| 摘要 |
<p>A closure for a pipe or pressure vessel comprises a door adapted to fit into an aperture in a pipe or pressure vessel and an arcuate locking member disposed around the periphery of the door for locking the door to the pipe or pressure vessel, the ends of the locking member being movable towards and away from each other to cause radial expansion and contraction of the locking member, whereby the locking member is brought into and out of locking engagement with the pipe or pressure vessel. A seal for the closure comprises a rigid,usually annular, support having first and second flanges for engaging respective opposed faces on the closure and the pipe or pressure vessel, the first flange having a greater surface area and being less flexible than the second flange, and a flexible lining carried by the support and extending beyond the terminal edges of the flanges.</p> |
