Flexible expansion joints for absorbing thermal expansion, the reduction of vibrations and preventing stress in pipe systems. The expansion joints have a type approval from Det Norske Veritas, Germanischer Lloyds and ABS. Bellows are optional from the following materials listed in the material information table. Among the various types of bellow materials, we introduce the specifications of the most standard type Model 5570 for your ordering guidance as follows. Model 5570, Bellow Material: Internal – Nitrile, External – Chloroprene