Pipe rehabilitation - saving old pipes?

If rust or lime has damaged the pipes over time, that's not only uncomfortable. These problems can also lead to a pipe burst in the end. Many then commission a pipe rehabilitation through a specialist company.

Brown water from the tap?

Especially if no water has been withdrawn for a few days, for example after vacation, those affected notice that their tap water is coming out of the tap brown. If you let the water run for a while, the brownish color will disappear again.

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But this discoloration is the first sign of a much bigger problem with the water pipe. If nothing is done now, the water pipe can burst within a short time.

Causes of damaged lines

Even the cleanest drinking water contains both lime and a small amount of sand. Hard water, i.e. calcareous water, can attack the galvanized inside of an old steel pipe.

At a kink or curve in the pipe, the flow velocities and turbulence can lead to rust. Especially in a hot water pipe, a water temperature of over 60 degrees damages the galvanized pipe.

In the case of a copper pipe, pitting is usually caused by foreign matter that has washed in, such as rust from other connected pipes.

Pipe cleaning

Before the pipes are rehabilitated, the interior is cleaned. There are three different methods for doing this. While some providers rely on a dry cleaning process, others use an allegedly gentler wet cleaning process.

Then there is also a chemical cleaning of the inside of the pipe. However, this is not advisable because of the severe environmental pollution and the low level of success.

  • Dry cleaning
  • Wet cleaning
  • chemical cleaning process

Dry cleaning

With dry cleaning, sand is shot through the pipe. In principle, this is the same as sandblasting external surfaces. However, the direction of the sandblasting could be a problem.

The sand is only blown through the pipes in one direction, so so-called shadow areas can arise where the rust remains. The coating would then have no effect here. In addition, due to the heavy load of sandblasting, an already very thin area could break through completely.

Wet cleaning

With a compressor, water is blown through the pipe at high pressure in both directions. The pipes are then rinsed and dried. This method is supposed to be gentler, but a pipe rupture can also occur here.

Pipe rehabilitation

Most companies use a two-part epoxy to coat the dried and cleaned pipes. The epoxy resin lends the pipes a complete layer of plastic on the inside.

This method is even endorsed by the food inspectors and the food law.

Tips & Tricks The real problems with pipe rehabilitation are basically the cleaning. All variants have difficulties if the pipes are already badly attacked. At the same time, there are no really meaningful studies on how the epoxy resin gets along with drinking water in the long term.

It is therefore absolutely important to find an experienced professional who gives a guarantee of a few years on his work if possible.