| 摘要 |
The present invention relates to a control device for the throughput in a conduit portion, comprising a valve or a flap composed of a body mounted on a rotary support shaft and being displaceable between a position of maximum closure and a position of minimum closure by pivoting about said shaft.Device characterised in that at least one shape or structure (4, 4') which is at least partially obstructive, projecting into the internal passage of said conduit portion (1) and locally reducing the passage section thereof, is present in the region of the internal face of the wall (1) of said conduit portion (1) and comprises at least one cooperating surface zone (5) which intimately mates with the shape of at least one art of the imaginary surface swept by at least one segment of the external peripheral edge (6) of the body (2) of the valve or flap when pivoted.
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