| 摘要 |
<p>A seal assembly for sealing across the annulus in a subsea wellhead having pressure enhancement provided behind at least one of the sealing surfaces to ensure a positive metal-to-metal sealing. In a preferred form of the invention the seal assembly 20 min includes upper sealing lips 30, 30a, 32, 32a, which diverge upwardly away from each other into sealing engagement with the sealing surfaces against which they are to seal, lower sealings lips 38, 38a, 40, 40a, which diverge downwardly away from each other into sealing engagement with the sealing surfaces against which they are to seal, and one or more rims 58, 60, 62, 64 secured to one of the wellhead members and spaced therefrom to provide a recess behind the rim and open to pressure which is directed toward the sealing lip which is to seal against such sealing surface to provide a pressure energized enhancement of the sealing engagement of the lips against said sealing surface. In other forms of the invention at least one of the rims may be used.</p> |
