Monday, July 15, 2024

Renovating Sewer Rising Mains

The Primus Line® system has already proven its suitability for rising mains in numerous installations.

The renovation of sewer rising mains is often delicate. That is why operators are increasingly looking for trenchless rehabilitation methods. One of them is Primus Line® – a tried and tested technology.

Many sewer rising mains have several things in common: They are a critical asset to the asset owner, as it is often complicated to divert the flow for an extended period of time. The accessibility to the pipe is mostly difficult, as the mains run through densely populated or environmentally sensitive areas or under creeks and main roads. The pipelines often have several bends in the run of the main. Faulty sewer rising mains have the potential to cause pollution, damage property and neighbouring services, resulting in significant costs.

Failures on rising mains can be caused by external corrosion, internal corrosion or mechanical failures like leaking joints, longitudinal cracks, etc. In many cases the pipeline is still able to withstand the traffic loads, but not the internal pressure loads. A renovation using sewage lining or slipining with HDPE is often not acceptable due to the significant diameter reduction, the limitation of installing through bends, the pit sizes and the duration of the installation.

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The Primus Line® system, engineered and made in Germany, offers a solution for this extraordinarily difficult scope. The system consists of a flexible Kevlar-reinforced liner and special end fittings. Primus Line® offers small installation footprint, a wall thickness of only 6 mm, the flexibility to be installed through bends, including consecutive bends, the possibility to reline 500 m and more in only one day, and to achieve installations shots, pit to pit, of 1,000 m and more. In addition, Primus Line® is installed with an annulus, thus the installed Primus Liner will accommodate the operating pressure and will release the host pipe from bearing the internal forces and therefore stop the aging process of the existing main caused by the operational loads and internal corrosion. The Primus Liner is a factory-tested product that is delivered on a transport reel to the construction site. After CCTV surveying and cleaning the existing main, the pre-folded liner is winched in position and inflated using only compressed air. Subsequently, Primus Line connectors are installed and a pressure test completes the installation process.

TRIED AND TESTED TECHNOLOGY

The Primus Line® system has already proven its suitability for rising mains in numerous installations. The renovation of a DN 600 sewer trunk main for the City of Gold Coast, Queensland, Australia was even awarded “ASTT Rehabilitation Project Of The Year 2019”. Within only two working days, a leaking MSCL sewer force main, which runs under a creek, was renovated with the Primus Line® system. The existing pipeline has six opposing bends in a section of only 50 m length and operates with 4 bar/40 m head.

Also a major UK Utility company used Primus Line® for the rehabilitation of a DN 500 and DN 400 twin sewer rising main. McAllister Group installed the complete 650 m length for each of the host pipes in a single installation. The rising mains ran parallel with each other but from different pumping stations, had a number of changes in direction both vertically and horizontally, but more significantly had been overbuilt to extend the original ‘A’ road with a new dual carriageway. The dual carriageway was built on a raised reinforced bank. Each of the rising mains had experienced recent bursts that caused significant local disruption. Traditional open cut methods to replace or repair the mains were considered earlier by the client as a last resort. Excavating near the reinforced bank would have added unnecessary risk and considerable cost to the project.

The combination of strength and flexibility of the Kevlar fabric, the high safety factors on the material and the extended asset lifetime of 50 years and more can make Primus Line® a suitable fit for the rehabilitation of sewer rising mains. Website: www.primusline.com

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Newsdesk
Newsdesk
Trenchless Works bringing you balanced journalism, accuracy, news and features for all involved in the business of trenchless and no-dig from around the world

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