... specification 20 25 32 40 50mm. 4.Full down line. Two Cavity Pipe Extrusion Line :1.Use conical twin screw extruder, capacity optional. ... for barrel screw to maximum the performance of extrusion.3.This PVC pipe extrusion line is designed with our new advanced technology and ... PVC pipes, PVC flame-retardant pipes,water drain-off pipes, irrigation pipes, sound-proof drain-off pipes,(foam-core pipes and ...