Rehabilitation of a Double, Gravity Potable Water Line in Budapest with CC-GRP HOBAS Pipes and HOBAS NC Profiles 1500/1500 mm
Hungary’s capital Budapest is located on the Danube and has almost 2 million inhabitants. To secure the supply of clean and healthy potable water, some of the more than one hundred years old pipelines were relined and renewed with circular HOBAS CC-GRP Pipes.
The old non-circular 1500/1500 mm concrete pipeline was built at the end of the 19th century. It showed typical damages such as corrosion, encrustations, and small cracks, which had developed over its longterm use and made a renewal of the pipeline necessary.
The client looked for a pipe material with a smooth inner surface, good hydraulic properties, and abrasion resistance. A long lifetime and therefore good quality were further criteria. Another requirement was chemical resistance, since the city of Budapest uses chlorine to clean its potable water lines. Static calculations showed that pipes with a low wall thickness (SN 2500) could be used in this area, as there is no traffic load and the pipeline is covered with an average of 1.5 m of soil.
The installation was split into three periods. In summer, when the water consumption is high, it was impossible to work on the pipeline. Installation could only take place in spring, late autumn, and winter. As HOBAS Pipes can be installed in all weather conditions, this was another reason for the constructor to choose HOBAS CC-GRP Pipes.
The old line was opened every 300 m and the pipes were installed from there. Also the manholes were relined with HOBAS Pipes DN 900. The gap between the old and new pipe was grouted with a special cement. Because of the low weight and easy installation of HOBAS CC-GRP Pipes, only 3 to 4 workers had to work on the construction site. Two of them relined the pipe by pushing the HOBAS Pipe into the old channel using special equipment with wheels. One person navigated the excavator, lifted and put the pipes into the right place, and another person assisted where necessary. Thanks to this small number of workmen the construction costs could be kept at a minimum.