Metallic Expansion Joints consist of prefabricated bellows that absorb thermal expansions and vibrations, hold parts together, allow movements as well as to compensate misalignments. They consist of one or more metal bellows at both ends. They are differentiated according to the three basic types of movement which are axial, angular and lateral movement. Metallic Expansion Joints are good for withstanding high pressures and a wide variety of temperatures from high to cryogenic. Additionally, it may be used for a variety of thermal movements, has very little upkeep, and is combustion-free.
There are several parameters required to design an Expansion Joint:
Simplest form of expansion joints used for axial movement in pipe configurations
Universal Expansion Bellows consists of two bellows connected by a common connector. It’s able to absorb large amount of lateral deflections and compensate axial and angular movements.
Single Hinge Expansion Joint consist a single bellow with a pair of hinges which permits angular deflections in one plane.
Gimbal Type Expansion Joint consist of two pairs of hinges connected to a common floating ring which allows absorption of angular deflections in any planes.
Elbow Type Pressure Balance expansion Joint are utilized where there are changes of direction in piping systems. This keeps the effective displacement of the assembly NIL by virtue of constant volume maintained during operation.
Inline Pressure Balance expansion Joints absorbs the axial and lateral movement while restraining the pressure thrust.