Vilniaus šilumos tinklai, a company operating the city district heating system in Vilnius, Lithuania, faced a challenge: a DN 500 pipe system embedded in a concrete bridge structure needed renovation. This heavily used bridge contained six traffic lanes, including several electrical trolleybus lines and sidewalks for pedestrians and cyclists. It spanned a 10-track railway yard heading in and out from the city’s central station.The pipes were built into the bridge structure, due to which legislation banned all interventions of the bridge while it was in use. Therefore, if the pipe system had been renewed using traditional replacement methods, city traffic would have been severely affected, and complex and costly alternative rerouting options would have been needed.

Rehabilitation of the pipe system was carried out using CarboSeal DN 500 in September 2022. The liner was introduced to the pipes though a four metre deep chamber with a manhole entrance from the sidewalk. The sidewalk was slightly narrowed down but kept continuously open for pedestriansand cyclists. The vehicle lanes were completely unaffected during the installation.

The installation of CarboSeal took two days, and the entire operation took five days. The Lithuanian company Poli conducted the installation with the help of PPR personnel on-site.