| 摘要 |
<p>The disc for a butterfly valve is circular. It has a shaft bore and a diametrical axis. The leading half faces upstream when the disc is inserted in a valve, and includes two surfaces diverging from the most leading portion of the peripheral edge towards the bore, forming a wedge facing upstream. The trailing half including two diverging surfaces extending from along portions of the disc adjacent the bore towards the most trailing portion of the peripheral edge. The disc has a maximum thickness located in the leading half forward of and adjacent to the axis of the shaft bore.</p> |
