| 摘要 |
A double-barrier metal-to-metal seal assembly includes a seal gasket (3) having an outer flexible seal element (6) and an inner flat rib (8). The assembly also includes a pair of hubs (4, 5) each having an internal machined profile characterised by a tapered profile (7) which, when the hubs (4, 5) are mechanically set, provides an interference fit against the outer flexible element (6) of the seal gasket (3) so as to provide an outer seal, and an inner profile (9) comprising a plurality of concentric circular nibs (9) machined on the hubs (4, 5) which, when the hubs (4, 5) are being mechanically set, progressively embed themselves (9) to a pre-determined depth into the rib (8) of the seal gasket (3) to effect an inner seal. The embedment is limited by the face-to-face abutment of the hubs (4, 5) outside the locus of the outer seal during the mechanical imposition of preload. |
