The descriptions and models of the equipment: HJ-GKA50 can be used to manufacture double-buckled expansion pipes with the diameter from Φ25 to Φ50; HJ-GKA125 can be used to manufacture double-buckled expansion pipes with the diameter from Φ65 to Φ125; HJ-GKA200 can be used to manufacture double-buckled expansion pipes with the diameter from Φ30 to Φ150. Applications: The expansion pipes can be widely used for automobile,petro-chemical industry,steel,construction and electrics etc.based on different materials and diameters.