The ductile iron pipe for drainage is connected to the wall of the inspection well, and the water stop ring is welded to the ductile iron pipe. When the reinforced concrete wall is constructed, it is directly poured in. This method uses the most materials, but the welding of ductile iron pipes requires a special welding process, so it must be welded in the factory and cannot be conventionally welded on site.
In addition, ductile iron pipes are conventionally T-shaped socket connections. Therefore, if rigid waterproof wing ring installation is adopted, the pipe must be installed first, and then according to the location of the pipe, the inspection well is finally poured. If the inspection wells at both ends are made first, and then the pipes are installed, the last section will fail to be connected.