Working Principle and Application Areas of High-temperature Butterfly Valves

High-temperature butterfly valves are devices used to control fluid flow and regulate volume under high-temperature conditions. They utilize a butterfly disc as the closing element, which rotates approximately 90 degrees to open or close the valve. Key components include the valve body, butterfly disc, valve stem, high-temperature sealing materials, and electric actuator. The electric actuator receives control signals and drives the valve stem, thereby rotating the butterfly disc. In high-temperature applications, the valve material must withstand prolonged thermal stress, while the sealing mechanism must prevent leaks caused by thermal expansion.

 Compared to other high-temperature valves such as gate valves or ball valves, butterfly valves have distinct structural features. Gate valves rely on vertical movement of the gate to block the flow; however, their sealing surfaces are prone to wear at high temperatures, and they require longer time to open and close. Ball valves use a rotating sphere to control the flow, but torque requirements increase significantly in large-diameter pipes at high temperatures. Butterfly valves, with their lighter and thinner butterfly discs, experience less fluid resistance during rotation, requiring less driving force for the same diameter. This results in lower energy consumption in high-temperature, high-flow systems. Their shorter overall length also makes them suitable for installation in spaces limited by high-temperature pipelines. High-temperature resistance is a crucial characteristic of electric high-temperature butterfly valves. Valve bodies and butterfly discs are typically made of heat-resistant alloy steel or stainless steel, such as 310S or 304H, which maintain mechanical strength and creep resistance even under continuous high temperatures. Sealing materials often include metal hard seals or flexible graphite composite structures. Metal seals achieve tight contact at high temperatures through precisely manufactured seal surfaces, but require high precision in fabrication. Flexible graphite seals utilize their high-temperature resistance and self-lubricating properties to compensate for thermal deformation. Unlike ordinary rubber or PTFE seals, these materials do not deteriorate rapidly in environments exceeding 300 degrees Celsius. Electric actuators are responsible for driving and controlling the valve. 

They typically consist of a motor, reduction gear, position feedback device, and control module. The motor provides rotational power, while the reduction gear converts high-speed low-torque motion into low-speed high-torque motion to drive the valve stem. Position feedback devices like potentiometers or encoders monitor the butterfly disc’s opening angle and transmit signals to the control system. Compared to pneumatic or hydraulic actuators, electric actuators do not require additional air sources or hydraulic stations, eliminating maintenance issues related to compressed air dehydration or hydraulic oil leakage in high-temperature environments. However, electric actuators must also have appropriate temperature resistance or incorporate insulation measures to prevent overheating of internal components. In industrial applications, high-temperature butterfly valves are commonly used to control fluids at high temperatures. In thermal power generation, they regulate steam flow in pipelines to meet turbine requirements. In metallurgical industries, they control the flow of hot gases in blast furnace gas pipelines or heating systems. Chemical plants also use these valves in cracking units and reactor heating systems. Compared to standard butterfly valves, high-temperature versions feature specially selected materials, optimized designs, and improved heat dissipation mechanisms to handle continuous or intermittent high-temperature conditions.