Singapore - Trenchless International

CIPP
October 2010 - Trenchless International
28
the story behind the pipe:
an inside look at CIPP
By Dec Downey, Chairman ISTT
Cured-in-place-pipe (CIPP) has had an revolutionising effect on the world of
infrastructure and asset management. Here Trenchless International looks at the
history of the technology, how it was created, patented and its importance in the
trenchless industry.
accOrdING TO INduSTry legend, agricultural engineer Eric
Wood was repairing a corrosion hole in an air duct on a mushroom
farm when he conceived the concept behind CIPP – the use
of fluid pressure to press the repair medium against the pipe wall
whilst it cured in place to form a new pipe.
Whatever the truth of that story, the fact is that Mr Wood, ably
supported by entrepreneurs Doug Chick and Brain Chandler
started an industry with a far-reaching effect on the infrastructure
business, which has endured almost forty years.
Wood, Chick and Chandler took the concept, sourced materials
from resin producer scott Bader and felt maker WE Rawson
and developed what we know as Insituform. they took the idea
to the Greater London Council’s Metropolitan Water Board as a
means to restore ageing water mains and were given the opportunity
to demonstrate the efficacy of their method by lining a
The Brandenburger UV light curing in action.
100-year-old brick egg-shaped sewer at their own expense.
In 1971 they impregnated a felt tube with polyester resin,
wrapped in a plastic sheet, pulled the 70 m tube into the
1,175.675 mm Marsh Lane sewer, inflated it and left it to cure.
tested in 1991, after twenty years in service, it met the 4-34-04
flexural modulus requirements – a research-based group of WRc
– providing consultancy in the water, waste and environment
sectors in the UK – by a margin of more than 20 per cent. this
validated what many municipal engineers worldwide had already
concluded: CIPP is here to stay.
Wood, Chick and Chandler registered the company Insituform
Pipes and structures Ltd (the first of many vehicles for patents
and technology), and set about marketing their technology and
developing improvements such as polymer coated felt and
vacuum impregnation.
they tried steam and UV curing too, but concentrated efforts on
the time-proven water inversion and hot water cure system.
By 1986, with licensed partners in the United Kingdom, they
had completed over 400 projects for regional water authorities,
municipal boroughs, power generators and commercial companies.
As early as 1976 they lined pressure pipes, the first being a
600 mm force main for thames Water in Reading.
In the late 1970s they licensed various companies including
Entrepose in France, Olimb in Norway, Per Aarsleff in Denmark,
Monier in Australia and started a company in North America. With
no shortage of entrepreneurship for Eric, Doug and Brian, they
established Insituform North America Inc and Insituform Group
Ltd in Guernsey as a royalty collector.
these companies were floated on NAsDAQ, an American stock
exchange, and the proceeds invested in R&D and tube making
in Wellingborough and Memphis, tenessee. Both Insituform companies
began to acquire back licensee businesses to vertically
integrate and in 1991 merged to form Insituform technologies Inc.
Strong patent protection
this remarkable growth story was fostered by strong patent
protection and some remarkably good licensed partners. But the
protection afforded by patents is transient and long before the
expiry of the first layers of protection others had noted the extraordinary
growth of the business.
In Japan in 1980, the tokyo and Osaka Gas Companies,
with their contractors, developed hose lining systems using
woven polyester hose and epoxy and polyester resins. By
1983, PALtEM and Phoenix were well established and enhanced
with felt for extra stiffness became used in water mains and sewers.
Phoenix was licensed in France and switzerland and rapidly
spread through Europe. Also in France, in the early 1980s the
Copeflex process, a resin impregnated glass fibre liner developed
by Coopetanche and subsequently acquired by sADE made
inroads into the municipal sewer business.
In Germany, the sewer maintenance group Kanal Muller, once
sales agents for Insituform, developed and licensed a felt liner
system, InLiner, which is installed using a calibration hose, and
in sweden, Volmar Johnsson developed the glass fibre hose, UV
light cured InPipe system.
In the 1980s, with initial patents reaching maturity, many
developers looked at the lucrative licensing route for taking their
processes to market, and the multiple CIPP technologies spread
to the far corners of the globe – Korea, New Zealand, taiwan,
Venezuela and Argentina. Insituform, KMG and Ashimori, developers
of PALtEM, set up in unlicensed territories.
In the late 1980s, Insituform’s felt supplier WE Rawson established
Applied Felts to service the needs of the many users of the
basic felt and resin liner systems and other smaller felt liner makers
were established in Europe and America.
Prompted by the principles proven in the municipal market
and the success of products such as the KMG Houseliner, other
smaller contractors working with simple resin and felt systems
began to work in local markets, servicing the needs of householders
and other private sewer owners.
the size of this market is hard to quantify but some measure
of it is indicated by the UK Government’s decision to take about
half the private sewer, some 200,000 km, into public ownership.
In the UK, franchised sewer maintenance contractors groups
such as DynoRod have seized on the opportunity and provide
distribution for some of the smaller vendors who have focussed
on this market.
In the 1990s more UV light curing systems emerged in Europe
with first Brandenburger, then BKP Berolina, saertex Multiliner
and Impreg entering the fray.
their impact has perhaps been influenced by the technical
demands of the German market and the efforts of IKt, an independent
test laboratory in promoting its facilities and research
initiatives since about 2004. the annual performance tables of
IKt have caught the attention of owners and specifiers and now a
number of European contractors and municipalities are involved
in a pan European testing scheme which annually ranks the performance
of contractors.
confidence in cIPP
technical guidelines and standards play an important role in
the acceptance and growth of technologies, particularly in the
municipal infrastructure business. the role of WRc in developing
its Manual of sewer Condition Classification and its sewer
Rehabilitation Manual in 1983 cannot be understated. these
together with the WRc Information and Guidance Note (Water
Industry standard) 4-34-04 have influence the adoption of sewer
rehabilitation techniques in general, and CIPP in particular,
throughout the English-speaking world and beyond.
the WRc Approval, an independent view on performance
against accepted standards is also useful and many countries
have similar systems. the Japan Institute for Wastewater
Engineering technology is a particularly good example of a
systematic evaluation program in the public interest. Following on
from WIs 4-34-04 in 1985 came AtsM F1216 in 1979, EN 13566-4
in 2002 and now IsO 11296 in 2009; all serve to build confidence
in the CIPP concept but require that the utility owners and their
contractors implement proper systems for product acceptance,
quality control and assurance.
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CIPP
October 2010 - Trenchless International 29