摘要 |
<p>The process aids the installation of pipelines in trenches of which the sides are retained by a fluid such as bentonitic slurry (2). It entails the creation of low pressure in a previously installed section (1) of the pipeline, the effect being used to pull the succeeding element (13) into position to form a joint. The opening (6) of the first installed section is plugged (7,8,9) and a plug (7) aperture is connected (10) to a low pressure source. The succeeding section (13) is lowered into the trench, one opening (13A) being located beside that (6) of the primary section (1), and its remaining openings being provisionally plugged (16). Low pressure is now created in the first section and is used to pull the second section into place.</p> |