Richard Swan, Head of Technical at Dyno-Rod, looks at the latest technical developments in trenchless technology and how they can provide a solution to many different problems in drains and sewers.
September 08, 2010 // Franchising.com // Trenchless technology is a well established method and is now widely used for both complete drain replacement and localised repairs following breaks in underground pipes or deformed sewers caused by a variety of problems, such as subsidence, damage due to ground or traffic movement, the invasion of tree roots and corrosion. Correctly applied, the technology can deliver significant savings in terms of manpower, time and cost, with the potential to reduce health and safety risks, minimise disruption to the public and businesses alike as no excavators or diggers are required.
Successful application, however, depends on a good understanding of the different technologies available, including sliplining, pipe bursting, localised repairs, re-rounding and cured in place pipe (CIPP) lining, and an appreciation of which should be used to resolve different drainage problems.
Additionally, in the commercial environment, it is uncommon for larger organisations to have standardised or central policies in place, so that it is easy to identify and remedy drain faults quickly and cost effectively. These kinds of businesses typically have a single solution, often CIPP, making it difficult to tailor the job to the problem in hand.
In answer to this, leading companies now offer an extensive range of no-dig solutions combining many of the most effective techniques making it easier to find a remedy for specific problems. For example, Dyno-Rod has developed the "No-Dig" Toolbox which is a resource that uses various dedicated methods for the quick and effective repair of private sewers and drains with pipe diameters from 50mm up to 1,200mm, without the need for excavation, trenches or large access pits, which by its very nature also significantly improves health and safety for workers.
In particular, the "No-Dig" Toolbox caters for many different problems. For example, Localine is a solution that has been designed to target isolated faults in hard to access drains and sewers for a one off permanent repair. This system enables breaks, holes or fractures to be repaired in drains and sewers with 100mm to 1,200mm diameter clay, concrete, metal or plastic pipes. This innovative method eliminates the need to replace or reline full sections of pipe as a permanent, water tight finish is bonded directly to a specific area of the pipe wall.
Unlike conventional techniques, which often required relining the entire length of a pipe from manhole to manhole or digging it up to replace it completely, Localine uses a fibreglass sleeve that is impregnated with a silicate resin and is carefully passed through the host pipe to the point of the fault. This sleeve is then inflated, pushing the resin and glass mating into place and allowing it to bond tightly to the pipe wall. As the resin quickly cures, the repair is completed restoring the pipes structural integrity.
Traditionally, a damaged pipe in complex drain systems often spelt out extensive digging and excavation in order for it to be repaired. To overcome this problem, Dyno-Rod uses the highly effective Brawoliner System to renovate problematic drainage systems. This technology uses a seamless, elasticised polyester sock with a flexible, leak free inner lining that can navigate multiple bends up to 90° in a pipe, smoothly sticking to the contours as it goes without creating unwanted folds or wrinkles to ensure optimum flow. The lining is impregnated with an epoxy-based environmentally friendly, odourless resin which is cured by hot water to create a new pipe within the existing broken pipe. Brawoliner 3D has the added benefit of being able to line pipes where the internal diameter changes from either 70mm to 100mm or 100mm to 150mm.
Similarly, a patented system has been developed to restore deformed pitch fibre pipes without the expense and inconvenience of traditional excavation. Indeed, Dyno-Form combines drain relining techniques with the use of specially designed equipment for re-rounding a deformed pitch fibre pipe. An innovative re-rounding tool is carefully passed through the drain to compress the existing pipe into the sub-strata and restore the original bore following which the pipe is lined with a new cured in place pipe to restore integrity and water tightness.
This method has proved highly effective in restoring pitch fibre pipes and since 1996 Dyno-Rod has renovated over 150km of pitch fibre pipes and is now recognised as an accepted approach where the deformation of the pipe is less than 20% of the original diameter. However, if the pipeline deformation is greater than this, it is often more advantageous to use the unique in2 Pipe Replacement System, which allows drains and sewers to be replaced completely with new, durable, factory produced plastic pipes.
The WRc Approved in2 Pipe Replacement System uses 100mm or 150mm diameter pipes, with a lifespan of over 50 years that are inserted into the void once the damaged or distorted sections of original pipe have been reformed or cleared using specially designed tools. These are easily installed through a standard manhole or small excavation, with each pipe section being screwed to the last and then either pulled or pushed along the void until the old pipe is completely replaced, creating a leak free seal.
When it comes to a burst or leaking pipe in sewer and drainage systems, repair is almost always urgently required to prevent a whole host of other problems. With the latest trenchless technology, drains can now be repaired quickly and cost effectively without the environmental issues including the upheaval, mess, noise and health and safety issues normally associated with the excavation often required in traditional repair methods. As a result, disruption to both organisations and the public are reduced to an absolute minimum allowing business to carry on as usual without any inconvenience or profit damaging downtime.