void ratio. It should be certainly used material properties by a test in soundness evaluation of river levee.

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UT Inspection Technique of Cast Stainless Steel Piping Welds Using Low Frequency TRL UT Probe (저주파수 TRL 탐촉자를 이용한 Cast Stainless Steel 배관 용접부 초음파탐상기법)

  • Shin, Keon-Cheol;Chang, Hee-Jun;Jeong, Young-Cheol;Noh, Ik-Jun;Lee, Dong-Jin
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.6 no.1
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    • pp.29-36
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    • 2010
  • Ultrasonic inspection of heavy walled cast austenitic stainless steel(CASS)welds is very difficult due to complex and coarse grained structure of CASS material. The large size of anisotropic grain strongly affects the propagation of ultrasound by severe attenuation, change in velocity, and scattering of ultrasonic energy. therefore, the signal patterns originated from flaws can be difficult to distinguish from scattered signals. To improve detection and sizing capability of ID connected defect for heavy walled CASS piping welds, the low frequency segmented TRL Pulse Echo and Phased Array probe has been developed. The experimental studies have been performed using CASS pipe mock-up block containing artificial reflectors(ID connected EDM notch). The automatic pulse echo and phase array technique is applied the detection and the length sizing of the ID connected artificial reflectors and the results for detection and sizing has been compared respectively. The goal of this study is to assess a newly developed ultrasonic probe to improve the detection ability and the sizing of the crack in coarse-grained CASS components.

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