Patent ID: 7637478
Filing Date: 2009-12-29
Classification: F16K,Y10T

Abstract:
1. A seat ring assembly for a butterfly valve wherein the butterfly valve has a valve body which has an inner peripheral surface to be engaged by the seat ring assembly, the seat ring assembly comprising: a seat part member having an outer circumferential surface defining an annular groove having an annular groove base circumferential surface, and an upstream side wall and a downstream sidewall opposing one another; an annular insert member having an upstream end, a downstream end, an annular insert interior circumferential surface extending between the upstream end and the downstream end, and an annular insert exterior circumferential surface extending between the upstream end and the downstream end, the annular insert member being fitted in the annular groove of the seat part member with said annular insert interior circumferential surface engaging said annular groove base circumferential surface; the annular insert exterior circumferential surface in combination with the upstream sidewall and the downstream sidewall of the seat part member comprising a valve body fitting annular groove having the upstream sidewall and the downstream sidewall of the seat part member extending radially outward beyond said annular insert exterior circumferential surface to form sidewalls of the valve body fitting annular groove, the valve body fitting annular groove being configured to conform to the inner peripheral surface of the valve body; said annular insert member defining opposing first valve stem openings extending radially through the annular insert and said seat part member defining corresponding opposing second valve stem openings aligned with said first valve stem openings and configured for accepting a valve stem; said annular insert exterior circumferential surface including a step extending circumferentially around said annular insert exterior circumferential surface so as to intersect said first valve stem openings, said step being circumferentially continuous with exceptions of the first valve stem openings, said step being oriented so that a downstream outer diameter of the insert member on downstream side of the step is smaller than an upstream outer diameter of the insert member on an upstream side of the step; and a locking projection being provided on the annular insert interior circumferential surface.