VALVE SEAT RING FOR BUTTERFLY VALVE AND BUTTERFLY VALVE USING THIS

摘要

The present invention relates to a valve seat ring for a butterfly valve and a butterfly valve including the same. The vale seat ring for a butterfly valve is to reduce torque in accordance with rotation of a disk and improve airtightness between the disk and the valve seat ring. To achieve the purpose of the present invention, the valve seat ring for a butterfly valve seals a gap between a valve body and a disk rotating around a rotation shaft of the butterfly valve. The valve seat ring includes: a ring-shaped elastic attachment ring corresponding to the rotation of the disk, wherein the disk is attached to the ring-shaped attachment ring; a ring-shaped back ring enclosing the attaching ring; and a ring-shaped elastic shock absorbing ring pressed between the back ring and the valve body. The attaching ring includes: an elastic attaching unit protruding from the inner circumference to be attached to the disk; and a back-ring mounting unit formed to be dented on the outer circumference to insert the back ring. The back ring includes: an elastic protrusion unit protruding from the inner circumference toward the disk to be attached to the attaching ring; a shock absorbing groove unit formed to be dented on the outer circumference to be attached and inserted into the shock absorbing ring; and a back ring support unit individually protruding from an outlet of the valve and an inlet of the valve toward the valve body based on the shock absorbing groove unit. The shock absorbing ring includes: a shock absorbing base unit attached and supported on the valve body; and a shock absorbing protrusion unit elastically pressing the back ring in the shock absorbing base unit. A shock absorbing finishing unit is formed on the inlet of the valve and the outlet of the valve in the attaching ring to protrude toward the valve body to be separated from the inner circumference of the valve body.