Black liquid ball valve is a high-performance valve designed for high temperature and strong corrosive medium conditions, especially suitable for paper making, chemical industry and other fields where the temperature exceeds 230℃ black liquid conveying system. The product uses an innovative graphite packing kit and O-ring free design, replacing traditional rubber seals with graphite gaskets, significantly improving acid and alkali corrosion resistance, ensuring excellent sealing effect under extreme conditions of high temperature black liquor. By optimizing the structure of the O-type ball valve and inheriting its excellent shutdown performance, the innovative use of fixed seat design effectively solves the problem of valve blockage caused by medium crystallization under high temperature conditions, and realizes easy opening and closing operation. Specially strengthened corrosion resistant components and structural design, so that the valve in the fluid accurate control ability on the basis of the delay of service life, is the ideal control solution for high temperature corrosive media pipelines.