1. Mutual superimposing results of edge stress and membrane stress make fairly total stress at edge reduce, so edge stress need not be specially considered for this kind of vessel in engineering design. But for brittle material of bad plasticity, the edge stress must be considered.

2. When welding seam at edge area has defects, inside stress of local material will remarkably go up. When there is a blowhole in welding bead, whose long axis is 2 mm and small axis is 1 mm, by calculation, tip stress of blowhole is as five times as that of no blowhole's tip.

The effective methods for reducing edge stress is provided in this article.