... water, land and air. Specialized in development and production of copper valves, gas valves, cast steel valves, stainless steel valves, ... ) Co.,Ltd, which is Top 500 enterprises and the largest copper processing manufacturer in China, with more than 5000 staffs and annual ... requirements.(4)Steady raw material supply: our parent firm has copper bar company .(5)Seven Step QC Process 1) Material Control ...