ASSOCIATIONS
23
The development of trenchless technology to rehabilitate
existing underground infrastructure with minimal disruption to
surface traffic, business, and other activities, has left a lasting
impact on the construction and civil engineering industries.
By SAPPMA
As the name denotes, trenchless technology requires few or no trenches
to be dug for the maintenance work to be done and can be defined as,
“A family of methods, materials, and equipment capable of being used
for the installation of new or replacement or the rehabilitation of existing
underground infrastructure.”
Because trenchless technology greatly reduces the need for invasive
excavations, it has a much smaller impact on the surrounding environment,
both ecologically and socially. Residential neighbourhoods remain unscathed,
commercial districts do not have to deal with loss of business, and rural
regions remain undisturbed. Noise and air pollution are also kept to a
minimum and rehabilitation time is short.
“In the past, problems caused by aged and damaged sewer and stormwater
lines meant digging up and repairing or replacing each section of pipe that
needed attention. Completing repairs this way is labour-intensive and costly,
not to mention destructive to the surrounding landscape. Now, thanks to
modern pipeline trenchless rehabilitation technologies like HDPE pipe lining
repair and pipe bursting, we have a cost-effective and more sustainable way
to go about repairing pipelines,” says Jan Venter, CEO of the Southern African
Plastic Pipe Manufacturers Association (SAPPMA).
As the use of trenchless technology continues to grow in popularity and use, so
too does the importance of using top-quality pipe material that meets the specific
requirements of the particular technique being used. For this reason, a sound
working relationship exists between the Southern African Society of Trenchless
Technology (SASTT) and SAPPMA, whereby the one association focuses on the
installation techniques and the latter on the quality and type of materials used.
“The plastics pipe industry is a strategic industry, where hardware needs to be
reliable for extended periods of time. According to industry standards, quality
plastic pipe should endure in excess of 100 years without failure. For this
reason, SAPPMA’s vision is to ensure long-term product quality of the materials
used — whether it is in standard pipe installations or trenchless technology
applications,” Venter explains.
When it comes to trenchless technology, there are various methods to
choose from. The two most commonly used applications are:
• Pipe lining: This involves pulling or inverting a new liner into an
existing pipe, then applying heat and/or pressure to force the liner to
expand and fill the pipe.
• Pipe bursting: This involves fracturing a pipe from the inside and
forcing the fragments outwards while a new pipe is drawn in to replace
the old pipe.
www.plumbingafrica.co.za
Trenchless technology
important to SAPPMA
An example of inserting a pipe — the trenchless
technology way.
Most of the services that currently provide trenchless techniques are for
reticulation and collector systems of up to 450mm in diameter. These
installations involve the pulling, pushing, or expanding of pipes or pipe
components into place. Deteriorated pipelines are rehabilitated using various
types of slip lining and directional drilling, while existing pipelines can be
upsized using pipe bursting and its derivatives.
Thanks to the many benefits it presents in terms of cost-effectiveness,
minimised environmental impact, and safer procedures, using HDPE pipes
in trenchless technology is rapidly becoming the preferred method of
rehabilitating pipelines in the construction and civil engineering space. Not
only do these pipes offer a 100-year design life, but they also offer solutions to
major industry challenges such as corrosion and high leakage rates.
“HDPE pipes are ideal for pulling through long, underground holes as they
are flexible, robust, and resistant to almost all aggressive elements. These
plastic pipes offer a new generation of leak-proof, maintenance-free, and
energy-efficient pipeline systems that are chemical- and abrasion-resistant
and therefore excellent for use in the lining and relining of pipelines, slurry
applications, water reticulation, sewer and stormwater systems, the mining
industry, and in dolomite areas,” Venter explains.
Another prominent feature of HDPE pipe is the fact that it is available in a wide
variety of jointing systems to suit almost any application and installation method,
both new and existing. These pipes as can be welded into long continuous
lengths before being pulled into place and are available in diameters ranging from
16mm up to 1 000mm, and in pressure ranges from PN2.5 to PN25 in PE100.
“To ensure that the plastic pipes used in trenchless technology applications
are manufactured according to international quality standards, SAPPMA
has adopted the International Standards Organisation’s (ISO) standards for
setting the quality of thermoplastic (in particular HDPE and PVC) pipes, which
have been published as SANS/ISO standards. When we audit our member
companies, we ensure that their pipes meet these specified, stringent quality
standards before they are allowed to carry the SAPPMA mark of approval, in
addition to that of a product certification body such as South African Technical
Auditing Services (SATAS) or the SABS.
“We believe that by ensuring that contractors are supplied with piping
that meets the high-quality standards required for trenchless installations,
SAPPMA is playing an important role in supporting the country’s trenchless
industry,” Venter concludes. PA
For more information, visit www.sappma.co.za.
November 2018 Volume 24 I Number 9