Abstract: A pipe-bending press with a large bending length in a closed frame construction, has a frame with side columns and upper and lower cross-pieces. The table supporting the lower bending tools is supported at the lower cross-piece and the upper bending tool which is guided vertically at the side columns in a parallel manner is supported via a plurality of identical piston/cylinder units arranged side by side so that the upper bending tool can be raised and lowered relative to the upper cross-piece. The cylinder spaces of the piston/cylinder units are connected to a common pressure medium unit via a common control line, and the lower piston/cylinder units are arranged between the table supporting the lower bending tools and the lower cross-piece.

Abstract: A mechanical pipe expander having a pyramidal, polyhedronal cross-section, segments resting against the pyramidal surfaces which are displaceable in axial direction relative to the polyhedron, and grooves formed in the longitudinal centers of the edges of the polyhedron so that the side surfaces of the grooves represent guides for the correspondingly shaped segments. The segments are formed as dove tails on the leading end thereof over a length of about 5-30% of their total length and each of the side surfaces of the dove tail recesses slide on a side surface of two adjacent grooves formed in the polyhedron. The length of the grooves is limited to the path of displacement of the polyhedron with respect to the segments, and the ends of the segments facing away from the leading end are held by radially acting springs against the surfaces of the polyhedron.