Preventing the damage of the bellow expansion joint due to tortuous stress is an important link in the construction of thermal pipelines. The bending moment of the heating network bellow expansion joint is affected by the following factors. In the construction of thermal pipelines, it is inevitable that there will be varying degrees of concentricity errors or laying stresses, which will cause the thermal pipelines in operation to deviate from the planned position.

Therefore, the thermal pipe network bellow expansion joint will be subjected to varying degrees of tortuous stress during operation, which affects the normal operation of the pipeline, and even shortens the service life of the thermal pipe network bellow expansion joint, leaving hidden dangers to the safe operation of the thermal pipeline.