This series is a sealed gas butterfly valve, using soft rubber seal. The length of the structure using standard wafer butterfly. For the convenience of users, the valve flange connection can also be used. The valve has a simple structure, easy maintenance, sealing and reliability. The valves are suitable for gas, air and other gases do media pipeline regulation and closure purposes. Widely used in industrial gas, municipal gas and environmental protection, ventilation systems. The valve connecting flange dimensions conform to GB2555-81 standards. Detection methods conform GB/T13927-92 standards.