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CemPipe Ltd.
Creating a Middle Ground in Waterline Rehabilitation
By Nick Zubko
Before Thomas Edison invented the forerunner of the modern incandescent electric light
bulb in 1897, he spent almost 20 years experimenting with more than 6,000 different
filament materials. The concept of electric light had been tinkered with for more than 50
years — but it was Edison’s determination that finally brought it to the masses and
changed how people saw the world.
As a co-founder and director of CemPipe Ltd., Peter Wood is another firm-believer in the
empirical method of innovation. Even before he founded Plastech Alloys Ltd. in 1998,
Wood was committed to developing a cement-based product that could effectively line
and protect the pipes that bring us clean drinking water. After more than six years and
numerous trials, variations and trips back to the drawing board, his perseverance finally
paid off.
The product that resulted, dubbed “CemPipe,” is
quickly developing into one of the most promising
solutions for not only the repair, but also the safe,
long-term protection of potable water pipelines.
By combining the virtues of cement mortar and
polyethylene into one durable, functional liner,
CemPipe is setting the stage for what could be the
forward push that the water industry has needed
for quite some time.
“For several years I have been working to develop
a cheap lining system that would utilize cement —
not only because it is a proven material that has
been around for a decades, but because it
continuously prevents residual corrosion and can
provide a tremendous advantage over the resins
used today,” explains Wood, whose career in the
pipe lining and corrosion protection business
spans more than 30 years.
CemPipe Ltd. is quickly developing into one of the
most promising solutions for not only repair but
also the safe, long-term protection of potable water
pipelines.
Trial and Error
Since the beginning, Wood believed the answer to
lining water pipes lay in combining the benefits of
a cement mortar with a polymeric lining. The
theory was that this would overcome the water
quality issues associated with cement mortar,
which were caused primarily by alkalinity from the
cement mortars. Plus, the linings would eventually
erode away in acidic water.
“You have to ask yourself — if there’s a large
market out there for lining water mains, then why
hasn’t cured-in-place dominated,” questions Wood. “For one, it uses reactive resins that
are cured onsite. You can get NSF approval under ideal conditions, but onsite weather
conditions change curing properties, installation tension can vary or an overstretched
liner can become porous … anything can happen. So you really have no guarantee of a
thorough cure or a leak-free lining for your drinking water supplies.”
According to Wood, all the variables involved in cured-in-place prevent if from becoming
an economical option for the water industry. So when he started Plastech Alloys, the first
matter on the agenda was to explore how one could achieve a thin-walled lining using a

combination of cements, plastics and adhesives. As Wood came to find out, that feat was
easier said than done.
“I wanted to design a durable, ultra-thin liner and we believed the best route to achieve
that was cement and PE [polyethylene],” recalls Wood. “But the problem with
polyethylene, of course, is that you can’t really glue it to anything short of heating and
melting it because it’s a waxy type of material. So the best way to get a bond was to find
a PE material that could mechanically lock to the cement.”
While beginning his experimentation at Plastech Alloys, Wood was approached by the
U.K.’s Water Research Centre (WRc), which had filed for patents on a cement-based
cured-in-place felt material. The two combined efforts and attempted to incorporate the
patented technology into Wood’s work.
“We had a certain measure of success along that route — particularly by taking the felt
and making it castellated, or in other words like little ridges in the felt,” says Wood. “But
with the cement being so heavy, the tubes were difficult to handle and the polyester
fibers tended to filter water from the cement — which was very cumbersome.”
Plastech Alloys then approached Pipeway Ltd., a U.K.-based pipe lining contractor, which
at the time was owned by French water company Saur, to help develop the technology.
The incorporation of CemPipe Ltd. soon followed, along with a license agreement with
WRc. Over a four-year development period working with Pipeway (specifically Mike
Broadwood), the CemPipe product was taken through more than 50 incrementally
different incarnations.
“Like most things in the lining business, you have to develop the product empirically,”
says Wood. “You need to physically experiment and demonstrate it and measure its
performance to see how it works, but you can only accomplish that by trial and error —
you come up with something that you think will work, then you put it in and monitor it to
see where changes need to be made. You progressively change [the design], you don’t
just sit down with a pen and paper one afternoon, design it and say, ‘Well, there it is.’ It
doesn’t work that way.”
Primary design considerations included the method of tube manufacture, the design and
testing of installation fittings and a unique rounding device called a parachute pig. First
off, Wood wanted a leak-free tube. Second, to ensure that once a line was grouted, the
cement was distributed all the way around the pipe. After rigorous testing with different
locking mechanisms, CemPipe’s designers finally came up with the idea to give Velcro a
try.
Further investigation revealed that a Velcro product could in fact be produced with a
water industry-approved PE material. Incorporating a mechanical hook arrangement, the
polymeric layer could bond to the cement mortar and provide the correct depth of
cement mortar application within the pipe.
“In terms of development, incorporating the Velcro material was one of our biggest steps
forward,” Wood recalls. “Velcro used the same machine that it uses to make the
polypropylene hooks used for diapers. We wanted to make it out of polyethylene, which
Velcro was able to do for us, so that was a big achievement.”
Keeping It Simple
The top criteria for CemPipe was to develop a leak-free, gun-barrel liner that could repair
defects such as leaks in the host pipe, maintain water quality and provide active
corrosion protection. But even from the beginning, it was also critical to create a process
that was as simple and straightforward as possible.

The process involves insertion of a folded tube into
the main, which is manufactured in a flat form with
grout key hooks on one face. The tube is pulled
into the host pipe from an excavated point of
access with a device that folds the tube into a “C”
configuration. Once the tube has been fully
extended within the host main, installation fittings
are attached and cement mortar introduced.
The tube and cement mortar are rounded and
expanded under pressure, forcing some of the
cement mortar into any existing holes or gaps
created by misplaced joints, and — in the case of
bell and spigot joints — the sealing of these joints
where joint packing fails. Pressure is applied to a
Peter Wood, co-founder and director CemPipe Ltd. (center),
is committed to bringing his product to new markets. Here, he
is talking up his product at the recent Hamburg No-Dig show.
parachute pig as it moves down the pipe, expanding as the cement mortar fills any voids
around the grout key hooks. Pressure is maintained by holding the tube and the cement
mortar against the host main until the cement hydrates. After approximately 16 hours,
return to service procedures can be carried out and the services reconnected.
“A unique thing about CemPipe is that it’s so damn simple,” Wood explains. “People look
at it and think that it’s too simple to even work, but it took a long time and a lot of effort
to develop the simplicity into the process that we have now. And based on my
experience, contractors have found it expensive to get into the lining business because of
the money spent on special equipment. So we also wanted to keep the technology simple
to minimize the cost of special equipment.”
CemPipe is ideal for countries where the use of local labor
is encouraged because installation training is quick.
The system was also designed to be as contractorfriendly
as possible. The CemPipe system requires
low capital expenditure on specialty equipment, a
small site footprint and low bulk storage
requirements — contractors can transport more
than 300 m of tube in the trunk of a car and all of
the installation equipment fits onto a small pickup.
The cement used is available worldwide and is
cheap, making it ideal for use in developing and
third world countries where the use of local labor is
an advantage to the client.
“CemPipe is ideal for use in those countries where
the use of local labor is encouraged,” Wood points
out. “Installation training is quick and the skills
required to install linings can be taught to unskilled
workers. Given that a client in a developing
country needs to rehabilitate his pressure mains,
he could utilize the local labor without the need for
a high expatriate contingent — thereby creating
new jobs in the community.”
Developing Markets
The CemPipe liner has been in its current form for
the last 18 months, integrated into water systems
in the United Kingdom, Western Europe and in Russia. The product has met every safety
standard for which it has been submitted, including approval under the U.K. Reg (1) (a)
and BS6920 and Authorized Registered Formulation (ARF) status in the United States as
of January 2001. The rapid progress led CemPipe Ltd. to buy out its partnership with
Pipeway in September 2004, and has since opened tube production facilities in the
Netherlands and offices in the United Kingdom and Germany.
In late 2003, Pipeway, which remains a CemPipe licensee, installed CemPipe in three
drinking water lines as part of a main rehabilitation program for the U.K.’s South East

Water, which supplies 1.5 million people in southeast England with more than 400 million
liters of drinking water a day.
“Since we put those three sections in, we’ve had no burst mains in those areas, no
failures at all, which is brilliant,” says Dave Skelhorne, South East Water’s general
manager. “Another advantage of the CemPipe is cost. With normal rehabilitation, we put
a 50-year life on the actual lining but we don’t put any extra life on the main. With
CemPipe, you extend the life of the main as well, which saves you money for a longer
period of time.”
CemPipe has already expanded its list of licensees into Portugal, Hong Kong, Germany
and Russia, with more negotiations in progress that are likely to be concluded during the
first quarter of 2005. As far as North America is concerned, CemPipe is currently
investigating how to take advantage of this potentially large market. The company has
already registered a separate U.S.-based company called Mainsaver Inc., in Delaware —
serving as a prelude to its entry into the North American market. Their game plan has
yet to be finalized, but Wood says it’s going to happen in the near future.
“We’ve already developed markets in the U.K., Eastern Europe, China, but it’s the U.S.
market where everyone is waiting for something to happen,” Wood says. “It’s not a big
drinking water lining market at the moment — in terms of expenditure on water pipeline
renovation. But with all the attention that drinking water has been getting, I think it’s
ready to open up and become a lucrative market.
“People don’t buy sewage, but they buy drinking water. And since it’s a salable
commodity you have to deliver it to the customer in the right condition, at the right
pressure and the right price. And that’s what we’re trying to do with CemPipe.”
Nick Zubko is associate editor of Trenchless Technology