| 摘要 |
In a steam valve, a seat-side convexly curved surface (35b) of a valve body (30) is configured such that the average radius of curvature Rv from a starting end portion (35c) on the upstream side in a flow direction of steam to a termination end portion (35a) has a relationship of Rv<Rs with respect to the radius of curvature Rs of a valve-seat-side convexly curved surface (26a); the seat-side convexly curved surface (35b) is formed with an upstream-side curved surface (36) and a downstream-side curved surface (37); the seat-side convexly curved surface (35b) has an abutting area (35s) abutting a valve seat portion (26); and the radius of curvature R1 of the downstream-side curved surface (37) has a relationship of Rs<R1 with respect to the radius of curvature Rs in the flow direction of the steam. |
