| 摘要 |
<p>The invention relates to a butterfly valve assembly having a stationary valve body formed with an axial fluid flow passage opening and a turnable valve member adapted for full opening, partial opening and full closing of the said passage opening. There is provided further a valve seat ring composed of an inner protecting layer of fluoride containing resin and an outer back-up layer of rubber or its equivalent. According to this invention, at least two parallel ring grooves are provided on the radially outwardly directing surface of the said elastomer layer which has a substantially channel-shaped cross-section embracing a substantial part of the valve body when the valve seat ring is attached in position to the valve body. Further, each of both chords of the channel in its cross-section are opposingly bulged out inwardly at the both ends of each channel chord for creating and maintaining each a tongue-and-recess mode intimate connection between the valve body and the elastomer layer, when the valve seat ring is attached to the valve body. Still further, a small idle gap is formed in each of the inner corners of the channel for receiving occasional and radial physical deformation of the elastomer layer caused by repeated operation of the valve member.</p> |
