Precision forming of flange for a large special vessel

The processes of precision forming of a flange for a large special vessel and a large pressure vessel are introduced in this paper. The common characters of these manufacturing processes are: (a) final precision machining was completed in the construction site with a multifunctional machine tool; (b) the flange was prepared from six or subparts in a conventional plant without joints; (c) precision assembly and welding of the subparts after transporting them to the construction site was performed to secure a solid ring before machining.