| 摘要 |
<p>A pipeline isolation plug for location in a section of pipe has two seal modules coupled together by a ball joint. The first module has a mandrel defining a pressure head which, in use, is exposed to the pipeline pressure. A seal element is mounted behind the pressure head and is radially extendable to engage a pipe inner wall. The second module has a mandrel defining a pressure head which, in use, is exposed to the fluid pressure between the first and second modules. Two axially spaced seal elements are mounted on the mandrel behind the pressure head and are radially extendable to engage the pipe inner wall.</p> |
