May 2013 Tube Products International
9
business & market news
New lease of life for pipeline
GPS PE Pipe Systems has supplied over
36km of PE piping for the refurbishment
of a 130-year-old large diameter trunk
main as part of United Utilities £3.6bn
investment programme for the North
West of England.
Carrying 210mn litres of water a day
to 900,000 people in Cheshire and
Merseyside, the trunk main consists of
three parallel pipelines that run fromLake
Vyrnwy in Powys, through Oswestry
Water Treatment Works to Prescot Water
Treatment Works near Liverpool. Lines 1
and 2 were constructed as unlined cast
iron mains in the 1890s, while Line 3 is a
bitumen-lined steel main that was laid in
the 1930s and 40s. Iron and manganese
deposits in the water supplied from
Oswestry WTW and the risk of internal
corrosion in the unlined cast iron mains
have prompted the refurbishment to
avoid the possibility of discoloured
water due to iron deposits.
The refurbishment scheme has already
seen main contractor Balfour Beatty
clean around 44km of Line 3 using
specialist high pressure jets and line
the section of Lines 1 and 2 that run
between Oswestry WTW and New
Crickett.
For phase two of the programme, the
contractor will draw down (reduce
diameter) 1,030mm diameter Excel New
Blue in SDR51 supplied by GPS to line
the Crickett to Malpas sections of Lines
1 and 2, creating a tight-fitting, thin
walled internal lining for the pipelines
that will prevent iron from entering the
supply during transit without excessively
reducing capacity in the trunk mains.
To carry out the lining operation the
contractor will pull a pre-welded string
of PE pipe through a reducing die, which
will temporarily reduce the diameter of
the PE pipe allowing it to be inserted
into the existing pipeline in a single
operation. Once the insertion pulling
force has been removed, the pipe will
begin to revert back to
its original size until it fits
tightly against the wall of
the host pipe. GPS has
supplied the piping in
13.5m lengths to reduce
the number of joints
required to create the
PE string for insertion.
Nick Preston fromUnited
Utilities commented,
“PE pipe provides an
ideal solution for lining
operations such as
this as it offers such
flexibility and can be
used in a large diameter
with a thin wall without
compromising on pipe
integrity or capacity.
This major improvement
to the main not only
maximises the service
life of the existing
pipeline asset but also
safeguards the quality
of water supply with
minimum environmental
impact.”
Phase 2 of the refurbishment programme
is expected to be completed in 2015,
and will be followed by a third and final
phase to clean and refurbish Lines 1
and 2 between Malpas and Prescot
WTW along with Line 3 between Malpas
and Norton Tower.
GPS PE Pipe Systems
– UK
Guide to welding positions, electrodes
and standards
A free guide to ASME IX/ BS EN
ISO 6947 welding positions is now
available from ESAB.
As well as showing all the different
positions, the guide provides
information on the recommended
ESAB electrodes when welding
mild steel across a range of
applications.
The simple guide is clearly illustrated
to show basic welding positions and
the correct ASME/BS EN ISO 6947
code, such as 2G/PC for horizontal/
vertical welding.
It is suitable for those involved in
welding as part of a production
engineering department, in fabrication
work, design, welder training or welding
inspection within a quality control
regime. The guide also explains the
latest British/European MMA welding
electrode standards, as a number of
these have been re-designated into
new BS EN ISO Standards.
ESAB
– UK
GPS supplied PE piping for the large diameter trunk
main refurbishment
