Air distributor piping

Figure 4-51. Air distributor— pipe grid design version. (Source Enpro Systems, Channelview, Texas.)...

The fatigue crack in the gusset plate attachment resulted in large stress concentrations. With a highly cyclic service, the fatigue crack initiated and resulted in the eventual failure of the air distributor pipe. The use of abrupt geometric boundaries on surfaces is not good practice in cycUc service because of stress intensification. 

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