The simplest type of expansion joint consists of a single bellows element welded to end fittings, normally flange or pipe ends. The single bellows can absorb small amount of axial, lateral and angular movement. The addition of tie rods to a Single Bellows assembly adds design flexibility to a pipe system. The tie rods are attached to the pipe or flange with lugs that carry the the pressure thrust of the system, eliminating the need for main anchors.
