| 摘要 |
<p>Metal tubes having an integral closed end (2), for example to contain a pyrometer thermocouple, are cast with a preformed silica tube (5) defining the central bore of the tube. The silica tube has a domed closed end (6) formed by fusing. Each metal tube (1) is cast in a vertical mould cavity with the upper open end of the silica tube (5) held in the upper end of the mould. A lower portion of the silica tube (5) is located in the mould cavity by a chaplet clip (17). The molten metal flows upwards in the cavity from the bottom thereof.</p> |
