| 摘要 |
PROBLEM TO BE SOLVED: To provide smooth water cut-off performance without causing reduction of a communication area. SOLUTION: In the metal seat butterfly valve V, a thin elastic metal made cylindrical valve body seat 6 is provided in an inner face of a valve body 1, and contact and separation of a valve element 3 is carried out with respect to the valve body seat 6. In the valve body seat 6, its both ends 7 whole circumferences are cross sectionally U-shaped, and it is housed in a recessed part 4 of the valve body inner face. By this housing, a protruding amount to the valve body inner face due to installation of the valve body seat can be minimized, and reduction of the communication area is prevented. If both ends 7 are U-shaped, when the valve element 3 abuts on a substantially center of the valve body seat 6 (when the valve is closed), moment protrusively bending a center part from the U-shaped ends toward a valve body center acts like a statically indeterminate beam with respect to the abutting force, the moment enhances the abutting force of the valve element, and the water cut-off performance becomes high. Water cut-off into the recessed part 4 is carried out by an O-ring 8, and abutting force during deformation absorption of the valve body and valve closing is eased by elastic rubber 9 of recessed part 4 both ends. COPYRIGHT: (C)2006,JPO&NCIPI
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