The invention relates to a
flue gas valve, and discloses a sealing structure for a rotary shaft of a
flue gas valve. The sealing structure comprises a packing
pipe. A pressing ring, first buffering rings, a compression spring, a
graphite sealing ring and second buffering rings which are sequentially butted to one another are arranged in the packing
pipe, an inner rib is arranged at one end of the packing
pipe, an outer rib is arranged at the other end of the packing pipe, an outer
flange is arranged at the end, which is far away from the first buffering rings, of the pressing ring and is connected with the outer rib by assembling bolts, an adjusting gap is reserved between the outer
flange and the outer rib, the second buffering rings are butted to the inner rib, the outer
peripheral surface of the
graphite sealing ring is hermetically connected with the inner
peripheral surface of the packing pipe, the
flue gas valve comprises the rotary shaft, the rotary shaft is penetratingly arranged in the
graphite sealing ring and is hermetically butted to the graphite sealing ring, matching surfaces of the rotary shaft and the graphite sealing ring are conical surfaces, and small-
diameter ends of the conical surfaces are close to the inner rib. The sealing structure for the rotary shaft of the
flue gas valve has the advantages that a shaft end of the rotary shaft of the
flue gas valve can be sealed by the sealing structure, and sealing effects can be adjusted; the problem of leakage at a shaft end of an existing
flue gas valve can be solved by the aid of the sealing structure.