Innovation in Pipeline Intervention - Inflatable System for Linestopping Operations

Proceedings Publication Date:

01 Sep 2016
Patrick Fuß
Patrick Fuß, Nicole Schneider
Part of the proceedings of
Hottapping and Linestopping are reliable methods, available to the operators of pipeline-systems to execute maintenance- and repair-activities without shutdown. The system is being used since many years without significant changes in its principles. The execution is split into several steps: Initially a split-tee(s) is (are) usually welded to the pipeline. Then sandwich-type-valves are installed on the fittings and the Hottaps are being carried out. After completion of these operations the Linestopping equipment can be mounted. Up until now static sealing elements are being used on the Linestop-heads. Using these static elements it is not always possible to guarantee a 100% seal. For safety reason a secondary barrier is being installed as well, to ensure safe management of any leakages. Those leakages occur most of the time due to ovality in the pipe, weldseams and deposits on the pipe wall. The currently used static seal can not always compensate these parameters. The system under development utilises inflatable sealing elements, which can be adjusted to suit the conditions better and therefore a better seal can be achieved. The system is laid out in a way that would require least as possible modifications on existing equipments. It is intended to carry out initial field tests towards the end of 2010.