Why have a “dished head” on a wire seal flange?
A dished head provides a blank flange without the significant weight that a solid blank flange would have. The dished head is usually 3/16-inch thick, whereas a solid blank ranges from 1.125- to 1.750-inch thick. Although the primary savings is in weight, a comparison of prices shows the dished head blank to be less expensive than the solid flat blank. The curved surface of the dished head absorbs the pressure of the atmosphere without deformation. In a similar manner, a cylindrical vacuum chamber can be constructed with walls that are much thinner than a rectangular chamber. Again, the savings are in a significant weight reduction.
