A segmented plate adapted for assembly within a confined area or volume, and a method of assembly of the segmented plate. The plate, as assembled, has an exterior perimeter that includes exterior edge-boundaries of a plurality of generally rigid plate-sections, each of the plate-sections are sized smaller than the access to permit passage therethrough. Extending at least partially along adjacent boundaries of plate-sections that have been adjacently arranged, is a self-lock seam, or interposed therebetween is a flexible barrier. The self-lock seam may have a variety of configurations. An aperture or opening having an inner perimeter may be included. The inner perimeter of the aperture/opening may be of a variety of shapes. The confined area may consist of a chamber of a deaerator tank or other volume to which access is limited. The flexible barrier may be made of a material having resiliency.