... , stainless steel, Cr .Mo .SteelSeal ring: Stainless steel, multi-layer asbestos with temperature resistantStem: Stainless steel, Cr .Mo . ... , corrosion resistant, wear resistance long lifetime. StructureThe series of multi-layer metal-to-metal butterfly valve is the new ... dimensional principle, the compatible to soft sealing and metal multi-layer structure, with best machining and advanced technology. ...