Repairing critical DN3000 pipe leaks with encapsulation collars

To handle severe water losses, customised collars from Hydro Cos were used to repair eight major leaks on the largest pipeline in southern Italy.

Several leaks on the largest and most important pipeline in southern Italy, Adduttore Sinni, was in critical need of repair. The pipeline is DN3000, and supplies fresh water to Apulia and Lucania, serving about 4.5 million people. It goes from the Sinni dam to the western area of the Taranto district, covering a distance of about 133 kilometres.

Leaks on the pipeline means, of course, physical water losses, but also unnecessary energy consumption for producing and pumping clean water that is then finally lost.

Eight critical leaks; eight customised collars

There were many leaks on the old joints, so it was essential to plan the repair without causing any water stoppage on this important distribution line. In addition, E.I.P.L.I.’s technicians had identified eight critical leaks on the pipeline that needed particular attention and they asked us to perform inspections in order to provide a specific solution for each of them.

Basically, the DN3000 flanges that connected the pipes, as well as the expansion joints, were worn out and had started to leak severely. Considering the large population potentially involved in disruption of water supplies, the only possible way to perform any repair was by using our Hydro Stop socket encapsulation collars.

For the eight leaks, we designed eight different variants of Hydro Stop collars capable of working not only as encapsulation and repair collars, but also as expansion joints.

Challenging installation conditions

Seven days after the first inspection of the pipeline, the first Hydro Stop was installed on the location where the most severe leak had been detected. In the following months, the additional collars were manufactured and installed on the remaining leaks in order to reduce water losses.

During installation, we often had to face severe conditions: the most challenging installation was performed in the Montescaglioso district, where the pipeline crossed hillside. This special circumstance caused a pressure increase from an average of 10 to 16 bar up to a peak of 24 bar; a very high pressure for such an enormous pipeline! Stopping this leak was a real challenge, and we therefore decided to oversize the collar to ensure the highest possible reliability over time.

Largest collars installed to date

E.I.P.L.I. management was surprised by the flexibility and reliability of our product, and to date, these DN3000 collars are the largest socket encapsulating collars ever installed.

Details about Hydro Stop encapsulation collars

The Hydro Stop socket encapsulation collar is a universal repair collar designed to seal and encapsulate a leakage on the sleeve of a pipe as well as leaking or displaced spigot/socket joints - all while the pipeline is under pressure. The shaped carter can accommodate any type of pipe socket, including joints connecting two pipes of different materials, flange connections on steel pipes as well as remnants of any previous repairs. The collar features up to 40mm pipe OD tolerance, and is a good and safe solution even when the pipe OD has not been correctly detected, and in case of oval or in other ways damaged pipes. The product is available in DN250-3000.

Contact your local AVK supplier to learn more about the Hydro Stop range and your local possibilities.

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