| 摘要 |
<p>The edge of a cover is welded to the edge of a vessel by disposing a multi-section, separable welding tool therebetween so that substantially the entire vessel opening is uncovered. The edges are heated by the welding tool. Thereafter, the edges and tool are separated to allow the sections of the tool to be separated without passing across the vessel opening. Then the edges are joined together. The cover can include a depending lip which bears against an inside wall of the vessel during the heating, displacing and joining steps to maintain proper alignment between the cover and the vessel.</p> |
