Overview

Trenchless Pipe Replacement

RePipe is an Australian company established to replace underground pipes with minimal disruption. Indeed, RePipe’s service goal is to ensure “Our clients don’t notice us”. RePipe minimises disruption by delivering 2 interdependent solutions – exclusive trenchless technologies combined with advanced risk management systems.

RePipe’s exclusive trenchless technologies provide the least invasive way of replacing underground pipes with a brand new pipe of equivalent or larger diameter. On average, RePipe’s technologies require only 10% of the excavation associated with open-trenching. By minimising excavation, RePipe substantially reduces the risk, inconvenience, disruption, environmental impact and cost of replacing underground pipes.

Importantly, RePipe’s exclusive trenchless technologies can replace almost all types and sizes of underground pipes – from large diameter mains and industrial pipes to small diameter residential pipes – and RePipe has customised solutions for all underground pipe owners – from governments, utilities and industry to landlords and homeowners.


I just wanted to send you a quick letter to say how happy we are with the job you have done.

I spoke to our tenant today who was very pleased with the way in which your team conducted themselves whilst on the property. She could not have spoken more highly of the level of professionalism that was displayed, and also on how exact the place was put back to its original form. The manners and consideration shown to the tenants was very much appreciated. As you can understand, as a landlord, this is very important to us that the tenant was well looked after and the inconvenience to them kept to a minimum.

From mine and Todd’s perspective we would have to agree with the tenant. Your company has been a refreshing change to the level of quality (or lack of) that we have been used to. You have kept us informed constantly with your operations, you have made promises and kept all of them, and you have finished the job with exactly the result you said you would. We are very pleased.

Thank you so much and please pass on our thanks to the team.

Todd and Paula (Landlords), July 2010

Minimising Excavation

‘Trenchless’ technologies (also called ‘no-dig’ technologies) are technologies and methods that enable the installation, repair or replacement of underground pipes with minimal excavation. By minimising excavation, trenchless technologies significantly reduce the impacts of pipe installation and rehabilitation. As a result, trenchless technologies are recognised by the United Nations Environment Program as Environmentally Sound Technologies.

There are 3 key types of trenchless technologies – those employed for new pipe installation, existing pipe repair and existing pipe replacement.

Exclusive services

New Pipe Installation

Drills are used to bore an underground cavity for the subsequent or simultaneous insertion of a new pipe. However, a completely new alignment requires all connecting pipes to be rerouted. Further, as subsurface space becomes less available, the application of these technologies becomes less attractive:

“……there are so many other utility apparatus occupying the already congested footpaths and carriageways – water, sewer, gas, electrical – it is difficult, and on occasion impossible, to obtain an unobstructed route to lay a new asset.”
Robby Ollerhead, WestNet Energy

Another key disadvantage of installing a new alignment is an increased risk of damage to neighbouring subsurface assets from, for example, the drill becoming misaligned or unidentified sub-surface assets. In contrast, replacement methods are applied within the (safer) confines of the original trench. Finally, most drills cannot achieve the grade required for gravity-fed sewer pipes.

Existing Pipe Repair

Internal liners can be used to patch or completely reline the internal barrel of existing pipes. There is a wide range of pipe relining products on the market, each with its own cost and quality profile. A key benefit of pipe lining products is that they only require an average of 5% of surface excavation compared to open-trenching.

However, relining products also carry many disadvantages:

  • Relining products reduce the inner diameter of the pipe. A reduction in diameter is often unacceptable for pipe owners, particularly for industrial pipes and public mains where population growth or increased housing density requires pipe diameters to be upsized.
  • Relining products can incur difficulty forming a smooth surface (particularly at bends and corners) leaving catchment points for sewage
  • Pipe owners carry the risk of reliner longevity. This includes reliners pulling away from the existing pipe and junctions and the risk of subsequent root invasion. Perhaps the greatest risk however is the risk of a reliner collapsing during the sudden load transfer that occurs when the existing pipe ultimately fails. Whilst some relining products are guaranteed, such guarantees do not protect pipe owners from their primary ownership risks and legal liabilities
  • Most relining products are not applicable to pressure pipes including potable water and gas pipes.
  • Relining products can release toxins during and after installation which can damage water systems, air quality and neighbouring assets (such as manholes)
  • Relining products can be very noisy to install.
  • The installation of relining products involves ‘inefficient’ expenditure that would not otherwise be incurred if the pipes were completely replaced. For example, prior to installing a reliner, the existing pipe must be root-cut and cleaned (often up to 4 times). Similarly, full CCTV inspections must be completed at least once prior to reliner installation (to prove the quality of reliner preparations) and 12 months after installation (to prove the longevity of the reliner).

Existing Pipe Replacement

The only trenchless technologies that enable the complete replacement of existing pipes with an equivalent or upsized diameter pipe are ‘pipe bursting’ technologies. On average, pipebursting require between 5% and 20% of the excavation associated with open-trenching.

Pipebursting results in the installation of new polyethylene (PE) pipe on the same grade and alignment as the existing pipe. PE pipe is well regarded as premier quality pipe and is estimated to have a service life well in excess of 100 years. PE pipe is employed because it is more durable, more resistant to root invasions and more flexible (enabling a much smaller entry pit).

There are 2 key types of pipebursting technologies:

  • Pneumatic pipebursting technologies involve a pneumatic cone-shaped head that ‘punches’ its way through the existing pipe. The pneumatic head bursts and disburses the existing pipe and simultaneously draws in a new pipe. This is the ‘early’ and most common technology.
  • Static pipebursting technologies involve a static cone-shaped head that is pushed (via rods) or pulled (via a cable) through the existing pipe. As with pneumatic pipebursting technologies, the static head bursts and disburses the existing pipe and simultaneously draws in a new pipe. However, static pipebursting technologies are preferred to pneumatic pipebursting technologies because they are quieter, less aggressive and more directionally accurate. In addition, static pipebursting technologies do not introduce contaminants (such as pneumatic hoses and oil) into the inner barrel of the replacement pipe.

Pulling cables are also preferred to rod-based tools because pulling cables are safer, faster and can navigate multiple bends and corners. Static pulling cable technologies were originally developed and patented by TRIC Tools Inc. RePipe holds the exclusive rights to TRIC patents.

There are a number of reasons I think RePipe’s pipebursting tools have an advantage over other pipebursting tools. The main reason is that they are far safer…….there is less heavy gear, the cable system also means you can do longer runs, it is quicker, the access pits needed are considerably smaller and you don’t need as many of them which in turn means less reinstatement and lower cost. And on top of all that it is much quieter.
Robby Ollerhead, WestNet Energy

When maintaining or upsizing pipe diameter is not a requirement and when site conditions don’t support pipebursting, it is possible to simply insert a replacement pipe inside the barrel of the existing pipe (also known as pipe lining or pipe relining). There are 2 key insertion methods:

  • Sliplining involves the insertion of a smaller diameter replacement pipe without fracturing and disbursing the existing pipe. Overall, sliplining can reduce installation risks as all sub-surface activity is contained to the inner barrel of the existing pipe. However, sliplining results in a reduction in diameter and flow capacity. In addition, consideration must be given to how operators will access the (fully encased) replacement pipe for future connections and repairs.
  • Swagelining involves pulling a replacement pipe through a diameter-reducing die immediately prior to insertion. Once inserted, the pull pressure is released allowing the replacement pipe to expand against the inner wall of the existing pipe. Compared to sliplining, this method results in a smaller diameter reduction but also involves greater installation risks. As with sliplining, consideration must be given to how operators will access the (fully encased) replacement pipe for future connections and repairs.

Related Media

WestNet Gas Mains Relay Video
Burswood Sewer Main Upsize Slide Pack

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