Forming-die-free integrated stub-end manufacturing process using spinning

• Published in: International journal of precision engineering and manufacturing 2016-05, Vol.17 (5), p.679-684
• Main Authors: Gwak, Gi-Yeol, Cho, Jong-Rae, Choi, Jin-Young, Kim, Jae-Soo
• Format: Article
• Language: English
• Subjects: Engineering; Industrial and Production Engineering; Materials Science
• ISSN: 2234-7593; 2005-4602
• DOI: 10.1007/s12541-016-0083-z

Stub ends are used to connect pipes in piping arrangements and are generally manufactured by welding two sub-components. This welding process is time consuming and causes pollution. Stub ends can also be produced without welding via a general spinning process using thicker pipe; however, the production cost is high, because different forming dies must be prepared in order to obtain various stub end sizes. Material loss also occurs. A flexible manufacturing process that does not use forming dies is proposed in this paper. The stub-end shape is formed by rolling dies instead of an outer mold. During this process, the lap roller motion is dependent on the required degree of forming. To determine the effects of the process parameters and to identify the optimal process, a commercial finite-element-method (FEM) code, DEFORM Ver. 11.0, is employed here. The lap-guide and lap-roller movement speeds are the main process parameters. Based on the simulation results, a 3-inch stub end meeting the ASME B16.9-2007 code requirements is fabricated. After production, the forming load is examined and the measured pressure on the ring roller is found to agree with the calculated value. The dimensions of each part of the stub end also satisfy requirements.