Weir wear repair
May 1st 2010 When it came to repairing Parteen weir hydroelectric power station, Loctite's Nordbak products
were able not only to do the job but to provide high wear resistance for the future
ESB Energy International is a semi state
power producer in The Republic of
Ireland. Among its many facilities is
the important Ardnacrusha hydroelectric
power station, located at Parteen Weir,
County Clare. Completed in 1929, this
became a benchmark for large scale
hydroelectric schemes in many other
locations around the world.
Today, the station provides power supplies
for the adjoining counties of Clare, Tipperary
and Limerick as well as to the national grid.
Coping with large amounts of fast flowing
water can be a challenge, so when the
protective coating of the mini hydro turbine
casing needed replacing it was necessary to
find a method that would withstand the
considerable battering that was part of the
testing environment.
"The materials involve Stainless Steel plates
with a Cast Iron casing,"
reports Pat Hogan,
Maintenance Supervisor at the
plant. "We had looked at
welding, but this could have
produced failures when the
metallurgy considerations are
taken into account."
On the advice of the local
Henkel sales engineer, Pat
tried Loctite Nordbak 7222
and 7227 for the task. These are
wearing compounds that combine the wellestablished
wear properties of ceramic with
the convenience and durability of two-part
epoxies in order to protect equipment from
corrosion, erosion, abrasion, chemicals and
other potentially damaging conditions
encountered in harsh environments.
The underlying purpose behind each
compound is to help save costs by extending
equipment life.
Loctite Nordbak 7222 Wear Resistant Putty
is a ceramic based, non-rusting trowelable
product that cures to a smooth, low friction
finish.
Loctite Nordbak 7227 is a grey ultrasmooth
ceramic reinforced epoxy that
provides a high gloss, low friction coating to
provide protection against turbulence,
abrasion and cavitations.
In this application, where the leading edge
of the cast iron casing was worn by excessive
cavitations, the lost metal was replaced with a
formed Stainless Steel replacement ring and
is then re-profiled using Loctite 7222. The
procedure was completed with a finish coat
of 7227 to produce the wear resistance and to
improve fluid flow. In turn, these finishes
will produce better turbine efficiency.
"We are anticipating that this will be a cost
effective repair that will result in reduced
downtime, and longer service life for hydro
turbine," concludes Pat. More articles from Henkel Ltd: | 
