Abstract: The invention relates to a device intended to be introduced into a pipeline for circulating a fluid and comprising an operational element, a central connecting rod and a plurality of radial lugs, these lugs being linked to the operational element by means of the connecting rod and extending, under the effect of an elastic force, like umbrella spokes, to press against the inside of the pipeline. According to the invention, the lugs are spaced regularly around a same fitting, and the elastic force is at least partly constituted of a turning torque applied to the lugs through support means constituted, for example, by an axial spring pushing a stop washer mounted to slide on the connecting rod.