CPC F16K 1/222 (2013.01) [F16K 1/2014 (2013.01)] | 8 Claims |
1. A valve disk of a double eccentric butterfly valve, the valve disk having a circular outer shape and comprising:
a boss section for accommodating a stem; and
a rib section extending toward both outer edge portions of the valve disk in a direction intersecting the stem from the boss section,
wherein the boss section and the rib section are provided on a surface on one side of a disc, and a stem center axis passing through a center of the stem is at a position shifted from a valve disk center axis,
wherein the boss section is divided into a plurality of boss sections such that the stem is partially exposed, the rib section is provided in each of the boss sections obtained by the division, and the rib section and the boss section are consecutively connected to each other such that there occurs no step in a height direction viewed from the surface of the disc and there occurs no linear boundary portion on a side wall surface of the boss section, and
wherein the boss section is divided into two boss sections such that the stem is exposed in the vicinity of a center of the valve disk, the rib section is formed nearer the center side of the valve disk in each of the boss sections, and a sidewall surface, on the center side of the valve disk, of the boss section and a sidewall surface, on the center side of the valve disk, of the rib section are provided to form a consecutive single plane.
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