Working Principle and Structural Features of Pneumatic PTFE-lined Butterfly Valve

The  pneumatic  lined butterfly valve is an Automatic Control Valve specifically designed for corrosive media. Its working principle combines the driving force of pneumatic actuation with the simplicity of butterfly valve structure. When compressed air is input into the pneumatic actuator, the reciprocating motion of the piston or diaphragm transmits force to the valve stem, causing the butterfly plate to rotate around the central axis. The butterfly plate rotates from the closed position (fully contacting the seat) to the open position (aligned with the pipeline flow path), achieving medium flow control. The rotation angle typically varies between 0° and 90°, ensuring rapid and reliable opening and closing operations.
In terms of structural characteristics, the pneumatic PTFE-lined butterfly valve places special emphasis on corrosion resistance. Both the inner wall of the valve body and the surface of the disc are lined with fluoroplastic materials such as polytetrafluoroethylene (PTFE), which exhibit excellent chemical stability and can resist erosion from various strong acids, alkalis, and solvents, effectively protecting the valve body from medium corrosion. The main body of the valve is cast or forged from high-quality metal, ensuring mechanical strength and durability, while the precision machining of the lining guarantees a reliable sealing effect, maintaining stable sealing performance even under temperature conditions (typically ranging from -50°C to 150°C).   
In addition, the pneumatic fluorine-lined butterfly valve features a flexible flange connection design, facilitating installation and maintenance. The valve body is typically designed as a two-piece structure, enabling on-site inspection and lining replacement. The actuation device not only provides the necessary power but may also be equipped with a manual override mechanism to accommodate manual operation in case of automatic system failure. Overall, the  pneumatic  fluorine-lined butterfly valve plays a pivotal role in industries such as chemical and pharmaceutical manufacturing, owing to its exceptional corrosion resistance, ease of operation, and extended service life.