Situation
Network operator Quang Ninh Water Company (QUAWACO) is operating a DN 300 steel water main located underneath and inside a bridge construction to supply Van Don Island. The three individual bridges have a length of 410 m, 170 m and 270 m, and the pipes were originally installed in 2002 at the same time when the bridge was constructed. Because of corrosion and in order to secure the water quality, the network operator decided to perform preventative maintenance on these steel pipes. The goal of the renovation works was to elongate their life span and secure the water supply.