| 摘要 |
<p>A joint for a pipe fitting includes a socket 10 in a pipe 5, typically of PVC, and a corresponding spigot 12, with an insert 14 extending between a tapered section of pipe 5 and a free end of spigot 12, providing a substantially continuous internal surface of pipe 5, for example with spigot 12, insert 14 and pipe 5 having constant internal diameter. Insert 14 may be annular and frustoconical, and may seal between the tapered section and the free end, for example using snap clips (38, Figure 12). Alternatively, an insert (34, Figure 10) can be welded to spigot 12. A pipe socket forming mould (21, Figure 5) is provided comprising concentric first and second cylinders of different diameters (22, 23, Figure 5) with a radially extending shoulder (24, Figure 5) between them. Insert 14 can be affixed to a socket forming mould, which is inserted into and removed from pipe 5 to form socket 10 while retaining insert 14 in pipe 5. Insert 14 can suitably be formed from plastic, rubber or metal.</p> |
