Research On The Effect Factors Of Compression-resilience Performance Of Flexible Graphite Metallic Spiral Wound Gasket

Flexible graphite metallic spiral wound gasket is a kind of static sealingelement applied widely, wounded alternatively with metal belt of certainsection shape and nonmetal belt, and it, flange and bolt compose a staticsealing connecting structure having wide application in petrochemical andpower industries.Form1960s, flexible graphite metallic spiral wound gasket was broughtinto china with the large-scale introduction of refinery equipments, and so far,the production scale and production capacity have met basically the need inrelated industries. But in the view of practical production and application,irregularity of performance of flexible graphite metallic spiral wound gasketexists, especially under standard in compress-resilience performance whichdangers the safety of equipment operation, there being many reasons such asbackward production process and equipment, lack of effective theoreticalguidance and confusion in reference to standards and so on.Mechanical properties of flexible graphite metallic spiral wound gasketis one of the important guarantees to flange-bolt-gasket seal connecting structure, and compress-resilience performance is significant to flexiblegraphite metallic spiral wound gasket. The formation of initial sealingcondition depends on compress property and seal performance underoperation state mainly depends on resilience performance.As the development of petrochemical industry to equipment enlargingand harsher working condition parameters, it will be one of the possiblefactors that the performance problems are the limitation of petrochemicalindustry development, so it is significantly necessary to make technicalinnovation for flexible graphite metallic spiral wound gasket. Consideringthat the compress-resilience performance flexible graphite metallic spiralwound gasket depends mainly on its structural characteristics and productionprocess, so it is of practical significance to standardize production process,promote performance and its stability, and ensure the equipment operatingsteadily that conducting study on effect factors to compress-resilience offlexible graphite metallic spiral wound gasket.In this paper, research is done on compress-resilience performance offlexible graphite metallic spiral wound gasket by theoretical analysis,numerical simulation and testing.First, the simplified mechanical model of flexible graphite metallic spiralwound gasket is established, and mechanical analysis of the gasket is madeunder axial load which is to find the effect factors to compress-resilienceperformance of flexible graphite metallic spiral wound gasket, and the study shows that compress-resilience performance of flexible graphite metallicspiral wound gasket depends structure parameters, process parameters andmaterial characteristics, moreover, these factors interact each other to impactthe stiffness, strength, stability, compressibility, resilience, stress relaxationand sealing performance.Besides, mechanical characteristics and deformation properties areanalyzed of flexible graphite metallic spiral wound gasket bycomputer-assisted method and compress-resilience performance of flexiblegraphite metallic spiral wound gasket is obtained. It shows that the curvesform numerical simulation has a similar trend with the ones from testing, butthere are some numerical differences between them, due to the limitation ofnumerical simulation software and complexity of inner stress conditioncompress-resilience performance of flexible graphite metallic spiral woundgasket.Finally, the experiments are conducted that flexible graphite metallicspiral wound gasket with different structure parameter, process parameter andmaterial parameter in compress-resilience performance by comprehensiveperformance test machine of gaskets, and density of flexible graphite belt,winding impact force, inner cycle number of metal belt and outer cyclenumber of metal belt are selected as factors. It indicates that the compressionratio will reduce and resilience ratio will increase when the density of flexiblegraphite belt or winding impact force level up; the influence of inner cycle number of metal belt and outer cycle number of metal belt are not obvious.According to the influent factors on compress-resilience of flexiblegraphite metallic spiral wound gasket in practice, research is conducted byoptimized its production process parameters, material properties and structureparameters，so as to promote its compress-resilience performance and providetechnological basis for performance lifting of flexible graphite metallic spiralwound gasket, standardizing and normalizing of production process withengineering significance.