PTFE缠绕垫片旋转法兰的强度及密封性能研究

Study on the Strength and Sealing Performance of Swivel Flange Joint with PTFE Spiral Wound Gasket

带垫片的螺栓法兰为压力容器管道的重要连接件,现行的基于Waters算法的规则设计难以保证法兰连接承受复杂载荷的完整性及密封有效性,根据欧盟标准BS EN 13445-3-2009附录GA的设计原则,建立PTFE缠绕垫片的压缩回弹本构关系,采用3D非线性有限元方法分析垫片及螺栓连接的旋转法兰组件受到内压及外载作用的强度及密封性能,结果表明螺栓预紧及操作条件下垫片法兰的密封性能及强度性能满足要求,螺栓预紧力的确定与内压及外载的大小,动态变化的垫片压应力、螺栓分散性有关。

The bolted, gasket circular flange joints are the important connection forms in pressure vessel pipelines. Existing i design rules based on Waters algorithm are hard to guarantee flange joints bear complex loadz of integrity and the sealed validity. According to EU standard BS EN 13445-3-2009 Appendix GA of design principles, the nonlinear compression elastic rebound behavior of PTFE spiral wound gasket is established. Using a nonlinear three -dimensional finite element analysis, the strength and sealing performance of flange joints, comprised of the swivel flange, the matched weld neck flange, bolts and trITE spiral wound gasket, are provided subjected to the inner pressure and external loads. Analysis results indicate that under the conditions of bolt preload and the operation, the strength of flange joints and the gasket sealing performanee can be accepted. Determines of bolt pretension force are related to magnitudes of inner pressure and the externally applied loads, the dynamic changes of gasket pressure and bolt dispersion.