SaniTube rehabilitates old asbestos cement DN 300 pipe under factory
Updated: Nov 8, 2022
Hildburghausen is a small city located in Thuringen, Germany. When many of the potable water pipes were installed, there wasn’t much around the city in terms of new development. As the city has grown, many of these pipelines have become buried under large architectural structures, rendering them inaccessible when damage occurs. This was the case in Hildburghausen starting in late Spring.
When the leak was first discovered, the client set out to fix the damage as soon as possible. The main section of the damaged pipe happened to run under a factory, however, and after consulting with the business the city was not allowed to dig on the property and any trenches around the property couldn’t be larger than 3m x 3m.
Given the tight construction requirements, the client began looking for a product that could be installed over the 250m without having to open more than two trenches, but also didn’t need large trenches for installation. SaniTube® was chosen because not only did it check those two requirements but also because it could be installed in the course of one day with the pipe being able to be reinstated shortly after pressure testing.
In addition to the small trenches and limited working space, upon cleaning and CCTV inspection a sacrificial anode was found close to the exit trench. These can be extremely dangerous and can cut the SaniTube® upon installation.
Because of this, quick decisions had to be made regarding how to proceed. It was decided that the best way to proceed was to cut out the small section of the pipe with the sacrificial anode and then replace this freshly cut out section with pipe that was removed when making the trenches. This section of pipe was then reconnected to the host pipe using external pipe clamps.
Why CCTV is important
While SaniTube® requires no adhesive to cure to the host pipe, the pipe must be free of intrusive objects that could cut it.
Quite often things like sacrificial anodes have been forgotten about and can only be discovered by doing a CCTV inspection of the pipe. Had the client in Hildburghausen not conducted a CCTV inspection, the sacrificial anode would have cut the liner, causing serious problems.
After the sacrificial node was removed and the host pipe reconnected at this point, the SaniTube® could be installed. The liner was pulled through without any problems, reinflated, and the SaniGrip® couplings fixed tightly. Once this was done pressure testing was conducted and the line was deemed fit to be reinstated.
Upon re-instating the host pipe, extra asbestos pipe was cut to cover the exposed SaniTube® that remained after the SaniGrip® was installed. When the line was fast and secure, the pipe could be reinstated.
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
· 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