??? Hongda Filter Factory of Gongyi city in Henan Province of China are a professonal filter material manufacturer who owns powerful technology, best quality equipment, advanced technique and 18 years production history. Our finished products includes eight series and hundreds kinds and was in front rank of same industries, and it is also nationalwide chemical and thermotechnical design technological centre unit. Our product had been catalogued into 2008 Edition Water&Wastewater Engineer ...