Integral hydro-bulge forming of single and multi-layered spherical pressure vessels

The recently developed integral hydro-bulge forming (IHBF) process was utilized in the manufacturing of single and multi-layered spherical pressure and storage vessels. Single-layered spherical vessels of 1.6-mm thickness and diameters of 316.5, 634.1, and 953.2 mm were manufactured. As an alternative means of manufacturing thick-walled spherical pressure vessels, the IHBF procedure was modified and used informing double-layered composite pressure vessels with an effective thickness of 15 mm. The results showed that the modified IHBF process may successfully be applied in the manufacturing of multi-layered spherical vessels of various thicknesses and diameters. In this paper, the conventional and modified IHBF procedure will be outlined and the experimental results and analysis will be presented. Finally, areas where further work is needed are identified.