Abstract: An apparatus for inserting a shut-off device 9 laterally into a pipe via a branch 48 which is inclined at an obtuse angle to the pipe, comprises a housing 1 for connection at one end to the branch and containing a first carriage 6 which is movable relative to the housing to a forward position projecting from the housing into the pipe and includes a receptacle for the shut-off device and a guide member 8 for guiding the shut-off device out of the receptacle, a second carriage 10 which is movable relative to the first carriage and is connected to the shut-off device by an insertion jack 13, and displacement means for first moving the first carriage to its forward position, the second carriage moving with the first carriage, and for then moving the second carriage relative to the first carriage to move the shut-off device out of its receptacle further into the pipe, the insertion jack finally being operated to move the shut-off device into position in the pipe.

Abstract: The invention concerns the removal of a concrete covering applied to an underlying surface provided with an anti-corrosion coating, for example that of a hydrocarbon-conveying pipe.The coating is removed by making trenches in the concrete to divide it into removable elements, the trenches being made using a cylindrical milling cutter having a longitudinal diamond-faced toothing and provided with a central stud of tungsten carbide projecting axially from the end of the cutter. In use the stud contacts the surface to prevent the surface being damaged by the toothing on the cutter as the cutter is moved transversely across the surface. To initiate a concrete covering removal operation, a hole is first drilled through the covering perpendicular to the surface for receiving the stud. The cutter is then moved perpendicularly to the surface through the concrete with the stud projecting into the drilled hole and until the stud contacts the surface.