Abstract: The basic principle and main procedures of the dieless hydro-bulging spherical vessels, as well as the research progress and the applications in engineering, are introduced. Theoretic analysis and the graphic description are made for the hydro-bulging of ellipsoidal shells. Experimental research on the integrated hydro-bulge forming of ellipsoidal shells is carried out, and the occurring position and expanding of the plastic deformation are also analyzed by using FEM results.

Key words: Dieless bulging, Ellipsoidal vessel, Hydro-bulging, Spherical vessel