Abstract: In welded pipe manufacturing a steel strip is fed and bent by forming rolls into a pipe. A load detector is provided for a roll rotary shaft of each forming roll; a forming roll inclination adjustment device inclines the roll rotary shaft. The roll shaft load is measured to cause inclining of the rotary shaft counterclockwise or clockwise on a plane formed by the rotational axis of the forming roll and the advancing direction of the steel strip.

Abstract: A roller width adjusting device for a divided molding roller has a hollow main shaft journalled at each end to side bearings so as to be rotatable around a rotary axis thereof. The hollow main shaft is connected at one end to a driving source for rotating the main shaft around the rotary axis. A pair of hollow cylindrical roller holders are disposed on an outer periphery of intermediate portions of the main shaft so as to be slidable along the rotary axis of the main shaft. The roller holders may be fixed in any position along the rotary axis by a holding device. A pair of divided type molding rollers are attached to the roller holders, respectively. An adjusting shaft is rotatably disposed in the hollow shaft along its rotary axis. Each end of the adjusting shaft has a screw thread with opposed screw directions. One end of the adjusting shaft has a rotatable handle.

Abstract: A board of calcium silicate crystals, characterized in that the board is composed of a plurality of layers of laminated thin sheets, each of the thin sheets having a thickness of 2 mm or less, each layer comprising secondary particles of calcium silicate crystals, a fibrous material, a coagulant and preferably additionally a polymer adsorbed on the surface of the secondary particles of calcium silicate; wherein each layer contains secondary calcium silicate particles interconnected with one another, and wherein the superposed thin sheets are firmly united with one another into an integral body by the interlayer interconnection of secondary particles of calcium silicate crystals present on the surface of the sheets.

Abstract: A board of calcium silicate crystals, characterized in that the board is composed of a plurality of layers of laminated thin sheets, each of the thin sheets having a thickness of 2 mm or less, each layer comprising secondary particles of calcium silicate crystals, a fibrous material, a coagulant and preferably additionally a polymer adsorbed on the surface of the secondary particles of calcium silicate; wherein each layer contains secondary calcium silicate particles interconnected with one another, and wherein the superposed thin sheets are firmly united with one another into an integral body by the interlayer interconnection of secondary particles of calcium silicate crystals present on the surface of the sheets.

Abstract: The present invention is a machine for manufacturing welded steel pipes, in which an edge bending roll for constraining under pressure a strip from its pipe edge portions to the boundaries between the pipe edge portions and its pipe side portions to bend the strip, a first center bending roll for constraining under pressure the pipe side portions to bend the pipe side portions, second to fourth center bending rolls for constraining under pressure the strip from the boundaries between the pipe side portions and its pipe bottom portion to the pipe bottom portion and applying lateral pressure to the pipe from both sides to bend the boundaries and the pipe bottom portion and a plurality of cage rolls arranged on both the sides of these center bending rolls, first and second fin pass rolls for further forming under pressure the pipe, are arranged in order from the stream side to the downstreamside of a roll forming process.