| 摘要 |
Pipeline stopping tools for use in temporarily stopping flow in a pipeline have features for centering a conduit or cable within the pipeline. The conduit or cable is guided into a recess, to avoid damage as the pipeline is squeezed closed. Alternative pipeline stopping stools have features for sealing against both the inside walls of the pipeline and against the cable. In a first tool, a linkage on a handle drives seal lips on a seal ring to engage around and seal against the cable in the pipeline, while the outer edges of the seal ring seal against the inside walls of the pipeline. The linkage includes jaws which force the seal lips against the cable. In a second tool, a resilient seal is attached over a center plate and side plates pivotably attached to the center plate. A linkage drives the center plates from an open to a closed position. A cable recess in the seal ring seals against the cable while the outside edges of the seal ring seal against the pipeline. A third tool has a resilient plug and lips positioned around a cable recess. As the plug is forced into the pipeline, the lips seal around the cable, and the plug sidewalls bulge outwardly to seal against the pipeline.
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