| Project/Area Number |
17K06134
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Design engineering/Machine functional elements/Tribology
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| Research Institution | Numazu National College of Technology |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Keywords | ガスケット / フランジ締結体 / 漏えい / 複合荷重 / 高温 / 漏えい防止 |
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| Outline of Final Research Achievements |
Firstly, the loading conditions that cause large leakage from gasketed flange connections when subjected to combined loads of axial load and bending moment are examined experimentally. The experimental equation that represents the sealing limits is proposed. Secondly, the minimum gasket stress to maintain the tightness of bolted flange connections under the combined loads is analyzed using the finite element method.
Summarizing the experimental and analytical results, it is found that large leakage occurs when the gasket stress at the outer circumference becomes lower than the critical gasket stress. If sufficiently high initial bolt tightening forces are given to obtain high tightness of the flanged connections, the flanged connections is resilient under combined loads that causes yield in the pipes used in the flanged connections.
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| Academic Significance and Societal Importance of the Research Achievements |
化学プラントなど配管系のガスケット付きフランジ締結体は、温度変化による配管の熱膨張・収縮による配管軸方向の荷重に加えて、自重や地震などによる曲げ荷重も考慮する必要がある。本研究により、フランジ締結体の組立て時に初期の密封性能が得られる十分高いボルト締付け力を与えれば、その後配管に塑性変形が生じるような大きな複合荷重が作用しても、大規模な漏えいが発生する可能性は低いことが明らかになった。このことは、現状使用されているフランジ締結体の安全性を裏付けする結果であり、実用上の観点から意義は大きいといえる。
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