基于螺栓力的法兰接头泄漏率预测模型研究
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摘要
螺栓法兰接头在石化装置中应用广泛,也是频繁泄漏部位之一,主要是由于螺栓力不足导致密封垫片应力下降从而引起泄漏,因此接头运行过程中螺栓力变化对于其密封性能至关重要。针对该问题,提出以泄漏率为指标,研究法兰接头螺栓力与垫片应力的关系,构建基于螺栓力的法兰接头泄漏率模型,并开展接头螺栓力和泄漏率试验,验证模型可靠性。实验结果表明,随着内压升高,螺栓力增大、垫片应力下降,螺栓力和垫片应力存在单调对应关系,垫片应力理论计算值与试验值之间对应较好,接头泄漏率理论值同实验值相比具有较好的可比性。因此,基于接头螺栓力预测泄漏率是可行的,同时该模型对于监测法兰接头服役过程中螺栓力的变化具有重要的理论意义。
Bolted flange joints are widely used in the petrochemical plants, and it is one of the weak locations for the occurrence of leakage. This is mainly because of the bolt force reduction. Thus bolt force is very important for the joints kept in sealing in service. Indexed with the leakage rate parameter, the relationship between the bolt force and gasket stress has been studied. The leakage rate model was established on the basis of bolt force. Corresponding experiments have been performed to verify this model. It was shown that with internal pressure increasing, the bolt force increases and gasket stress reduces, and there exists a monotonic relationship between the bolt force and gasket stress. The theoretical gasket stress value corresponds well with the experimental value. The calculated leakage rates for the joints also have a well agreement with the experimental value. Therefore, it is feasible to predict the leakage rate for the bolted flange joints by bolt force, and also this model is quite meaningful in monitoring the bolt force in the service of flange joint.
Bolted flange joints are widely used in the petrochemical plants, and it is one of the weak locations for the occurrence of leakage. This is mainly because of the bolt force reduction. Thus bolt force is very important for the joints kept in sealing in service. Indexed with the leakage rate parameter, the relationship between the bolt force and gasket stress has been studied. The leakage rate model was established on the basis of bolt force. Corresponding experiments have been performed to verify this model. It was shown that with internal pressure increasing, the bolt force increases and gasket stress reduces, and there exists a monotonic relationship between the bolt force and gasket stress. The theoretical gasket stress value corresponds well with the experimental value. The calculated leakage rates for the joints also have a well agreement with the experimental value. Therefore, it is feasible to predict the leakage rate for the bolted flange joints by bolt force, and also this model is quite meaningful in monitoring the bolt force in the service of flange joint.
引文
[1]张柱,纪士铎,吴晓雷.法兰连接系统中密封垫片的失效分析及选用[J].中国石油和化工标准与质量,2013,33(23):62-62.
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[5]蔡仁良,蔡暖姝,尤子涵,等.螺栓法兰接头安全密封技术(一)——安装螺栓载荷[J].化工设备与管道,2012,49(3):12-17.
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[7]Horiuchi K,Takagi Y,Sawa T.FEM Stress Analysis and the Sealing Performance Evaluation of Pipe Flange Connections Subjected to External Bending Moments and Internal Pressure[C]//ASME 2011 Pressure Vessels and Piping Conference.2011:486-495.
[8]Hiratsuka M,Kobayashi T,Nishiura K,et al.Behavior of Bolt Force Changes of Flanged Connections Under Thermal Loading[C]//ASME 2013 Pressure Vessels and Piping Conference.2013:V002T02A027.
[9]Kobayashi T.Study on the Deflection of Gaskets and its Effects on Residual Bolt Forces and Tightness of Bolted Flanged Connections[C]//ASME 2014 Pressure Vessels and Piping Conference.American Society of Mechanical Engineers,2014:V002T02A017-V002T02A017.
[10]刘麟,黄星路,顾伯勤.基于非线性垫片径向应力分布的螺栓法兰连接泄漏率预测方法[J].润滑与密封,2010,35(7):9-13.
[11]顾伯勤.多孔介质气体流动模型在垫片密封中的应用[J].南京化工大学学报,1999(1):19-23.
[12]张增禧,王曙,顾伯勤,等.垫片高温性能及其表示方法[J].化工设备与管道,2001,38(4):63-64.
[13]GB/T 12385—2008,管法兰用垫片密封性能试验方法[S].
[2]刘洁,王强.阀用柔性石墨金属波齿复合垫片密封失效分析及改进[J].流体机械,2013,41(3):46-48.
[3]朱磊.螺栓法兰连接的失效案例分析及有关进展的讨论[J].压力容器,2012,29(2):42-48.
[4]蔡仁良.流体密封技术[M].北京:化学工业出版社,2013:495-504.
[5]蔡仁良,蔡暖姝,尤子涵,等.螺栓法兰接头安全密封技术(一)——安装螺栓载荷[J].化工设备与管道,2012,49(3):12-17.
[6]蔡暖姝,应道宴,蔡仁良,等.螺栓法兰接头安全密封技术(四)——垫片应力[J].化工设备与管道,2013,50(3):6-15.
[7]Horiuchi K,Takagi Y,Sawa T.FEM Stress Analysis and the Sealing Performance Evaluation of Pipe Flange Connections Subjected to External Bending Moments and Internal Pressure[C]//ASME 2011 Pressure Vessels and Piping Conference.2011:486-495.
[8]Hiratsuka M,Kobayashi T,Nishiura K,et al.Behavior of Bolt Force Changes of Flanged Connections Under Thermal Loading[C]//ASME 2013 Pressure Vessels and Piping Conference.2013:V002T02A027.
[9]Kobayashi T.Study on the Deflection of Gaskets and its Effects on Residual Bolt Forces and Tightness of Bolted Flanged Connections[C]//ASME 2014 Pressure Vessels and Piping Conference.American Society of Mechanical Engineers,2014:V002T02A017-V002T02A017.
[10]刘麟,黄星路,顾伯勤.基于非线性垫片径向应力分布的螺栓法兰连接泄漏率预测方法[J].润滑与密封,2010,35(7):9-13.
[11]顾伯勤.多孔介质气体流动模型在垫片密封中的应用[J].南京化工大学学报,1999(1):19-23.
[12]张增禧,王曙,顾伯勤,等.垫片高温性能及其表示方法[J].化工设备与管道,2001,38(4):63-64.
[13]GB/T 12385—2008,管法兰用垫片密封性能试验方法[S].