Cast Iron pipes from 1968 repaired in south western Germany.

The Heersbergweg in Burgfelden will be renovated in spring. © Photo: Horst Schweizer

Near the Swiss / German border in an area where the largest city is Albstadt, lies picturesque villages and good hiking. Last year in November, two cast iron pipes built in 1968 were set to be repaired after several bursts were discovered on a line that leads from a pumping station in Margrethausen up to a reservoir on Heersberg.

Amex Sanivar has worked closely with Albstadtwerk - the local energy and water service provider in the area - for years. This relationship helped seal this project, with Amex Sanivar installing its flexible pull-in-place liner SaniTube®.

Challenges

There were several challenges that had to be addressed before Amex Sanivar was chosen. First, due to the altitude of the reservoir, the pipes are under a 4 bar operating pressure. The chosen liner needed to be able to withstand more than 4 bar to be able to provide a long-term rehabilitation solution. Additionally, the liner needed to be installed in winter. "During this period, no growth is damaged, and there are no ground-nesting birds," says Frank Tantzky - Head of Construction and Maintenance at Albstadtwerke. So, due to potential dips in temperature, the chosen liner would need to be able to installed in cold weather. Finally, because the installation area runs along a hiking path, the construction footprint needed to be kept to a minimal.

Trenchless rehabilitation solution SaniTube® was chosen because it addressed the challenges of the job perfectly. SaniTube® can withstand pressures up to 16 bar, requires no adhesive meaning it can be installed in any weather, and due to the minimal installation equipment required SaniTube® is perfect to be installed in highly sensitive areas.

Conclusion

The installation took place in November, 2023. SaniTube® was installed in 50 meter segments, with each segment being reconnected to the host pipe using SaniGrip® couplings. Albstadtwerke was particularly happy with the installation, because the internal flow rate had decreased substantially over the 55 year life of the pipe due to substantial deposits in the pipe.

"With the new, internally smooth special hose, we now have 30 percent more flow," says Frank Tantzky. Speaking of both Amex Sanivar and his team at the Albstadtwerke, Frank continued, "they did a great job, even when rain and snow came horizontally, work was not interrupted."

SaniTube Specifications

How it works

· SaniTube® consists of a textile liner, and a double-sided thermoplastic coating

· Suited for the rehabilitation of all common types of pipes DN50 to DN450

· Suitable for great variety of media: potable water, sewage, industrial applications, gas, oil, and petrol

· SaniTube® is pulled-in via standard winch and reconnected to host pipe using a flange coupling

Main advantages

· Rehabilitation of up to 3000m in a single pull – incl. bends of up to 40°

· Design life of 50 years

· No resin, no impregnation, and no curing needed

· High resistance to pressure: burst pressures of over 34 bar w/o host pipe and resistant to vacuum

· Easy installation & no need for special equipment