3 Conclusion By improving the sealing structure of the thermal insulation pneumatic ball valve, the sealing performance is excellent, especially the improved flexible graphite replaces the O-ring, which is widely used at 425 ℃. With the development of domestic industrial level and technological progress, its performance will continue to improve and its application scope will continue to expand. The insulated pneumatic ball valve is improved, designed and manufactured according to the market demand. The valve has the characteristics of compact overall structure, convenient operation, reliable sealing and long service life. At present, the insulated pneumatic ball valve operates well under the user's working conditions, and all performance indicators meet the design requirements. It has excellent performance for liquid medium with easy solidification and high viscosity, especially suitable for thick medium such as rosin.

Pneumatic ball valves are widely used for fluid control or regulation control in natural gas, oil products, chemical industry, metallurgy, paper making, power, mining, printing and dyeing, biopharmaceutical, daily chemical, food and beverage, water treatment, air treatment and other industries, and are used together with automatic pneumatic instruments.