Mandrel to be inserted into a liquid circulation pipe and associated positioning method

摘要

This mandrel (10) comprises a body (16; 22) and a radially expandable annular sealing element (18) which comprises a centring arrangement (46) and a closure arrangement (44) which can be deployed radially between a contracted configuration and a dilated configuration. It further comprises an anchoring element (20) which is positioned at a longitudinal distance from the sealing element (18) and is radially expandable between a retracted state and a deployed state. The mandrel (10) comprises sequencing means (24) which are capable of radially deploying the closure arrangement (44) after the anchoring element (20) and the centring arrangement (46). In an at least partly deployed configuration, the centring arrangement (46) defines at least one axial passage (64) which extends through the annular sealing element (18). The closure arrangement (44) closes the or each axial passage (64) as it is deployed.