The raw material of SBG(B) bellows is HDPE, its corrosion performance is far superior to that of metal, it is not afraid of acid, corrosion resistance, it does not corrode itself, and can effectively protect the prestressed tendon from corrosion. The SBG(B) plastic bellows provide a barrier protection that is far superior to that of metal bellows, which can prevent the pollution of harmful substances penetrating through the pipeline, thus ensuring better durability of the prestressed structure.