In order to connect the double-walled pipes, like connecting single-walled ones, after adjusting the height of the pipe and its distance from the base of the manhole, we find the exact place of the connection of the pipe to the manhole and then, we make a hole in 1 diameter more on cm on the wall of the polyethylene manhole using a hole saw or a saw, and completely finish the area around the hole.

We do the cutting and after installing the waterproofing O-Ring, we connect the coupler to the polyethylene manhole.

 

After connecting the coupler to the polyethylene manhole, we put and stabilize it in its place and then, we connect the double-walled pipe to the coupler.