1. The hinged type constrains the internal pressure thrust by the hinge arm and hinge pin mounted on the sides of the bellows and absorbs the expansion and contraction by bending the bellows. 2. Since the internal pressure thrust is constrained by the hinge, the load is not applied on the fixing point. 3. The weight of the intermediate pipe is supported by the hinge arm so that it does not affect the bellows. 4. The hinge type does not need the fixing point so it can reduce the piping...