Expansion joints

Axial expansion joints (AR)

Axial bellows expansion joints are designed to accomodate compressive or extension movements along the bellows longitudianl axis. Movements available are usually specified as +- amounts from free length. The free length is the theoretical length before movement. From this free length the unit will provide an equal amount of movement in either extension or compression. Therefore, to utilise all the movement will be in one direction only, it is recommended that units are installed with either pre extension or pre-compression, dependent upon the pipe movements.

Care is required during installation to ensure that the unit is installed at its correct length so that it will only work within its specified limit. Any deviation would have a detrimental effect upon the bellows life. It should also be ensured that axial units are adequately anchored and guided. Axial bellows are supplied flanged or with pipe ends suitable for welding into pipelines, or as a combination of both.