Monaco on the Cote d’Azur is for many the place for the rich and beautiful of this world. Who doesn’t know the pictures of the casino, the big yachts in the harbour or the Formula 1 racing cars thundering through the gorges of houses?
In Monaco there is also the Tour Odeon. This skyscraper houses the most expensive penthouse in the world. It is said to have cost more than 300 million USD and covers the top 3 floors.
Corrosion in stainless steel pipes
As is to be expected, this building is state of the art. Of course, only materials and machines of the highest quality are used. And these are also installed with great care as you can see on the pictures. All stainless steel piping and stainless steel valves. Cleanly insulated with rock wool and metal cladding. Against heat loss in hot water or to avoid condensation on the outside of the pipes.
There are 3 water and energy supply centres in the building. One in the basement, one on the 20th floor and one on the 40th floor. There are several reasons for this. On the one hand, it is not economical to pump water from the cellar 170 metres up to the top floor. 170 meters of water column correspond to 17 bar counterpressure. On the other hand, the heat loss would be too great if hot water were circulated over such a distance. In each of these central units there are pumps, hot water boilers and a classic water treatment system to supply the apartments above.
Despite the high quality of the materials used and the chemical water treatment, the stainless steel pipes have started to rust. This first manifested itself in the slightly brownish water on the washbasins. A few weeks later it also came to pitting. Almost exclusively in horizontally laid pipes. When we first visited the site, about every 2 months a piece of stainless steel pipe had to be replaced becasue of pitting.
The rust and the pitting have disappeared
The reason for this rust, or better said the corrosion, cannot be clearly determined. The Tour Odeon is supplied with water and electricity from two sides for safety reasons. The water comes from different sources. If these two waters are mixed, this mixed water can become aggressive and lead to corrosion and pitting.
The most likely scenario is Merus:
– Not all apartments are occupied all year round.
– So no water flows for weeks or months.
– This can lead to rust formation even in stainless steel pipes.
– This grate is washed out the next time it is used and then collects on the horizontal pipes in the energy centre.
If this assumption is correct, then the rust particles on the stainless steel are the reason for the pitting in the stainless steel pipes.
Or probably it’s a mixture of both. The aggressive mixed water stands too long in unused pipes, removes ions from the stainless steel and rust develops.
We have installed Merus rings at each of the two inlets into the house. As well as in the flow of the hot water circulation, as shown in the picture on the right.
At the beginning, the customer rinsed the system thoroughly to remove rust. In addition, some of the eye-catching wash basins have been regularly inspected.