corrugated pipe machine/corrugated pipe equipment /pipe extruder/corrugated pipe line plastic machinery/plastic machine/plastic pipe machinery/plastic pipe machine/plastic pipe extrusion line/spiral pipe extruder, plastic pipe extruder/pipe extruder, pipe machinery, pipe machine Weifang Zhongyun Science and Research Co., Ltd. is a holding subsidiary company of Zhongyun Group. Its current main scope of business is various kinds of large, medium and small sized PE/PVC/PP double wall corrugated pipe equipment with horizontal water cooling system for high speed running