Leak-free system
May 1st 2007 With a capability to produce 25
million magazines each week,
Polestar is the UK's largest
commercial printer. Operating for
24 hours a day, every day of the
year, its publications include the
majority of the Saturday and
Sunday newspaper colour
magazines and many of Britain's
largest shopping catalogues.
With its presses devouring a fivetonne
reel of newsprint in a little as
30 minutes, Polestar's state-of-theart
new printworks in Sheffield is
reliant on compressed air at
practically every stage of its
operation from driving ink into the
presses, to powering the machines
that bind and polythene bag the
finished product.
In what the company describes
as "the most obvious choice,"
Legris' Transair rapid-fit pipework
has been selected to carry these
vital air services throughout the
42,000 sq metre building.
Three separate Transair ring
mains in aluminium are connected
to the compressor in stainless steel
Transair and run for a length of three
kilometres, 70 feet high in the plant's
roof space. The pipework is colourcoded
for ease of recognition - blue
for compressed air, white for
vacuum and yellow for low pressure.
The 100 mm ring main drops to
a 1.5 kilometre sub ring main
comprising 63mm Transair
pipework at a lower level and then
to drops of 25mm Transair taking
the supply to point of use.
Such is the plant's requirement
for compressed air - for now and
for the future - that seven
compressors have been installed
on the site adjacent to the aircraft
hangar sized plant. The
compressors - six variable and one
fixed-speed - have a capacity of
more than 6,000cfm and feed a
10,000 litre receiver.
Two 100mm stainless steel
Transair lines for each of the
compressed air, vacuum and low
pressure services are used to link
the system from the compressor
site across a bridge and into the
plant's ring main.
Transair was selected as the
only pipework system able to meet
Polestar's three key criteria. It was
the only solution to meet the
stringent time constraints for
installation when the factory was
being built. It had to be energysaving
and leak-free in operation,
and it had to be easy to modify
after installation - particularly with
Polestar's expansion programme.
Anxious from the outset to avoid
traditional pipework that required
connections that had to be cut and
threaded or welded on site,
Polestar looked at another "rapidfit"
pipework system to compare
with Transair. With tube diameters
only as high as 60mm and far
lower flow rates, it was dismissed.
Another recommendation for
welded stainless steel was also
quickly rejected. It was heavier,
would have taken more time to
install, and offered no versatility in
allowing modification of the
system. In addition to lack of
colour co-ordination, it was also
more expensive.
Traditional galvanised steel was
also rejected at an early stage.
The equivalent size to Transair
made it a uncompetitive in terms of
both weight and installation time -
particularly working at the required
heights. Each length of pipework
would also have to be painted on
site, consuming even more labour
resources. Weekly tests on the
entire Transair system at Polestar
including ultrasound have found
it to be 100% leak free. More articles from Parker Legris Limited: | 
