| 摘要 |
<p>Subterranean service pipes, eg. water mains, are tapped by minimal excavation to expose the upper half of the main and then locating (with respect to the main) a conventional pipe-tapping device but without employing means encircling the pipe. Thus, a clamp can be used, or a saddle adhesively secured to the pipe. The clamp or saddle preferably provide means for proper orientation of the drilling and tapping tool with respect to the main.</p> |
