Axial movement is the change in dimensional length of the bellows from its free length in a direction parallel to its longitudinal axis.
Lateral movement is the relative displacment of one end of the bellows to the other end in a direction perpendicular to its longitudinal axis.
Angular movement is the rotational displacement of the longitudinal axis of the bellows toward a point of rotation. Torsion refers to twisting one end of the bellows with respect to the other end, about the bellows centerline.
Rubber expansion joints isolate or reduce vibration caused by equipment. The transmission of vibration is reduced and they protect equipment from these adverse effects.
Rubber expansion joints tend to dampen transmission of sound because of the steel rubber interface of joints and mating flanges.