| 摘要 |
<p>The oilfield tubular pin and box connection includes double shoulders (16, 22). An inner sleeve (18) engages the box at shoulder (20), and provides one of the two shoulders (16, 22) for engaging the pin. The pin bore optionally may be provided with a similar sleeve (24), thereby providing one of the shoulders for engaging the box. The sleeve (18) may be secured to the box shortly after its manufacture, or may be added as a retrofit to an existing box with a single shoulder.</p> |
