| 摘要 |
IN A THREADED JOINT FOR STEEL PIPES COMPRISING A PIN (1) AND A BOX (2), EACH HAVING A THREADED PORTION (11 OR 21), A SEALING SURFACE (13 OR 23), AND A SHOULDER SURFACE (14, 15 OR 24, 25), THE SEALING SURFACE (13) OF THE PIN (1) IS FORMED BY A TAPERED SURFACE, AND THE SEALING SURFACE (23) OF THE BOX (2) IS FORMED BY A FIRST CURVED SURFACE PORTION WITH A LARGE RADIUS OF CURVATURE IN THE RANGE OF 15-120 MM, A TAPERED SURFACE PORTION, AND A SECOND CURVED SURFACE PORTION WITH A LARGE RADIUS OF CURVATURE AGAIN IN THE RANGE OF 15-120 MM. (FIG. 1) |
