This production line is used for producing foamed PVC pipe, the production of the core layer foamed pipe widely used in water pipe, electric power pathways communication, cable ducts, the airport road and rail drain, low hole irrigation, such as delivery, the whole production line mainly has: SJSZ65/132 conical twin-screw extruder (crowded core layer), SJSZ55/110 conical twin-screw extruder (internal and external layer), mold crowded, vacuum sizing box, cooling water tank, tractor, cutting machine, piled up rack of single.