Application of Large-Diameter Butterfly Valves for High-Temperature Flue Gas Treatment at a Copper Smelting Enterprise

A large copper smelting enterprise employs a flash smelting process in which the flue gas exiting the smelting furnace reaches temperatures as high as 550°C and contains highly corrosive gases, such as sulfur dioxide. The flue gas must pass through a waste heat boiler for heat recovery before entering the acid-making system; consequently, a large-diameter butterfly valve is required between the waste heat boiler and the electrostatic precipitator to manage gas flow switching and system isolation. Traditional gate valves suffer from severe deformation and slow closing speeds under such high-temperature, corrosive conditions, failing to meet the requirement for rapid shut-off during emergencies. The enterprise selected our DN1800 high-temperature butterfly valve; both the valve body and the disc are constructed from 310S heat-resistant stainless steel, enabling stable, long-term operation at temperatures up to 600°C. Our valve features an elastic seat design that automatically compensates for differential thermal expansion, a valve shaft with a hollow cooling design and specialized heat dissipation components, and sealing elements made from a special graphite composite material capable of withstanding temperatures up to 800°C. When the acid-making system requires maintenance, our valve transitions from fully open to fully closed in just 12 seconds—significantly faster than the 30-plus seconds required by comparable products—thereby effectively preventing the risk of flue gas leakage. The valve has operated continuously and stably at the facility for five years, requiring only two routine maintenance sessions during that period; it has become a core component of the enterprise’s high-temperature flue gas treatment system, fully demonstrating the reliability of our products under extreme operating conditions.