Abstract: A method of plugging a pipeline includes the steps of welding onto the exterior of the pipeline (10) first (12) and second (14) spaced apart collars, each having a sealing face (26,26A) in a plane perpendicular the pipeline (10) axis. A containment housing (34,36) is affixed by welding to the collars (12,14) to fully encompass a section of the pipeline (10) between the collars (12,14). A tapping (60) machine is then removably attached to an open top of the containment housing (34). Using the tapping machine (60) a short length of the pipeline (10) is cut and removed from between the collars (12,14) leaving two open exposed pipe ends (78,80). First and second seal elements (92,94) are positioned between the collars (12,14), Each having a forward sealing face. The seal elements (92,94) are forced apart from each other into sealing engagement with the collar sealing faces thereby closing the open, exposed ends (78,80) of the pipe (10).

Abstract: A carrier is disclosed for holding an optical lens blank while forming optical surfaces on the blank. The carrier includes a clamp for holding the periphery of the lens blank while exposing a central area of the blank. An outer peripheral surface and one of two spaced end surfaces on the carrier are used in a method for locating and positioning said carrier/lens blank in a lathe, milling machine or other machine tool such that the exposed lens blank surfaces may be precisely and accurately cut to form optical lens surfaces with minimal error or misalignment. Holders for mounting the carrier in a lathe or milling machine and having locating surfaces engaging the outer peripheral and one end surface on the carrier are also disclosed.