July 2014 Tube Products International
49
Inspect ion and corrosion protect ion
Corrosion protection of
coated carbon steel pipes
Steel water pipes have been the choice
for many pipeline sites across the UK.
Some of the benefits associated with
steel include pressure ratings, no
thrust blocks, longer lengths, flexibility,
variety of end connections, and epoxy
or cement mortar internal linings.
However, the over-riding benefit to the
water industry of steel pipes supplied by
FT Pipeline Systems lies in the corrosion
protection provided by the three-layer
blue polyethylene according to DIN
30670.
Pipe and fitting surfaces are prepared
by blasting and heating prior to the
application of fusion bonded epoxy
(to 150 microns), adhesive (to 100
microns), and extruded, heat-bonded
polyethylene.
The properties of the three-layer coating
are based on the adhesion between the
layers. This provides protection from
impact and indentation, as well as
corrosion protection.
FT Pipeline Systems supplied pipes
and pipe fittings to a variety of different
projects in preparation for the London
Olympics in 2012. Steel was chosen
over alternative materials by a number
of contractors due to the difficult
ground issues prevalent in the East
London area.
Ranging from 80 to 1,200mm diameter,
all the pipes and fittings supplied
complied with DWI regulations and
were coated with the three-layer
PE, allowing them to be installed in
brownfield sites. Projects included
the infrastructure of the Olympic Park
in Stratford, East London, the water
mains replacement at Finsbury Park,
and the provision of the white water
canoe centre.
The company recommends protecting
pipe joints with its range of Canusa
heat shrink sleeves. The heat activated/
PE wraps for corrosion protection of all
types of jointing method are quick to
install, as there is no need to prime or
profile the pipe.
Carbon steel pipeline installations
can also be cathodically protected
if low resistivity soils are present.
Welded steel pipes, being electrically
connected, are very simply and
cheaply protected by sacrificial anode
or other cathodic protection systems.
Once in the ground, a coated carbon
steel water pipeline will provide an
extended service life. Combined with
cathodic protection, the water utility
has a secure, well-protected asset. FT
Pipeline Systems offers a complete
range of steel water pipes and fittings
in an extensive range of diameters
and joint types, along with field joint
protection sleeves.
FT Pipeline Systems Ltd
– UK
DIN 30670 three-layer polyethylene application
Coating performance inside and out
PPG Protective and Marine Coatings
has completed a major project for Africa
Pipe Industries, supplying internal and
external coatings on a 46km, 2.1m
diameter pipeline installed for South
African utility Rand Water.
PPG supplied Sigmaline 523 as an
internal lining and Sigmaline 855 as an
external coating on the pipe installed
at Sasolburg in the Free State region.
Together, the coatings deliver high
performance protection of both surfaces
against corrosion and contamination of
the pipeline content.
The continued demand for resource
infrastructure in South Africa has seen
Africa Pipe Industries play a significant
role in the roll-out of new bulk water
services in South Africa as well as
providing oil and gas piping. PPG has
built up more than 60 years’ experience
and continuous investment in Africa,
demonstrating a long-term commitment
to customers across the continent.
Marius Rademeyer, market manager,
PPG Protective and Marine Coatings,
said, “This project required PPG to
provide corrosion and bacterial
protection to international standards
and very specific customer demands.
Sigmaline products have short
manufacturing cycles due to quick
curing times and the key advantage of
single coat application properties.”
For the pipeline’s external coating,
Sigmaline 855 offers corrosion and
water resistance and an aesthetic finish.
The coating’s abrasion and impact
resistance protected against minor
damage during handling, transporting
and installation, with UV protection
while awaiting installation on-site.
PPG Protective and Marine Coatings
– USA
Coated pipes
