• 제목/요약/키워드: pipes

검색결과 2,286건 처리시간 0.026초

Study on the Calibration System of Flow Meters in Partly Filled Pipes (비만관 유량계 교정 시스템 구축에 관한 연구)

  • Yoo, Sung-Ho;Lee, Dong-Rak;Lee, Min-Soo
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2005년도 연구개발 발표회 논문집
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    • pp.141-146
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    • 2005
  • Flow meters in partly filled pipes are set up and run in Korea now days, but there are no standard calibration procedures for the flow meters in accordance with ISO/IEC 17025, the standard calibration procedure based on the standard calibration procedures for flow meter in closed conduits and the technical notes of flow meter's makers is developed. the measurement uncertainty of the calibration for the flow meter in partly filled pipes is evaluated.

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Analysis of Behavior Characteristics of Underground Flexible Pipe (II) (지중 연성관의 거동특성 분석 (II))

  • 이대수;상현규;김경열
    • Proceedings of the Korean Geotechical Society Conference
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    • 한국지반공학회 2002년도 봄 학술발표회 논문집
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    • pp.287-294
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    • 2002
  • Underground flexible pipes for electric cables are subject to external loads and surrounding soil pressure. Particularly, strain of flexible pipes is of great concern in terms of safety and maintenance for electric cables. In this study, the actual size tests were carried out to investigate strain-deformation relation for underground flexible pipes subject to vehicle loads with various depths and degree of compaction.

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A Study on Standards for Pressure Relief Valve Vent Pipes from LPG Storage Tanks (LPG용 압력방출밸브 방출관 설치기준 개선방안)

  • Lee, Jin-Han;Eom, Suk-Hwa;Kim, Lae-Hyun
    • Journal of the Korean Institute of Gas
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    • 제16권4호
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    • pp.59-64
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    • 2012
  • The dispersion of gas discharged from the vent pipes of pressure relief valves attached LPG (Liquefied Petroleum Gas) storage tank was studied. In general, vent pipes should be positioned so that they discharge vertically upwards in a safe place, and installed so that, in the event of ignition of discharged gas, flame impingement on any vessel, equipment or piping is avoided[1][2]. In Korea, on the other hand, there are various type of the end of vent pipes because there is no rule for discharge directions from the vent pipes. In this paper, we took 4 types of vent directions from the pipes in to account, such as vertically upward, vertically downward, vertically 4-way and horizontally 2-way direction. A software package, FLACS, was adopted to simulate gas dispersion from the vent pipes. We found that vertically downward, vertically 4-way and horizontally 2-way discharge from vent pipes were undesirable to avoid ignition on near ground. Therefore, it was obvious that vertically upward opening of a vent pipe is the best option to discharge in a safe place.

A Study on the Possibility of using Light-Wall Stainless Steel Pipe for Water-Based Fire Protection System (수계소화설비용 경량벽 스테인리스 강관의 사용가능성 평가에 관한 연구)

  • Nam, Jun-Seok;Won, Sung-Yeun;Kim, Yong-Ho;Min, Kyung-Tak;Park, Seung-Min
    • Fire Science and Engineering
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    • 제24권5호
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    • pp.94-101
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    • 2010
  • The pipes using in water-based fire protection systems are used steel pipes for ordinary piping, carbon steel pipes for pressure service, copper and copper alloy seamless pipes and tubes, etc. By last buildings of high-rising, complexity, in fire protection systems, the corrosion resistance, easy construction, lightweight and cost-effective use of the pipes is being considered. Among the pipes, the possibility of used for fire protection system being used in the existing copper pipe of material properties, strength, corrosion resistance, heat resistance through and compare the performance was evaluated. As a result of that assessment light gauge stainless steel pipes for ordinary piping (KS D 3595) at a water pressure of less than 1.2 MPa can be used in sufficient physical properties, strength, corrosion resistance, heat resistance and have been observed.

A study on the basic experiment of performance criteria for application of pipe bursting method in actual field (Pipe Bursting 공법의 적용성 검토를 위한 주요 성능평가 항목의 기초실험연구)

  • Park, Sangbong;Kim, Kibum;Seo, Jeewon;Park, Sanghyuk;Koo, Jayong
    • Journal of Korean Society of Water and Wastewater
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    • 제32권5호
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    • pp.435-443
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    • 2018
  • Most of aged water supply pipes have been replaced by the open cut method. However, this method has some limitations because water pipes, in many cases, are buried together with other underground facilities or are buried in the middle of high-traffic roads or in narrow alleyways where boring machines cannot be used. This research developed a pipe bursting device for small diameter pipes that enables pipe replacement without excavating the ground, by the busting of existing buried pipes followed by the traction and insertion of new pipes. As a results of examining the field applicability of the developed device, PE pipes and PVC pipes required the tractive force of 413.65~665.69 kgf and 457.43~791.35 kgf respectively, plus an additional 30 % tractive force per elbow. The proper number of bursting head was demonstrated that the connection of more than 2 heads could secure a stable bending radius of 15D. The developed device can be improved through field experiments involving various pipe types and pipe diameters, as well as presence/absence of elbow, so as to be utilized regardless of diverse variables according to the conditions of the soils surrounding existing pipes.

A Study on the Ring Deflection According to Compaction of Buried Polyethylene Pipes (지중매설 폴리에틸렌관의 다짐도에 따른 관변형 연구)

  • Seungcheol Baek;Seungwook Kim;Byounghan Choi;Sunhee Kim
    • Journal of the Korean GEO-environmental Society
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    • 제25권10호
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    • pp.5-10
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    • 2024
  • Flexible pipes have the property of resisting external loads by utilizing the rigidity of the pipe and the surrounding ground, and have recently been in the spotlight because they are lighter in weight and have excellent durability compared to concrete pipes. In this study, the behavior characteristics of buried polyethylene pipe, a representative flexible pipe, were examined. Double-walled and multi-walled polyethylene pipes were used, and the structural behavior of the polyethylene pipe was evaluated based on a 5% deflection of the pipe diameter suggested in the design standards for flexible pipes. For the polyethylene pipe, the material properties of the pipe were identified through a ring stiffness test, and the behavior characteristics in the ground were reviewed through the simulation experiment of the buried polyethylene pipes. In addition, a finite element analysis model was developed based on the results of underground burial simulation experiments, and the behavior characteristics of polyethylene pipes according to backfill conditions were evaluated using the developed finite element analysis model and design equation. As a result of the study, it was confirmed that the capacity of the pipes and the compaction of the backfill are the main factors that determine the structural performance of the buried polyethylene pipe.

Motion Control Algorithm for Crawler Type In-Pipe Robot (크롤러 방식 터널로봇의 모션제어 알고리즘)

  • Bae, Ki-Man;Lee, Sang-Ryong;Lee, Sang-il;Lee, Choon-Young
    • IEMEK Journal of Embedded Systems and Applications
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    • 제3권2호
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    • pp.66-73
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    • 2008
  • The pipes have been laid underground while the industry is developing. We have to take maintenance procedure when the pipes are cracked or ruptured. It is very difficult jop to check pipe's crack because the pipes are narrow and laid underground. Using in-pipe robot, we can check the conditions of inner section of pipes, therefore, we designed a crawler type robot to search cracked pipe. In this paper, we have made a special focus on the control of the robot using differential drive algorithm to move in curved section of pipes. The detailed design of the robot with experimental result show the effectiveness of the robot in pipe maintenance.

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THERMAL ANALYSIS OF SURFACE HEAT PIPE INSTALLED PANEL OF GEOSTATIONARY SATELLITE (외장형 HEAT PIPE 가 장착된 정지궤도 위성 패널의 열해석)

  • Jun H.Y.;Kim J.H.
    • Journal of computational fluids engineering
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    • 제11권3호
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    • pp.8-13
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    • 2006
  • The north panel of a geostationary satellite is used as one of the main radiators, on which communication equipment or bus equipment are installed. The thermal control of panel is designed by using embedded heat pipes and surface heat pipes (or external heat pipes) to spread out heat dissipated from equipment all over the radiator evenly and finally to reject the heat to the space through the radiator efficiently. This panel is also divided by several areas based on the operating temperature and dissipation of equipment in order to increase heat rejection capability of radiator. The thermal analysis is carried out for the hot case, Winter Solsitce EOL (End Of Life), in order to validate thermal design of the panel utilized 6 surface heat pipes and 8 embedded heat pipes. The sensitivity studies for the heat pipe failure case and no heat pipe case are performed and compared to its normal state. The heat transport capability of heat pipe is also obtained from these calculations.

Behavior of Elbows with Ovalization of the Tangential Pipes (직선배관 타원변형을 고려한 엘보우 거동)

  • Lee, Sang-Ho;Song, Hyeon-Seob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제11권12호
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    • pp.5177-5183
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    • 2010
  • The effects of the ovalization of the tangential pipes to the elbows are analyzed. The geometric nonlinear behaviors of the elbows are shown with the element capable of ovalization. The relationships between the length of the tangential pipes in the models and the bend angles of the elbows are analyzed to supplement the ASME code. And the proper length of the tangential pipes for the elbow models are suggested.

A Case Study of Flexible Sewer Pipes Behaviors - Compaction Ratio·Inner Deflection Ratiov·Ring Stiffness - (현장중심형 하수도용 연성관의 거동특성에 대한 고찰 - 다짐도·변형률·강성 간의 관계정립 -)

  • Kim, Young-Jin
    • Journal of the Korean Society for Advanced Composite Structures
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    • 제4권2호
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    • pp.31-38
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    • 2013
  • As the Sewer Pipe is transformed by the expansion of life cycle as a result of the technology development, flexible pipe is developed by the transformed environmental conditions. To change pipe design, three phases(compaction ration - inner deflection ratio - ring stiffness) should be considered in design conditions. The input data of pipe design were provided by compaction-inner deflection ratio-ring stiffness. M oreover, The guidelines of sewerage pipes should be considered by flexible pipes design criteria.