| Flexible graphite covered wave-serrated metal gaskets are widely used in the bolted flange connection under low temperature because of its excellent mechanical performance and sealing performance, and good results are obtained. The materials of flexible graphite covered wave-serrated metal gaskets are able to withstand high temperature and its structure is excellent, so it has been a trend that flexible graphite covered wave-serrated metal gaskets are used in bolted flange connection under high temperature and high pressure. However, there are requirements only on thickness of flexible graphite covered wave-serrated metal gaskets in GB/T19066.1-2008.Now the structure parameters of flexible graphite covered wave-serrated metal gaskets are designed by manufacturers, it causes variable quality of gaskets and brings great potential safety hazard to the enterprise. Seriation and standardization of flexible graphite covered wave-serrated metal gaskets is a problem and needs to be solved. In addition, the study on high temperature performance of flexible graphite covered wave-serrated metal gaskets is almost blank. The mechanical properties of flexible graphite covered wave-serrated metal gaskets mainly depends on the metal frame, therefore, studying on mechanical properties of metal frame is valuable and significant to make it be applied in petrochemical enterprises broader and more safely.Based on GB/T19066.1-2008, metal frames of different width are studied using numerical simulation method. The reasonable gasket structure is obtained according to the amount of compression、the distribution of stress and deformation. The deformation and stress distribution of metal frame are correct because of the reasonable boundary conditions. Metal frame has good mechanical properties in following conditions:teeth depth is almost1/3of metal frame thickness; teeth number is3.5when gasket width is less than or equal to10.5mm, teeth number is4when gasket width is greater than10.5mm.The maximum displacement is in the tooth top of metal frame. The maximum stress is in the wave trough and the minimum stress is in the tooth top region. With the increase of wave number, axial displacement decrease; With the increase of wave tooth depth, axial displacement increase. The influence degree of wave number on axial displacement is larger than tooth depth.In this paper, high-temperature creep properties of flexible graphite covered wave-serrated metal gaskets metal frame are studied using numerical simulation method. It shows that metal frame has good high-temperature creep resistant performance. The creep strain in the trough is the largest and in the tooth top area the minimum, the difference in values is very large. With the increase of load, creep strain level increases exponentially. Under the conditions of low load, the area of large creep strain is less, creep has less effect on the metal frame; Under the conditions of high load, the area of large creep strain is large, creep has very big effect on the metal frame.The other aspects of flexible graphite covered wave-serrated metal gaskets under high temperature and high pressure are introduced. Under the condition of high temperature, creep relaxation will cause leakage failure and creep damage accumulation will cause fracture failure. Under pressure fluctuating condition, creep-fatigue interaction is more complex than single creep or fatigue. The gasket life under creep-fatigue interaction is much smaller than the linear additivity of creep damage and fatigue damage. The relevance of graphite and metal frame has a great influence on creep damage and fatigue damage of metal frame. In addition, the high temperature stability of the binder should be noticed.Flexible graphite covered wave-serrated metal gaskets is a kind of good performance、easy installation and very economical gaskets. The mechanical properties of metal frame are studied and it has great value and significance to enterprise and the society. |
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