Abstract: The invention relates to a device for blocking a flow in a pipeline under pressure, comprising a clamp member (1) for encasing a section of the mantle surface of the pipeline and comprising a pipe socket (2) with a valve (17), switchable between an open and a closed position, and a hole-making tool (3) for producing a hole (56) in the mantle surface during sealing between the tool and the pipe socket. A blocking means (4) is adapted to be inserted through the produced hole and to expand in the pipeline for the purpose of blocking the flow in the pipeline. The blocking means consists of a body with a cross-sectional dimension which is less than the cross-sectional dimension of the hole, and a support member being guided in the pipe socket. Two sliding elements, which are carried by the body, are via the support member adjustable from the outside between an open position in which it is retracted into the body, and an expanded blocking position, in which it seals against the inner circumference of the pipeline.

Abstract: Method and device for mounting a body in a conduit containing fluid. An installation unit is mounted on the fluid at that place, where the mounting of said body is desired, whereby sealing is established against the environment around an area, where a hole is going to be made in the surface of the conduit. The hole is made in the conduit in said area maintaining sealing against the environment. A body is inserted through the hole, so that the body will be placed in the conduit.