Trenchless rehabilitation of drinking water systems and pipes using food grade resin

ART Europe specialises in the trenchless rehabilitation of drinking water systems with a system entailing the spray application of food grade polyurethane resin.

Drinking water systems deteriorate under the impact of a number of factors and pipe failures appear such as leaks, corrosion, scaling, restricted flow and impairment in the quality and taste of the water. We undertake the renovation of these pipelines in order to increase their longevity and improve the quality of the drinking water they carry.

Local and regional authorities and private businesses call on our services for the trenchless rehabilitation of pipes and systems, a less expensive and faster technique than pipe replacement.

Our trenchless drinking water system rehabilitation solution

The renovation of drinking water systems presents a significant challenge. With our process of drinking water pipeline rehabilitation involving the spray application of food grade polyurethane resin, we offer a fast, efficient and economical solution that can be adapted to a variety of pipe diameters and lengths.

This technique restores the initial properties of the drinking water system (flow, turbidity, taste), upgrades it and extends the service life of the pipelines without the need to open trenches and with a reduced intervention time, unlike open-trench works which cost more and take longer.

Our product: food grade polyurethane resin sprayed onto the walls of the drinking water system, thereby renovating it.

Applied equally effectively to steel, unlined cast iron, concrete or asbestos pipes, the fast-drying food grade polyurea resin can be applied to the interior of all pipeline diameters from DN 60 to DN 2000 mm

Sprayed internally with the deployment of a mobile robot, the resin forms a new protective layer inside the pipeline.

 *Nominal diameter

Polyurethane resin is a two-component resin with a base and an activator. It is sprayed over the interior of the existing pipeline in order to shield the pipe from the aggressive action of water. It can be applied to a thickness of up to 3 mm per layer and is touch-dry after just a few seconds. Multiple layers can be applied to achieve a thickness of one or more centimetres.

Water can be restored to the system after one hour.

The food grade polyurethane resin is attested by a Sanitary Approval issued by the French General-Directorate for Health.

How the rehabilitation of a drinking water system is carried out

This process involving the spray application of resin from the inside makes it possible to renovate pipelines without opening up trenches. Earthworks are only required at each end of the system, and water needs to be shut off on the section in question on the day of the works.

What exactly does the upgrade of a drinking water system entail?

Once the footprint of the works has been established, the access shafts dug and the section of pipeline requiring rehabilitation isolated, the operation can be completed in one day, with between 100 m and 180 m of pipe rehabilitated per section.

It is a 7-stage process:

1. Earthworks at each end of the pipe section (to be carried out prior to the day of intervention).
2. Water cut-off and neutralisation of the section requiring treatment.
3. Cleaning of the interior of the pipe by means of mechanical rodding, a crucial phase in achieving a clean substrate prior to the application of the resin. A rotating head is introduced in order to strip the pipe surface, removing the deposits of calcite and corrosion built up over time. Hydraulic rinsing is carried out simultaneously in order to remove residues as the operation progresses.
4. Drying by means of a foam pig, which absorbs the water remaining in the pipe.
5. Camera-controlled televised inspection to check the pipe cleaning and drying operations.
6. Application of the fast-drying food grade resin to the chosen thickness (from 1 mm to 3 mm per spray application) using a robot linked by an umbilical cable with no need to redrill any connections after the works. Multiple layers can be applied, in particular if the pipeline is in a very dilapidated state.
7. Televised visual inspection by passing a camera through the section in order to validate the adhesion and homogeneity of the coating applied.

The resin applied can be used in other systems (untreated water, rainwater, industrial water).

Regardless of the thickness sprayed, the service life of the resin is guaranteed for 30 years by the manufacturer. For its part, ART Europe provides a ten-year "assurance par capitalisation" (self-insurance based on investment) for all rehabilitation operations carried out.

What are the benefits of pipelining with polyurethane resin?

Pipelining offers numerous benefits:

• Technical benefit: the resin completely covers the internal wall of the pipe and seals it. It lasts for more than 30 years
• Economic benefit: there is a reduced need to dig up roadways and the pipes are not replaced, minimising the cost of works compared with open-trench replacement.
• Environmental benefit: the short duration of the intervention minimises disruption to the environment and to local residents during the works. The restoration of a safe and reliable pipeline reduces the need to treat drinking water with chlorine.
• Quality benefit: the approved coating is a highly adhesive and non-shrink resin, guaranteeing the longevity of the pipelines (expected service life of more than 40 years), enhanced water quality and improved original hydraulic performances. The resin applied provides long-term protection against corrosion and excellent abrasion resistance.

Example of pipelining projects

Rehabilitation of a drinking water pipe in Thonon-les-Bains

Rehabilitation of the drain pipe at the Ortolo dam in Corsica

ART Europe also offers its services for:

Other rehabilitation services

Sanitary plumbing