Internal Pipe Repair

Since its foundation, Donauer & Probst has been successfully active in the segment of internal pipe repair, an innovative technology for the non-destructive repair of drinking water pipes in residential and commercial buildings. The public’s interest in this “soft” repair method is continuously increasing. Thanks to the constantly optimised internal development of the DonPro method, Donauer & Probst is able to consequently translate its many years of experience with the requirements of the housing industry into success.

More than 1,200 buildings in over 15 years: our track record in the renovation and restoration of classical detached houses and blocks with more than 500 apartments serves to document the method’s success. Especially in hospitals, hotels and public buildings, in which renovation work must not lead to an interruption of the ongoing business, internal pipe repair has proven its efficiency.

And this is how it works:


  • Preparing the pipe
    In a first step, the pipe string is separated from the remaining pipe system and drained completely. In cases where a system with only one pipe string is used, we can, upon request, also install an emergency water supply system.
  • Blowing the pipe
    The fittings, right-angle valves, water meters and UP/AP valves installed on the string are removed and replaced by special hose couplings. Then, cold-dried and re-heated air is blown through each of these couplings into the string to ensure that the string system is absolutely dry.
  • Sandblasting the pipe
    Blowing and drying the pipe is followed by sandblasting. To this end, a special granulated material is blasted into and sucked out of the pipe using a special sandblast apparatus. This helps to remove internal corrosion without harming the material.
  • Coating the pipe
    After cleaning, the pipe is coated with an epoxy resin that has been especially developed for drinking water supply systems and has been rated by the German Health Authorities as “safeguarding the drinking water quality”. What we get, is a new pipe within the old pipe. Already after 12 to 14 hours, the pipe can be put into operation again.