| 摘要 |
<p>The jig is inserted in the bore of the two pipes (3,4) being butt welded, and consists of a stationary shaft (6) fitted with circular rows of clamping plungers (19) which are driven radially outwards to clamp shaft (6) in the bore of one pipe (3). Shaft (6) also carries an expandable or inflatable ring seal forced against the bore of pipe (3) near the butt joint (3,4) to make a vacuum-tight seal. On shaft (6) is a sliding tube (2) with a flange carrying a second inflatable seal (8) forced against the bore of pipe (4) to make a vacuum tight seal. Air is thus prevented from reaching the bore of the butt joint being welded. Used for e.g. in the rapid, electron-beam butt welding of thick-walled pipes.</p> |
