To provide a butterfly valve provided with a water charging function in which manual operation to a valve element is light in a small opening range smaller than a water charging opening, so that the water charging opening can be easily and correctly sensed and grasped by an operator.
Fins 30A and 30B to shield pass of fluid F in the small opening range smaller than the water charging opening are provided at an outer circumferential part of the valve element 2. On the outer circumferential part of the valve element 2, a sealing protrusion 4 to get in contact with a valve box seat 1A of rubber in a total closure state is formed. At tip parts of the fins 30A and 30B, a sealing protrusion 5 to get in contact with the valve box seat 1A in the water charging opening of the valve element 2 is formed. Outer surfaces 30a and 30b of the fins 30A and 30B between the sealing protrusion 4 and the sealing protrusion 5 are composed to face an inner surface of the valve box seat 1A of rubber at an interval t.
SATO KEIICHI
HOURAI AKINOBU
FUJIYAMA HIROSHI
KUBOTA KK
Shoji Suzue