The system thermal expansions are the differential expansion/contraction of operating and/or excursion temperatures and the minimum ambient temperature during installation and shutdowns. The expansion joint engineer uses these movements and temperatures to select the proper material and design for each expansion joint. UNAFLEX®’s non-metallic expansion joints frequently can handle combined axial, lateral, angular and torsional movements in a single assembly.
The expansion joint locations can often be optimized, reducing the total number required. Consideration should be given for accessibility and belt replacement, for new ducting for the duct fabricator to provide a portion of the expansion joint frame.
|Lateral Movement||Axial Compression/Extension|
|The amount of duct movement occurring in either or both of the two perpendicular planes to the longitudinal axis of the duct, which moves the expansion joint flanges out of axial alignment.||The dimensional shortening (compression) or lengthening (extension) of the expansion joint face-to-face dimension parallel to its longitudinal axis.|
|Torsional Deflection||Angular Deflection|
|The amount of twisting movement (in degrees) occurring in the perpendicular planes to the longitudinal axis of the duct system||The amount of rotation (in degrees) of the duct system which flexes the expansion joint flanges out of parallel position with each other.|