TEE CONNECTION TO A PIPELINE

摘要

A method is provided for securing a branch assembly(1)to a "live" pipeline(6).An upper part(2)of the assembly incorporating the branch(13)is positioned on the pipeline over a first containment ring/annular seal arrangement(16/17)and a second containment ring/annular seal arrangement(116/117)spaced from the first arrangement to leave an annular gap(118)therebetween.A lower part 3 of the assembly is positioned on the pipeline beneath the upper part and the two parts are secured together so that the seals are compressed.An access point(119)allows the monitoring of the pressure in the annular gap(118)to check for seal integrity of the inner seal(17).If pressure is detected,as a result of leakage of fluid via the branch(13)past the seal(17)the vent can be closed so that the second seal(117)becomes effective.