| 摘要 |
<p>A device blocks the flow of fluid in a pipe so that work can be done on the pipe downstream of the device. The device includes an installation unit and a blocking unit. The installation unit is sealed against the ambient when mounted on the pipe to permit drilling a hole into the pipe and the blocking unit includes an expandable body which is passed through the installation unit and on through the hole in order to temporarily block the flow of fluid in the pipe. The expandable body has a larger diameter than the internal diameter of a channel in the installation unit. The blocking unit includes a rod mounted in the holder to which a manual force is applied for distending the expandable body before insertion so that the expandable body has a diameter less than the diameters of both the channel and the hole thereby facilitating passage of the expandable body through the channel and hole into the pipe. The manual force is released and the rod is then withdrawn so that the expandable body assumes its initial shape within the pipe. Air under pressure can be applied to the expandable body so that the body tightly plugs the pipe thereby permitting work to be done on the pipe.</p> |
