Patent ID: 7077383

Claim:
A butterfly valve for controlling a gas pressure, comprising: a valve housing having a longitudinal axis and defining a flow path for a gas along the longitudinal axis; a shaft having a rotation axis; a closure member connected to the shaft; the closure member being pivotally mounted in the valve housing for rotation about the rotation axis between an open position allowing the gas to flow through the valve housing and a closed position preventing the gas from flowing through the valve housing; the closure member consisting of a first disk and a complementary second disk which abut against each other, the first disk and the second disk being symmetrically arranged with regard to a symmetric axis extending at a predetermined angle of inclination (γ) to the rotation axis; the first disk and the second disk comprising each an inner surface, an outer surface, and at least one contact face abutting against a corresponding contact face of the respective other disk; and the contact face comprising a main portion extending parallel to the symmetric axis and at least one supplementary portion extending from an end of the main portion to the inner surface or the outer surface at a predetermined angle (α, β).