A Three-Factor Accelerated Aging Test Platform of Thermal, Mechanical Compression, Pressured SF6, and a Leakage Test System for GIS O-Ring Seals

The multifactor accelerated aging test is an important means to predict the lifetime of gas-insulated switchgear (GIS) O-ring seals, while the leakage rate (LR) is a potential index for failure evaluation. This article proposed a three-factor accelerated aging test platform and a leakage test system (LTS) for GIS seal rings. The aging factors are thermal, mechanical compression, and pressured SF6 gas. The pressure aging vessel (PAV) can be filled with various gases to simulate the operating conditions of the GIS and age multiple samples simultaneously. During the aging process, leakage tests are conducted on flange pairs without disassembling and separating the seal rings. After the test, the aging can be continued so as to study the evolution of LR with aging time. In order to analyze the properties of leakage test and validate the platform, a three-factor accelerated aging and a traditional two-factor accelerated aging (thermal and compression) were conducted on GIS O-ring seals of EPDM material. Compression set (CS) and LR were tested. The result showed that a steady inherent LR $F_{0}$ exists for the LTS. The LR rose linearly with accumulating time, allowing simplified calculation of LR. The three-factor aged samples had significantly smaller CS than those of the two-factor aged samples, indicating that the working condition of GIS with SF6 atmosphere significantly slows the aging rate of GIS seal rings. The findings proved that the three-factor accelerated aging test platform and LTS effectively simulate the operating conditions of GIS seal rings and evaluate their properties.

[1]  Michael R. Keenan,et al.  Methods for Predicting More Confident Lifetimes of Seals in Air Environments , 2000 .

[2]  M. Jaunich,et al.  Effects of heterogeneous aging in compressed HNBR and EPDM O-ring seals , 2016 .

[3]  Mathias Christopher Celina,et al.  Density measurements as a condition monitoring approach for following the aging of nuclear power plant cable materials , 1999 .

[4]  J. Bolland.  Kinetic studies in the chemistry of rubber and related materials. I. The thermal oxidation of ethyl linoleate , 1946, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[5]  Liang Zhang,et al.  A Novel PD Detection Technique for Use in GIS Based on a Combination of UHF and Optical Sensors , 2019, IEEE Transactions on Instrumentation and Measurement.

[6]  Jin Gao,et al.  Aging of ethylene–propylene–diene monomer (EPDM) in artificial weathering environment , 2007 .

[7]  Zhongmin Geng,et al.  Research on aging and working life of material for GIS sealing O-rings , 2017 .

[8]  Wang Wen-chang.  Comparison and Analysis of Physical Properties among EPDM,NBR and CR O-Rings Used in Gas Insulating Switch , 2008 .

[9]  K. Gillen,et al.  Rigorous experimental confirmation of a theoretical model for diffusion-limited oxidation , 1992 .

[10]  Rui Yang,et al.  The effect of thermo-oxidation on the continuous stress relaxation behavior of nitrile rubber , 2015 .

[11]  X. Yao,et al.  Graphene rubber composites integrated sealing rings for monitoring contact pressure and the aging process , 2019, Composites Part A: Applied Science and Manufacturing.

[12]  E. Turi,et al.  The deterioration of polypropylene by oxidative degradation , 1965 .

[13]  L. Paul Steele,et al.  Sulfur hexafluoride—A powerful new atmospheric tracer , 1996 .

[14]  N. J. Dhooge,et al.  Density profiling of polymers , 1986 .

[15]  M. Jaunich,et al.  Temperature-dependent leak tightness of elastomer seals after partial and rapid release of compression , 2015 .

[16]  Gaoliang Peng,et al.  Computer vision algorithm for measurement and inspection of O-rings , 2016 .

[17]  K. Gillen,et al.  Quantitative model for the time development of diffusion-limited oxidation profiles , 1997 .

[18]  Xinglu Huang,et al.  Investigation of leak detection method by means of measuring the pressure increment in vacuum , 2006 .

[19]  M. Bergoglio,et al.  Leak rate metrology for the society and industry , 2012 .

[20]  M. Jaunich,et al.  Analysis of O-Ring Seal Failure under Static Conditions and Determination of End-of-Lifetime Criterion , 2019, Polymers.

[21]  Nihar S. Raj.  Gas Insulated Substations , 2013 .

[22]  Robert Bernstein,et al.  Lifetime predictions of EPR materials using the Wear-out approach , 2006 .

[23]  Robert Bernstein,et al.  Validation of improved methods for predicting long-term elastomeric seal lifetimes from compression stress-relaxation and oxygen consumption techniques. , 2003 .

[24]  Libo Lin,et al.  Experimental research on aging and operating life of O-ring used in GIS , 2017, 2017 4th International Conference on Electric Power Equipment - Switching Technology (ICEPE-ST).

[25]  Xuerong Liu,et al.  Degradation of hydrogenated nitrile rubber (HNBR) O-rings exposed to simulated servo system conditions , 2017 .

[26]  S. G. Burnay,et al.  Prediction of service lifetimes of elastomeric seals during radiation ageing , 1985 .

[27]  Kenneth T. Gillen,et al.  An ultrasensitive technique for testing the Arrhenius extrapolation assumption for thermally aged elastomers , 1995 .

[28]  D. K. Ottesen,et al.  Oxidation profiles of thermally aged nitrile rubber , 1998 .

[29]  Lin Yang,et al.  A Review on Test Methods and Lifetime Prediction of GIS Seal Rings , 2018, 2018 International Conference on Power System Technology (POWERCON).

[30]  Robert Bernstein,et al.  Predicting and confirming the lifetime of o-rings , 2005 .

[31]  K. Gillen,et al.  Predicting the lifetime of fluorosilicone O-rings. , 2009 .

[32]  Lin Yang,et al.  Method of Determining Compression Set for GIS Seal Ring (O-ring) Based on Directional Section Diameter , 2019, International Conference on Electrical Materials and Power Equipment.

[33]  W. Lang,et al.  Sensor integration in rubber gaskets for structural health monitoring made by compression molding , 2015 .

[34]  K. Gillen,et al.  General solution for the basic autoxidation scheme , 1995 .

[35]  A. Cunliffe,et al.  Photo-oxidation of thick polymer samples—Part II: The influence of oxygen diffusion on the natural and artificial weathering of polyolefins , 1982 .

[36]  A. Ficheux,et al.  Limiting SF6 Gas Emissions by Optimization of Design and Testing of Gaskets in High Voltage Gas-Insulated Substations , 2012 .

[37]  K. Gillen,et al.  Accelerated aging and lifetime prediction: Review of non-Arrhenius behaviour due to two competing processes , 2005 .