Pneumatic hard-seal butterfly valves represent long-life, high-quality butterfly valves designed based on the three-dimensional eccentric principle. They primarily consist of flanged or wafer-type hard-seal butterfly valves connected to pneumatic actuators. The valve seat and disc sealing surfaces are crafted from metal materials or stainless steel of varying hardness, offering advantages such as high-temperature resistance, corrosion resistance, and wear resistance. Featuring a multi-layer structure compatible with both hard and soft seals, these valves guarantee excellent sealing performance under both low and high-temperature conditions. The near-frictionless interaction between the disc and seat during opening and closing significantly extends the valve's service life. Widely used in pipelines carrying power, oil, steam, air, sewage, and other media, pneumatic hard-seal butterfly valves serve as optimal devices for on/off control or flow regulation.