| 摘要 |
<p>A service tee comprises a tubular T-piece (1) having a through-portion (2) with a flexible lower end (6) for connection to a gas or water main (70) by way of a hole in the wall of the main (70) and a side branch portion (3) for connection to a service pipe. The end (6) of the through-portion (2) is adapted for initial insertion into the hole in the wall of the main (70) and then for subsequent radial outward expansion so that its surface sealingly engages with the edge of the hole. An expander (4) is provided for location within the end (6) of the through-portion (2) and is adapted in a first position to permit initial insertion of the end of the through-portion (2) into the hole and on movement to a second position to cause expansion of the end (6) into engagement with the edge of the hole. A plug (5) is also provided, the plug (5) being engageable with the expander (4) and adapted to move the expander (4) from its first to its second position, the arrangement being that after expansion the plug (5) can be moved from a first position where the end (6) of the through-portion (2) is closed off from the side branch portion (3) to a second position where the side branch portion (3) and the end (6) of the through-portion (2) can communicate.</p> |
