| 摘要 |
<p>During interior maintenance work on large vessels such as heat exchangers of nuclear reactors, the openings to supply and discharge ducts may be blocked by the use of this folding cover plate. It consists of a flat circular disc cut along a diameter into two parts (21, 22) and having a rectangular cut out in the middle, with its long edges parallel to the dividing diameter. Hinges (20) are provided at each end of the diameter, connecting the two halves together. The rectangular cut out provides an access hole which is covered by a removable door (23) fitted with longitudinal edge stiffening ribs and handles. Stiffening ribs on the cover plates are fitted parallel to the cut out edges and serve also as guides for centralising the door. A sealing membrane attached along the long edges of the cut out extends to cover the hole automatically when the plates are hinged out to seal the duct opening.</p> |
