Hemispherical Heads have a radial geometry, where the head depth is half the diameter. These storage heads consist of two pressure heads that are placed against each other – back to back. This helps to create a storage looking sphere, which stores with ease materials at high pressure consistency. Hemispherical heads consist of thinner heads than shells and use a standard code 3:1 that taper during the changeover. In most cases, hemispherical heads are constructed using welded sheets rather than flat sheets which are predominantly used in other head types. Therefore making the hemispherical heads the thinnest head, as well as one of the most costly types. These heads are favored for applications that require large diameter vessels or high-pressure storage.