The utility model relates to an improved butterfly valve, in particular to a hard seal butterfly valve with a compound layer on an inclined cone table surface, which is suitable for opening, closing, or throttling high, low pressure, and high and low temperature media flowing through a pipeline.
In the prior art, there is a Chinese patent "Metal Hard Seal Butterfly Valve" (ZL95203441.7) technology, which is composed of a disc with a tapered surface as the sealing surface and a tire-shaped elastic valve seat as a seal; by adjusting the gasket Adjust the elastic valve seat to ensure the reliability of its tightness. However, the use of a non-circular tapered surface as the sealing surface and the sealing surface of the tire (round) surface can not form a uniform sealing profile, and it is not reliable to rely on the deformation of the elastic valve seat to seal. In addition, it is difficult to completely compensate the sealing surface shape and position error due to the change of the adjusting gasket, especially when the pressure of the medium is large, the valve port will inevitably leak.
The purpose of this utility model is to overcome the above-mentioned technical deficiencies, and provide a hard seal butterfly valve with a compound layer on an inclined cone table surface, using a hard seal valve seat with an internal inclined cone table compound layer, and a butterfly plate equipped with the inclined cone table as a sealing surface. Make it into high, low pressure and high, low temperature sealed butterfly valve.
The purpose of the present utility model is to realize a kind of hard seal butterfly valve with a compound surface of an oblique cone table, which has a valve body, a valve stem, a butterfly plate and a valve seat. It is characterized in that the butterfly plate has a sealing surface with an oblique cone table surface, the valve seat is a composite layer with an inner oblique cone table sealing surface, and the inner and outer oblique cone surfaces cooperate to form a seal. The lower end surface of the valve stem and the end cover plate The cylinder head support seat on which the gasket, the screw and the screw are mounted on the valve body are connected. On the ideal plane formed by the midline mn of the maximum long radial thickness of the plane of the butterfly plate and the midline AQ there, the angle B of the oblique cone The angle bisector and the perpendicular AQ form a γ angle. The distance from the center (line) O of the valve stem to the perpendicular AQ is E and the distance to mn is H. In the ideal plane, it appears as a right triangle. side. The diameter of the butterfly plate at mn is Do. During operation, the valve stem is opened from the seal at the minimum angle of the ideal plane oblique cone, and the valve opening is opened, and the valve opening is gradually increased with the rotation of the valve stem until the butterfly When the diameter of the plate and the pipe is 90 °, the valve opening is the largest, and the action is the opposite when closing.
Compared with the prior art, the utility model has the advantage that since the metal butterfly plate adopts the oblique cone table sealing surface and is equipped with the oblique cone table sealing valve seat in the composite layer, the seal is formed. Therefore, the sealing fit and the shape are matched without leakage. This hard-sealed sub-structure can withstand high-temperature, high-pressure, low-temperature, and low-pressure working media, and has a small rotating torque, low friction, long working life, and convenient operation. It is also possible to compensate the wear of the long-term working seal profile with a modified composite seal seat.