Industrial Flue Gas Desulfurization Butterfly Valve The industrial flue gas desulfurization (FGD) butterfly valve is a critical component in power plants, chemical processing facilities, and other industrial applications where sulfur dioxide (SO₂) emissions must be controlled. Designed to regulate or isolate the flow of flue gases in FGD systems, these valves ensure efficient and reliable operation while meeting stringent environmental regulations. Design and Construction FGD butterfly valves are engineered to withstand highly corrosive and abrasive environments. They are typically constructed from high-performance materials such as duplex stainless steel, super duplex stainless steel, or nickel-based alloys to resist corrosion from acidic flue gases, chlorides, and other aggressive media. The valve body, disc, and seat are designed for durability, with special coatings or linings (e.g., PTFE, PFA, or rubber) to enhance resistance to chemical attack and erosion. The valve features a robust disc that rotates 90 degrees to modulate or shut off gas flow. The disc is mounted on a shaft supported by bearings to ensure smooth operation under high differential pressures. Sealing performance is critical, so advanced seat designs—such as resilient seats or metal-to-metal seals—are employed to minimize leakage and extend service life. Operational Performance FGD butterfly valves are designed for both throttling and shut-off applications. Their low-pressure drop and quick actuation make them ideal for large-diameter flue gas ducts. They can handle high temperatures (up to 500°F or higher, depending on materials) and pressures while maintaining tight shut-off (e.g., ANSI Class VI leakage standards). Actuation options include manual hand levers, gear operators, or automated actuators (electric, pneumatic, or hydraulic) for remote control and integration with process automation systems. Automated valves often include position feedback and fail-safe mechanisms to ensure operational safety. Applications in FGD Systems In wet FGD systems, these valves control the flow of limestone slurry, absorber tower gases, and treated exhaust. In dry or semi-dry FGD processes, they manage reagent injection and flue gas bypass. Their ability to handle slurries, particulates, and corrosive gases makes them indispensable in maintaining system efficiency and compliance with emission standards. Advantages - Corrosion Resistance: High-grade materials prevent degradation in harsh environments. - Low Maintenance: Robust construction reduces wear and extends maintenance intervals. - Energy Efficiency: Minimal flow restriction lowers energy consumption. - Compact Design: Lightweight and space-saving compared to gate or globe valves. Conclusion Industrial FGD butterfly valves play a vital role in reducing harmful emissions while ensuring reliable process control. Their advanced materials, sealing technologies, and operational flexibility make them essential for modern air pollution control systems. Proper selection, installation, and maintenance are key to maximizing performance and longevity in demanding FGD applications.