| 摘要 |
<p>In a broad aspect, the invention relates to an improved downstop seal (100) for use with a rod-piston actuator (40) of a surface controlled subsurface safety valve (10) wherein the rod-piston actuator (40) has a beveled shoulder (160) formed thereon. The improved downstop seal (100) has a resilient, primary, sealing member (110) having a beveled sealing surface to matingly engage with a portion of the beveled shoulder of the rod-piston actuator (40); and further has a non-resilient, secondary, sealing member (120) having a beveled sealing surface to matingly engage with a portion of the beveled shoulder (160) of the rod-piston actuator.</p> |
