A DN1000 drinking water siphon operating at 6 bar pressure beneath the Danube River required structural rehabilitation without intermediate access shafts.
The project demanded a fully structural trenchless solution capable of handling large diameter, high internal pressure, and complex installation conditions below a major river crossing.
| Medium | Diameter | Project Length | Pipe Conditions | Rehabilitation Method |
| Drinking water | DN 1000 (39.4") | 260 meters (853 feet) | DN1000 pressurized drinking water siphon beneath the Danube River, inaccessible mid-span, partially water-filled, and operating under 6 bar internal pressure. | NORDIFLOW W |
Technology: CIPP (Cured-In-Place Pipe)
Product: NORDIFLOW W
DN1000 drinking water pressure pipeline operating at 6 bar
Siphon located beneath the Danube River, with no possibility of intermediate access
Entire 200 m river crossing required a single continuous installation
Glass-reinforced felt liner with 23.7 kg/m self-weight
Approx. 12 tons of resin impregnated on site, total liner weight >16.7 tons
Handling, impregnation, and installation of an extremely heavy liner
Precise vacuum impregnation and cooling required to prevent premature curing
Siphon could not be fully drained, requiring strict separation of resin and wate
Successful trenchless rehabilitation of a DN1000 drinking water siphon
River crossing completed without intermediate access shafts
Installation performed without fully draining the pipeline
Resin effectively protected from contact with water
Liner passed CCTV inspection and pressure testing
Proven suitability of NORDIFLOW Class A liners for large-diameter, high-pressure river crossings
