| 摘要 |
A plug 10 for sealing a conduit (90, Fig 5) comprises a seal 20 in the form of a stack of frusto-conical washers 22 energised and de-energised by relative movement between first and second body sections. As the stack of washers 22 is energised by being compressed by relative movement between a housing 14 and a plug mandrel 18, a laminate (48, Fig 15) of softer material between each washer 22 is squeezed radially inwards, forming a seal with a plug mandrel 18, and radially outwards, forming a seal with the conduit 90. As the plug mandrel 18 moves in a release direction, a pressure equalising flow path is created around the seal 20. |
