| 摘要 |
<p>A pre-formed flexible protective liner characterized by its durability, resistance to corrosion, and inherent self-lubricating qualities, is disposed between the body bore and the valving member of a butterfly valve; and resilient back-up means are provided between the body bore and liner for yieldably expanding the liner into fluid-tight sealing relationship with the valving member periphery when in closed position.</p> |
