Abstract: An exhaust gas pipe has a wall and a connecting piece fastened to it. A functional part, such as a probe, is received into the connecting piece. The connecting piece has a formed-on, unworked protrusion for fastening the functional part.

Abstract: A tube junction is produced having at least two inlets and an outlet, and at least one bend between the two inlets by providing a forging die with a first recess contoured to hold a bent tube piece. A second recess opens into the first recess and, terminates in a moveable counterpunch. A tube piece having two inlets is bent to bring the two inlets into positions relative to each other generally similar to relative positions of the inlets in a finished tube junction. The bent tube piece is placed within the forging die, and pressurized internally to bulge the tube piece wall into the second recess and form a neck for the outlet. Motion of the counterpunch away from the first recess is controlled as the neck forms under pressure in the second recess.

Abstract: An emission control system for internal-combustion engines has a purifying insert which is arranged in a housing by way of an intermediate layer and whose inflow-side front side is subjected to a diagonal flow by way of an inflow pipe, to achieve a simple connection of the inflow pipe and the housing, the inflow pipe has a section which represents a boundary around the insert downstream of its front side and is used as a connection with the housing.