| 摘要 |
<p>Starting with a piece of metal tubing, a hole is made in the wall where the lateral branch is to be made. The perforated tube is placed in a die which surrounds it, so that the hole in the tube coincides with the aperture in the die. Using two opposed plungers and a free spherical body, the edges of the hole in the tube are suitably deformed outwards. Finally, an additional tubular portion is welded on to form the T-joint.</p> |
