| 摘要 |
A butterfly valve comprises a closure member 8 having a warped curve periphery pivotably disposed within a tubular body 1. An elastic seal and a cooperating seat are provided on the closure member and tubular body, respectively, or vice versa. At each point of a mean line of seat, a plane T tangent to the seat forms a roughly constant acute angle x of 20 DEG to 30 DEG with a tangent t to the path of the corresponding point of the closure member at the point of contact of the seal and seat. |
