Triple eccentric metal seal butterfly valve designs in triple offset construction. The laminated seal or metal to metal seal makes the valve can be used for high temperature and high pressure working condition with long service life and energy saving. The triple eccentric metal seal butterfly valve is designed as a device to shut-off or regulate the working medium flow and widely installed in industrial pipelines with corrosive medium in metallurgy, iron and steel industry, power plant, petroleum, chemical industry, heat supply, inflammable gas, municipal water supply and drainage and etc. As the latest technology achievement, triple eccentric butterfly valves provide a variety of connections to meet different face to face dimensions, such as wafer type, lug type, flanged type, ring-joint type, butt-welded type and jacketed type. It is suitable for acid, alkali and other corrosive medium at both high and low temperature due to wide material selection. Especially in large-diameter butterfly valve, it is continuously replacing the shut-off valves such as gate valve and ball valve with its advantage of zero leakage; meanwhile it is also continuously replacing the regulating valves such as globe valve with its excellent performance in regulation and control.