High Performance Fabric In Old Piping: Quick, Durable Restoration Of Operational Safety

By Andreas Hüttemann, Qualified Engineer Director, R&D/Quality Management, Karl Weiss Technologies and Brian Mattson, Business Development Manager, GTI | December 2009 Vol. 64 No. 12
Fig. 6 Woven fabric reversion of pit three toward pit one with a length of 994 feet.

Feb. 11: A team of experts gathered in Berlin’s district Mitte, at the relevant Berliner Water Works pipe network operating facilities from the domain of pipe work damage. This is one of five operating facilities in Berlin. Appropriate measures for long-term removal of pipe work damage are discussed. The general conditions are made clear during the course of the meeting:

  • The pipe network database shows that the pipe has already been damaged on several occasions and therefore a high probability of failure exists;
  • The pipe is situated underneath three newly constructed sports fields and a school yard;
  • The pipe network calculation experts determine that the cross-section must remain; and
  • Due to dependency on other building work and the impending summer time, a brief removal from service is possible for only a few weeks.

As a result of the discussion it was decided that the condition of the pipe would be determined by a test shafting and pipe cuttings.

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Fig. 2
Lining of the pipe inner wall through holohedral and exfiltration sealed bonding with a smooth, circularly woven fabric liner made from high-strength and non-ageing fibers.

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Fig. 3
Layout of pits and sections of the piping with a length of 994 feet in section 1 and 721 feet in section 2.

Decisions
Two weeks later: Operations for the production of two pits are severely hindered by retained water and because of weather conditions. From interim research of the plan archive, it emerges that the pipe suffered bomb damage in 1944 and was replaced with steel in several areas. Furthermore, the material tests on the pipe cuttings show that in essence, the grey cast-iron material has a residual wall thickness of 11/16 inches. For the areas with steel piping, it must be assumed that it is highly corroded because of corrosion protection applied at that time (use of bitumen or tar). Deposits and incrustations from the pipe only exist on a low scale. As a result of the examined pipe cuttings, the pipe is classified as being able to be restored.