In What Shapes Can Forged Pressure Vessels be made?
Forged pressure vessels can be almost any shape, but shapes made of sections of spheres, cylinders, and cones are usually employed. A common design is a cylinder with endcaps called heads. Head shapes are most often round/circular or shaped like a dish. More complicated shapes have been more difficult to analyze for safe operation and are usually far more difficult to construct. That is why one-piece forged vessel components are FCI’s chosen product.
A spherical pressure vessel has approximately twice the strength of a cylindrical pressure vessel. However, a spherical shape is difficult to manufacture, and therefore more expensive, so most pressure vessels are cylindrical with 2:1 semi-elliptical heads or end caps on each end. Smaller pressure vessels are assembled from a pipe and two covers.
A disadvantage of these vessels is that greater breadths are more expensive. FCI is one of the only ASME pressure vessel forging companies that makes complete one-piece forged nozzles, forged vessel components and long weld neck flanges.