Telescopic butterfly valve with automatic compensation for thermal expansion and contraction of the cold loading and unloading functions, used in the temperature below 425 ℃, the nominal pressure of 1.6MPa below the oil, chemical, power, papermaking, water supply and municipal construction and other industrial pipe for regulation flow And the best device for breaking the fluid. ã€Features】 1, unique structure, flexible design, light weight, labor-saving, quick opening and closing. 2, Retractable butterfly valve can not only compensate for the thermal expansion and contraction shrinkage caused by the pipe temperature difference, the sea can provide convenient for the maintenance of the valve installation and replacement. 3, sealing parts can be adjusted replacement, sealing performance and reliable.