| 摘要 |
A steel service pipe is connected to a main by a tee. A flexible assembly is inserted through the open end of the pipe and through the tee into the main. The flexible assembly includes a section of lower stiffness and a ball and socket connection of even lower stiffness at its leading end. The ball is connected to a weight. The weight falls down on entering the tee and creates a turning moment on the assembly. A plastic pipe is inserted through the open end of the pipe over the assembly and is inserted through the tee into the main. The pipe has a corrugated leading end which is more flexible than the remainder of the pipe and has a tapered nose terminating in a cylindrical mouth which enters an aperture in a liner in the main. |
