Blisters / Deformation / Ply Separation
Some blisters and deformation when on the external portions of an expansion joint may not adversely affect the performance of the expansion joint. These blisters or deformations are cosmetic in nature and do not require repair. If major blisters, deformations and/or ply separations or delaminations exist in the tube, the expansion joint should be replaced as soon as possible. The root cause of delamination is either over-torque bolts, chemical attack by the media, aged rubber or some other form of break in the inner tube layer. Corrective actions include replacing the aged rubber expansion joint and ensuring the correct material selection for the application.