| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealing structure of a gate valve whose gasket ring can easily be attached between a valve casing and a valve casing cover. SOLUTION: In this gate valve, a valve casing cover 28 is arranged for covering an upper end opening of a valve casing 22. The openings of the valve casing 22 and the valve casing cover 27 have elliptic forms. A valve casing flange 30 of the valve casing 22 is abutted against a cover flange 31 of the valve casing cover 27. In such a case, the valve casing 22 is casted by precision casting using a sublimation pattern, to form an elliptic groove-like recession 32 on the abutting surface of the valve casing flange 30, along a peripheral edge of the opening. A gasket ring 33 which is in press-contact with the abutting surface of the cover flange 31 is arranged in the recession 32.
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