... Materials Comapny and Sino-SouthKorea Joint Venture Henan Changmao Yuanyi Valve Co.,Ltd , we specialize in the enquipment of ... ISO 9001 :2008 international system of quality control.Products reach nearly one hundred series, thousands of specifications, ... expansion joints etc.Registered trademark "Changmao" brand, selling products throughout 31 provinces, municipalities and autonomous regions, was used ...