Expansion joints flexible elements

Generally expansion joint flexible elements have a buildup of ... 

The flexible element of GT expansion joints should be designed to withstand the full gas temperatme without the aide of an insulation pillow. However it is common practice to install a fuU-cavity insulation pillow for the foDowing reasons ... 

Typically at the HRSG inlet the expansion joint sees the vertical growth of the boiler, which can be as much as 150 to 200 mm. Inexperienced suppliers wotdd try to use one single expansion joint for this application but in fact no individual flexible element should be asked at these elevated temperatures to absorb more than 60-75-mm lateral movement. The materials of the expansion joint start to crease or fold in the vertical side walls as the joint absorbs the lateral movement. As the folds become more and more pronounced the external materials of the joint are prevented from being cooled by the ambient air, heat builds up, and the joint fails prematurely. 

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