Eight major leaks on the DN3000 Adduttore Sinni pipeline in southern Italy were repaired using purpose-designed Hydro Stop socket encapsulation collars.
Custom Hydro Stop collars were used to repair eight major leaks on one of southern Italy's most important large-diameter pipelines.
The Adduttore Sinni pipeline in southern Italy required repair of several significant leaks. The DN3000 pipeline carries fresh water to Apulia and Lucania and serves approximately 4.5 million people. It runs from the Sinni dam to the western area of the Taranto district over a distance of almost 133 km.
Pipeline leakage means not only the loss of treated water but also unnecessary electrical energy consumed in producing and pumping water that is subsequently lost.
Eight major leaks; eight custom collars
The ageing joints had developed multiple leaks, so a repair plan was required that would avoid interrupting supply on this critical transmission route. E.I.P.L.I. technicians identified eight major leakage points requiring special attention and requested an inspection to determine a specific solution for each location.
The DN3000 flanged connections and associated expansion joints had deteriorated and developed severe leakage. Given the large population that could have been affected by a supply interruption, Hydro Stop encapsulation collars were selected as the repair solution.
Eight different Hydro Stop collar configurations were designed for the eight leakage points. The collars were engineered to function both as repair clamps and as expansion-joint encapsulation solutions.
Challenging installation conditions
Seven days after the first pipeline inspection, the first Hydro Stop collar was installed at the location with the most serious leak. Additional collars were manufactured and installed over the following months to reduce water loss at the remaining locations.
Installation conditions were often demanding. The most challenging location was in the Montescaglioso district, where the pipeline crosses a hillside. Pressure at this location increased from a typical 10-16 bar to peaks of 24 bar, an exceptionally high pressure for a pipeline of this diameter. To provide the greatest possible long-term reliability, the collar dimensions were increased for this installation.
The largest collars installed at the time
E.I.P.L.I. management highlighted the flexibility and reliability of the solution. At the time of the project, these DN3000 socket encapsulation collars were the largest Hydro Stop units that had been installed.
About Hydro Stop encapsulation collars
Hydro Stop is a universal repair collar designed to encapsulate and seal leaks around the outside diameter of a pipe as well as leaking spigot/socket connections while the pipeline remains under pressure. The collar geometry can accommodate different connection arrangements, including joints between pipes made from different materials, flanged connections on steel pipes and remnants of previous repairs. The design can accommodate up to 40 mm tolerance in pipe outside diameter (OD), making it a practical solution when the exact OD cannot be measured, when the pipe is oval or when the pipe surface is damaged. The product range covers DN250-DN3000.
