... (DI, CI, SS) PTFE Coated3.Stem: SS4.Seat: PTFEOur PTFE lined butterfly valve adopting the PTFE butterfly board to sealed spherical ... surface, being equipped with silicon rubberCushion in the seat is flexible, perfect on sealing ... applied to carry the liquids and gas (include the vapor) with strong corrosion,such as sulfuric acid, rofluoric acid, phosphoric ...