Butterfly Dampers

Butterfly dampers are a simple and cost-effective method for controlling and isolating gas flows in industrial applications. They consist of a circular disc that rotates on a central shaft within a cylindrical housing. When fully open, the disc is parallel to the flow, allowing gases to pass through. When closed, the disc rotates perpendicular to the flow, blocking it.

Typically made of carbon steel or stainless steel, butterfly dampers can be manufactured from specialized alloys for extreme temperatures or corrosive environments. They can be actuated pneumatically, electrically, or manually via a hand lever or gearbox. Sealing arrangements, including seal air fans, can be incorporated to achieve the required sealing efficiency.

Butterfly dampers are commonly used in low pressure applications but can be designed for higher pressures as PED compliant valves. They can handle temperatures up to 600°C standard, or 1250°C for specialized designs. Sizes typically range from DN300 to DN3000.

Key features include a fully welded body, compact design, and ability to handle on/off or modulating control. Optional extras like maintenance-free bearings, standardized flange connections, flexible metallic seals, and refractory lining for hot processes can be added. Common applications include exhaust systems, air ducting, gas mixing, and tunnel ventilation.

Butterfly dampers provide a versatile solution for flow control and isolation across many industrial segments including power generation, oil and gas, marine, and general industrial processes.