Bellows expansion joint (compensator) is an expansion joint made of metal bellows. It can stretch along the axis direction and also allow a small amount of bending. it is a common axial bellows expansion joint, which is used for axial length compensation on the pipeline. In order to prevent exceeding the allowable compensation amount, a protection rod or a protection ring is arranged at both ends of the bellows, and a guide bracket is arranged on the pipes at both ends connected with it. In addition, there are corner type and transverse expansion joints, which can be used to compensate the corner deformation and transverse deformation of the pipeline. The advantages of this kind of expansion joint are space saving, material saving, convenient for standardization and mass production, and the disadvantages are short life. Bellows expansion joints are generally used for pipes with low temperature and pressure and short length. With the improvement of bellows production technology, the application scope of this kind of expansion joint is more and more wide.
