Non-sealed butterfly valve
AssigneeCkd Corporation
InventorsChiharu INOMATA, Nobuhiro Fukukawa, Yasunori Nishimura
Life of this patent
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Abstract
In a non-sealed butterfly valve, a butterfly valve element includes maximum outer diameter portions facing the inner peripheral surface of a flow passage when the butterfly valve element is in a valve-closed position and first chamfered portions reducing the diameter of the butterfly valve element from the maximum outer diameter portions in a direction opposite a rotation direction of the butterfly valve element rotating from the valve-closed position to a valve-open position. The maximum outer diameter portions are provided point-symmetrically about the axis of a rotary shaft, and the first chamfered portions are provided point-symmetrically about the axis of the rotary shaft.
Claims18
A non-sealed butterfly valve to control pressure in a vacuum vessel, the non-sealed butterfly valve comprising:
- a flow passage;
- a rotary shaft placed extending in a direction perpendicular to the flow passage;
- and
- a butterfly valve element having a circular disk shape, coupled to the rod and configured to rotate about an axis of the rotary shaft, between a valve-closed position for minimizing a flow passage area of the flow passage and a valve-open position for maximizing the flow passage area,
- wherein the butterfly valve element includes:
- maximum outer diameter portions facing an inner peripheral surface of the flow passage when the butterfly valve element is in the valve-closed position and being provided point-symmetrically about the axis of the rotary shaft when viewed in an axial direction of the rotary shaft;
- and
- chamfered portions reducing a diameter of the butterfly valve element from the maximum outer diameter portions in a direction opposite a rotation direction of the butterfly valve element that rotates from the valve-closed position to the valve-open position and being provided point-symmetrically about the axis of the rotary shaft when viewed in an axial direction of the rotary shaft.
Dependencies are inferred from the claim text.