Extracted text: A cylindrical pressure vessel of 2.5m inside diameter, which is closed at both ends, having 12 mm wall thickness operates at 1.5 MPa internal pressure. The plates are welded on a 30° helical spiral as shown in the figure. Detemine the stresses Oayluld acting normal and tangential to the weld. Consider the element A drawn below. 30 da = 2.5mm t= 12mm p=1.5MPA