FGD System Butterfly Valve: Overview and Key Features A butterfly valve is a critical component in Flue Gas Desulfurization (FGD) systems, which are widely used in power plants and industrial facilities to remove sulfur dioxide (SO₂) and other pollutants from exhaust gases. The butterfly valve plays a vital role in regulating, isolating, or controlling the flow of slurry, gases, or other process media within the FGD system. Design and Construction FGD system butterfly valves are designed to withstand highly corrosive and abrasive environments. Key materials include high-performance alloys, rubber-lined bodies, or coatings such as epoxy or Halar to resist chemical attack. The valve consists of a disc mounted on a rotating shaft, which opens or closes by rotating 90 degrees. The disc can be designed in various configurations (e.g., concentric, double-offset, or triple-offset) to optimize sealing and durability. Key Features 1. Corrosion and Abrasion Resistance – The valve body and disc are often made of materials like duplex stainless steel, super duplex, or nickel alloys to handle aggressive slurries and acidic conditions. 2. Bubble-Tight Sealing – Resilient seats (e.g., EPDM, PTFE) or metal-seated designs ensure zero leakage, critical for environmental compliance. 3. Low Torque Operation – The lightweight disc design reduces actuation torque, enabling efficient operation with electric, pneumatic, or hydraulic actuators. 4. Compact and Lightweight – Compared to gate or globe valves, butterfly valves offer a space-saving solution with lower installation costs. 5. High-Pressure and Temperature Capability – Triple-offset designs are suitable for high-pressure/temperature applications, minimizing wear over time. Applications in FGD Systems - Slurry Handling – Controls limestone slurry flow in absorber towers. - Gas Isolation – Shuts off flue gas streams during maintenance. - Bypass Systems – Diverts gas flow when the FGD unit is offline. Maintenance and Reliability FGD butterfly valves require minimal maintenance due to their simple design. However, regular inspections of seals, discs, and actuators are recommended to prevent unexpected failures. In summary, the butterfly valve is an essential component in FGD systems, offering durability, efficiency, and reliability in harsh operating conditions. Its robust construction and adaptability make it a preferred choice for flow control in pollution control applications.