Netphen

The “Wasserverband Siegen-Wittgenstein” is constructing a second 6.5 km long transport pipe from the Obernau reservoir to Dreis-Tiefenbach.
 
The pipe must reach up to 130 m in several inclines and falls on the way from the reservoir.
 
The reason for the second pipeline project was the construction of a bypass around the town of Netphen, which has been planned for over 20 years. This project also necessitated the redirection of the riverbed of the Sieg and a new course for the Weidenau-Deuz narrow-gauge railway. The required construction work also meant that the old transport pipe would have to be shut down for several days. The second pipe was therefore used as a substitute pipe.

One special feature:
2 km below the reservoir, the two transport pipes meet at a shaft construction, where the water coming down from the reservoir can be fed into one or the other pipe for onward transport as if at a set of railway points. The new cast iron pipe – from the reservoir to the shaft construction in DN 400 – runs on from here to the treatment plant 4.5 km lower down in DN 600.

Pipe material/Pipe connection
Pipes of ductile cast iron to DIN EN 545
Longitudinal positive-locking TYTON^®-NOVO-SIT^® socket connection

Pipe outer protection
Cement mortar coating (ZMU) to DIN 30 674, Part 2