Applying single-seat structure and lining the King of Anti-corrosion teflon material on inner chamber of valve, the valve ensures the part contacting media is of teflon material. With features including good corrosion resistance, small volume, light weight, stable operation and high reliability, the valve is widely applied in working conditions involving different strongly corrosive media (such as hydrochloric acid, chlorine and sulfuric acid) in petroleum industry, chemical industry, metallurgi