Product Discharge System’s Pipe Stress Analysis And Fatigue Strength Assessment

Product discharge system (PDS) is an important system unit in the reaction areaof linear low density polyethylene (LLDPE) plant applying Unipol processtechnology of American Univation Co. The piping in the system receives pressurecirculation and high frequency impact load at high temperature, resulting in easydamage that will cause accident. Complete stress analysis and fatigue strengthassessment of the piping system is a key point for the technology to realizeindustrialization. This article performed analysis and study for the piping of theproduct discharge system, including dynamic calculation (covering the calculation ofthe inherent frequency of piping system and Time History analysis) and assessment offatigue strength, in addition to static calculation (covering the primary and secondarystress calculations, force calculations of equipment nozzles and check of flangeairtightness).