368111-A is referenced by 1 patents.
368,111. Making compound pipes and hollow-ware. KRAUSS, R., 24, Borsigstrasse, Breslau, Germany. April 11, 1931, No. 10691. [Classes 83 (ii) and 83 (iv).] Stamping.-Pipes or tanks are made from tubes, comprising rolled plate welded along the seam, by expanding one by fluid pressure into another of greater diameter and smaller length. A tube 3 is held between members 1, 2 which may form part of a testing machine, and fluid pressure is introduced at 6 to expand the tube into an outer one 4, the end portion 7, Fig. 2, being subsequently removed. A series of tubes may be expanded into the interior of a composite tube so formed. The seams of the tubes 3, 4 are preferably on opposite sides, and the diameter of the tube 3 is initially 20 per cent less than that of the tube 4.; Tanks are formed in a similar manner by securing an endplate either to the final tube or to each tube before the operation, covers being afterwards provided.