Weifang Zhongyun Group is a hi-tech private enterprise with more than 40 years experiences of manufacturing high quality plastic pipe equipment and wind generator, and is the leading manufacturer for machinery and electricity in China. It has three companies named Weifang Zhongyun Machinery Co., Ltd; Weifang Swisselectric Co., Ltd. and Weifang Zhongyun Scientific & Research Co., Ltd. There are 680 employees and three production bases.　　It covers 440,000 sq meters of area and 280,000 sq meters of building area, it has more than 100 sets of processing units, including more than 40 sets of planer type process centers with digital control with international advanced technology. Zhongyun was certified for quality system of ISO 9001 in 1998. It can offer a complete service on product design, manufacture and after-sales care. Zhongyun has received many awards in recognition of its using advanced technology and superior management． 　　As a top manufacturer, Zhongyun has devoted itself to developing new technology on machinery and electricity for many years, acting in close cooperation with China Science and Research Institute, Beijing Chemical Industry University and Hsinghua University. There are more than ten advanced key technologies and 30 patents developed in Zhongyun. Many awards were conferred for the technologies and extrusion lines for PE/PP/PVC Corrugated Pipe, Al-plastics Composite Pipe, PP-R Pipe, One Step PEX Pipe and UHMW-PE Pipe.　　In the recent years, plastic piping with big diameters has been popularized in the drainage and sewerage along with the enhancing support of policies on environment protection and water saving. The extrusion lines for PE/PP/PVC Double Wall Corrugated Pipe and PE Steel Spiral Corrugated Pipe are new research achievements in Zhongyun. The new products especially for the extrusion lines for PE/PP/PVC-500, 1000, 1500 Double Wall Corrugated Pipe, combining Chinese and international advanced technology. Through consummating and innov