A pressure pipeline in diameter 1000 mm,
10 bar in Cartagena / Columbia
August 2009. Isabella Di Cagno of Krah AG who has developed the KPPS System visited Cartagena
Columbia to see KPPS-pressure pipeline, the first installation in Latin America of this kind of pipe system.
Picture: Welded KPPS Pipes
She met and talked to Antonio Núñez the General Manager of Krah Chile who are the producer and supplier
of the installed pipes.
Mr. Antonio Núñez, Krah Chile
1|p a g e
Mr Robledo - General Manager of Aguas Cartagena (final client of the pipes)
The used material PE-GF180 which is consisting of 78% polyethylene, 20 % fibre glass and 2 % bonding
agent.
PE 78%
Fibre 20%
Bonding agent 2%
The MRS-Value is MRS=18 N/mm² (PE80 = 8N/mm² and with PE100 = 10 N/mm²) – which results in
significant reduction of the wall thickness. The complete pipe system was produced with the KDR700
machine which is in operation since April 2009 at the Company Krah Chile, located in Santiago. This
machine is able to produce pipes for pressure and low pressure pipe applications in diameters up to 3000
mm.
Picture: Production line in Chile
2|p a g e
To reasons and advantages why this pipe system has been chosen were explained by Mr Robledo and Mr
Núñez as follows:
Why did you decide to use Krah pipes?
Mr Robledo: The price and feasibility to connect pipes with this extra ordinary welding technology
and the resulting homogeneous pipe system have been a crucial factor. Of course also to install
modern materials with life time over 100 years was a great advantage compared to old-fashioned
pipe systems.
Which where the geological conditions? How were the requirements or the ground conditions in this
installation?
Mr Robledo: A very important aspect currently here in Cartagena is that the ground is very salty
(acidic PH<7), which causes a fast corrosion with standard pipe systems. The robustness and
flexibility of this pipeline allowes a quick and simple laying and installation.
Which Pipe systems did you use in the past?
Mr Robledo: Especially in big diameter ranges: Ductile Iron, Carbon Steel and GRP were used. In
small diameter ranges we already have a lot experience with Polyethylene and PVC pipe systems.
Why didn’t you choose normal PE-pipes?
Mr Núñez: The key benefit for the pipe application is the technical feasibility to reduce the wall
thickness of the pipeline. – Competitive prices in spite of high transportation costs and very good
stability against ovality, despite constant ambient temperature of 35°C a great advantages of the
KPPS system.
Picture: Pipe transportation in a 40“ Container
3|p a g e
How works the welding?
Mr Núñez: As you can see, very good. We are able to jointed every day six pipes ( in total 36 m)
together with the help of butt-welding. For this purpose we use a manual butt – welding machine
produced WIDOS (Type: 1200). We have sent an employee from Chile to Cartagena to train the local
personell and also to control the welding.
Picture: Butt - welding of 1000 mm, 10 bar
Why are the pipes not being welded inside the trench?
Mr Núñez: It is not possible to carry out the jointing in the trench because the complete welding
device would also have to be placed inside the trench because there is no space enough. Therefore
we connect the whole line outside on the temporary street and install it as on piece after the welding
is done.
Picture: Installation in the trench
4|p a g e
Would the intergrated Electro fusion welding technology, recommended by Krah AG, not be a good
alternative?
Mr Núñez: Yes, we are trying to use this technology in the next segment, which will reduce the
installation time considerably. We expect that according to our calculation we will be able to make
ten weldings per day inside the trench, which is a great advantage. The trench can be refilled
immediately and the whole construction process can be shortened.
Did you need fittings as well?
Mr Núñez: Yes, one T-piece 1000/600/1000, segmented from different pipes and a reduction out of
stainless steel will be flange connected. This part will be used for later for monitoring and control.
Picture: Fitting
There were no elbows necessary?
No. Because of the flexibility of the pipe system all curves could be realized during installation
without elbows up to R/D=40.
Do you see any other advantages of the KPPS pipe systems beside the welding connection and reduced
wall thicknesses?
Mr Núñez: Yes, of course. For example: there is no or only minimum axial extension during
temperature fluctuation. Especially in the north of Chile temperature fluctuations up to 40°C per day
are reality. You are very welcome to visit us in Chile in order to gain an own empression.
5|p a g e
Picture: Ms. Isabella di Cagno – Krah AG/Germany; Mr. Antonio Nuñez – Krah Chile/Chile
Project facts:
Application:
Raw Water, Transportation from Rio Magdalena to central distribution point
of Aguas de Cartagena
Diameter:
1000 mm DN/ID
Working Pressure:
10 bar
Test Pressure:
15 bar
Material:
PE-GF180, according to ISO 2…
Total length:
7 km (first segment 1 km)
Fittings:
One T-piece 1000mm/600mm/1000mm
Jointing technology:
Butt-Welding, done by WIDOS 1200
Client:
Aqua de Cartagena (part of Agua de Barcelona, Spain)
Pipe Producer:
Krah Chile, Santiago de Chile
6|p a g e