Articles & Case Studies
BorSafe™ HE3490-LS delivers longevity to Estonian
Posted: Thursday 1st March 2012
Durability and efficiency were the determining factors behind the choice of
PE100 BorSafe™ HE3490-LS from Borealis, a leading provider of
chemical and innovative plastics solutions, for renovation of a crucial
cooling water circulation system at the world’s two biggest oil shale-fired
thermal power plants.
Estonian Energy, referred to locally as “Eesti Energia,” owns and operates
the large production facilities at Narva, close to Estonia’s northeast border
with Russia. The Narva thermal power plants have a power generating
capacity in excess of 2,300MW. Estonia Energy is the leading electrical
energy producer in Estonia, one of the largest providers in the Baltic region
and an exporter of electricity to the Nordic power market.
Upon discovering extensive pipe corrosion in the system as part of an
ongoing improvement programme at Narva, Estonia Energy turned to
independent Estonia-based specialist plastic pipe producer Krah Pipes OÛ
to upgrade the approximately 40-year-old steel cooling water pipes. The
old pipes did not have a Borealis coating and were not made of Borealis
material. Key requirements for the new network, involving two parallel
pipelines running from a pumping station to the plants’ turbine room, were
safety and the reduced maintenance of leak-free pipes with a minimum 30-
year service life. Speed and flexibility of installation were particularly
important to avoid significant power generating downtime and major cost
penalties.
Borealis’ bimodal HDPE BorSafe HE3490-LS was identified as the pipe
material offering the optimum balance of properties to meet the project’s
criteria. The high performance PE100 material, classified MRS 10 and on
the positive list of the PE100+ Association, exceeds the reference standard
for the production of these pipes. It has become the reference material for
many industrial pipe and pipe relining projects globally.
BorSafe HE3490-LS offers a wide range of advanced properties including
low notch sensitivity. Three installation techniques - open trench, relining,
and prefabricated segments for horizontal and vertical bends - were
required at Narva because of the complexity of the system, which includes
a 30m section beneath a concrete platform supporting 120 tonne
transformers. Here electro-fusion welded pipes were pulled through and
positioned in the pre-existing metal pipeline.
The consistent quality of BorSafe HE3490-LS allows for easy processing of
both straight pipe sections and bends. The PE100 material creates smooth
inner pipe surfaces and therefore a lower roughness coefficient than metal.
As a result, Krah Pipes was able to produce spiral wound pipes with a
reduced inside diameter of 1400mm, compared to the 1580mm of the
previous steel pipes whilst maintaining the same flow. A wall thickness of
20mm was used to deliver the necessary ring stiffness to ensure pipe
integrity at the weld lines.
The Estonian Energy Narva plant pipe system renovation project
commenced in September 2010 and was completed, system-tested and
reactivated in November 2010.
“Choosing a material such as BorSafe HE3490-LS with a long track record
was essential for the success of the project,” comments Peeter Kirtsi, CEO
of Krah Pipes OÜ. “Also, the very good processability of the product
contributed to the trouble-free production of the pipes.”
“This successful application of BorSafe HE3490-LS clearly demonstrates
how Borealis’ innovation is able to bring value-added benefits to the entire
chain: trouble-free production for Krah Pipes OÛ and excellent end-user
performance for Estonian Energy,” adds Jane Toogood, Borealis Vice
President Business Unit Pipe. “Such an example is built on our longstanding
leadership and dedication to the industry.”
