... (material used: superior ceramic, Colmonoy coated,Tungsten carbide coated wear resistant and anti-corrosive layer).Packing seal: Aramid fiber ,Kevlar ... ARN valve ,spherical valve and combined valves.They are wear resistant and anti-corrosive after special treatment.All series of ... maintenance, safe and reliable sealing, long life in easy-wear parts, high volumetric efficiency,etc. On the base of ...