Seat Ring with Insert for Butterfly Valve, and Manufacturing Method Thereof

摘要

The present invention provides a seat ring with insert for a butterfly valve enabling improved valve seat sealing performance, valve stem sealing performance, and flange surface sealing performance, and enabling the easy and secure alignment of a valve stem in the manufacture of the seat ring and in the assembly of a valve body, and a method for manufacturing the same. A seat ring with insert for a butterfly valve configured so that an annular insert is fitted on the outer peripheral surface of the seat part in which there is provided a valve body fitting annular groove having side wall parts on both the upstream side and downstream side, wherein there are provided on the outer peripheral surface of the insert a step so that the outer diameter on the downstream side is smaller than the outer diameter on the upstream side and on the inner peripheral surface a locking projection, and the insert is fitted in the annular groove provided in the valve body fitting annular groove of the seat part.