| 摘要 |
<p>A pipe threading arrangement for connection to a service pipe (14) in a dwelling comprises a launch coupling (50) with a body portion (51) forming a chamber in which a parachute housing (60) is held. A stopper arrangement (30, 31) allows the coupling to be attached to the service pipe (14) whilst gas is present in both the service pipe and main. The housing includes a folded parachute-like device (62) attached to a line (66). A front portion of the parachute housing includes flexible guide (63) which allows the device to be manually lowered into a main pipe via the service pipe. A tube (65) is used to push the housing through the pipe. The tube is arranged to receive a jet of gas to separate the end with the guide attached and to inflate the parachute into the main where gas flow carries it along the main.</p> |
