In this year 2013 a new record was made in Lima, Peru. Polyethylene pipes DN/ID 3000 were used for a deep water outfall pipeline. The polyethylene pipes were produced according to the Krah-Technology in Spain by PPA&Krah, Vitoria. PPA&Krah had already a lot of successful installed large outfall pipelines in the Mediterranean Sea and Atlantic Ocean. One of the challenges in this Project was to open a new site for the Krah Large Pipe Technology – The Pacific Ocean.
The “Taboada” Wastewater Treatment Plant is one of the biggest constructions for sewage treatment all around the World.
The aim of the Project was to increase significantly the amount of treated water in the city of Lima, thus reducing ocean pollution and improving the health conditions in the area.
A Mega Waste Water Treatment Plant normally needs a large outfall to comply with the Project requirements. The dilution and hydraulic calculations were made and a pipe with an Internal Diameter of 3.000 mm was selected.
The Outfall is located in a seismic-sensitive region and it must be corrosion free.
It was decided by the end-user and main contractor to consider the Large Diameter helical structured polyethylene pipes (according to DIN16961) fabricated with Krah Technology and jointed by Electro fusion technology to meet the Project requirements.
Main Outfall features:
The pipes and fittings were manufactured and fabricated by PPA&Krah in Spain from where they were sent to Lima in 4 different shipments. Each pipe had a length of 6 m and the wall construction was not solid – it was a structured wall design, with the same or better characteristics than a solid wall pipe. Due the unique production process the pipes have no frozen stresses in the pipe wall and the profiled wall structure can be designed tailor made for the application requirements.
The helically wound pipes and fitting were welded by a patented Electro-Fusion welding procedure and they were ballasted on site before the launching of the sinking strings to the sea from the working ramp made onshore. All ballast blocks had no screws and bolts, by fixing them on special points of the special made pipes. So a later unwanted sliding of the blocks was impossible. And beside the technical aspects the costs compared to other solution was very low. (See foto TABOADA 4.JPG)
The construction of the sea outfall La Taboada was an amazing challenge for the PPA Group.
Up to 19 sinking strings were sunk and connected Off-shore. deepest point of the installation was -20 m in the Pacific Ocean.
Every string was joined by integrated flanges.
This challenge has been accomplished perfectly but now already several new ones in sight.
Pipe Producer: PPA&Krah, (www.ppakrah.com)
Installation was done by: PPA Peru.
Production Technology: Krah AG, Betzdorfer Str. 1, 57520 Schutzbach Germany, www.krah.net.