Welded butterfly valve with precision j-shaped elastic ring and three eccentric multi-level metal hard seal structure, it is widely used for regulating flow rate and carrying off fluid in gold treatment, electric power, petrochemical industry, water supply and drainage, municipal construction and other industrial pipelines with medium temperature ≤425 °C. Welded butterfly valve is divided into cast steel welded butterfly valve, stainless steel welded butterfly valve, chromium-molybdenum steel welded butterfly valve, welded butterfly valve using three eccentric structure, seat and disc sealing surface are made of different hardness and stainless steel, with good corrosion resistance, long service life, the valve can have two-way sealing function, products in line with the national GB/T13927 -92 valve pressure test standards.