| 摘要 |
PROBLEM TO BE SOLVED: To fix a valve casing of a valve casing valve seat 14 and to adjust a projecting margin by a seat keeper 20 (fixing member of valve seat 14) without degrading sealability.SOLUTION: In a butterfly valve, a valve seat 14 with which an outer peripheral face of a valve element 12 is closely kept contact, is disposed on an inner peripheral face of a valve casing 11, and a seat keeper 20 is disposed in adjacent to the valve seat to press the valve seat in valve casing radial direction a and axial direction b. The seat keeper is composed of a fixing member 21 disposed in adjacent to the valve seat to press the valve seat to the valve casing radial direction and to fix the same on an inner face of the valve casing, and a projecting margin adjustment member 22 of the valve seat disposed in adjacent to the fixing member to press the fixing member to the valve casing axial direction. After mounting the valve seat in a valve casing groove 11a by the fixing member, the projecting margin adjustment member is fitted to the groove 11a and a bolt 25 is screwed. Thus the fixing member is moved in the valve casing axial direction through a clearance gap 26, and the valve seat is compressed and projected from the inner face of the valve casing. That is, the projecting margin of the valve seat is adjusted on the basis of a compression degree. |
