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00CNO0192-E (U0627512)
CONDENSINOX -
Installation, Use and Maintenance
1.5.3. Protecting steel and stainless steel boilers against corrosion
Corrosion can affect the iron components used in boilers and heating
systems, which is directly related to the presence of oxygen in the water
heater's water. Dissolved oxygen that enters the unit when it is being filled for
the first time reacts with the equipment materials and quickly disappears. If
the oxygen is not renewed through significant contributions of water, the unit
might not experience any damage whatsoever.
However, it is important to follow the sizing rules and installation guidelines
in order to prevent oxygen from continuously flowing into the heating water.
These rules include:
- Give preference to an expansion vessel with a membrane rather than an
open expansion vessel that allows direct passage.
- Ensure the pressure in the installation is greater than 1 bar when cold.
- Remove leaky (permeable to gas) components and replace with sealed
components.
If the guidelines above are followed, the unit's system water has the proper
characteristics to last a long time: 8.2 < pH < 9.5 with a dissolved oxygen
concentration of < 0.1 mg/l.
If there is a chance that oxygen could enter the unit, you must take additional
precautions. Adding an oxygen scavenger (e.g. sodium sulphite) is highly
recommended. We recommend directing any water treatment questions to
specialists, who can provide:
- The appropriate treatment based on the characteristics of the unit,
- A monitoring agreement with a guarantee as to the results.
In the case of an installation in which the water comes into contact with
a variety of materials, e.g. copper and aluminium, appropriate treatment is
recommended to ensure the long-term operation of the installation. In most
cases, this treatment will involve adding corrosion inhibitors in the form of
chemical solutions. We recommend contacting a water treatment specialist.
1.5.4. Unit monitoring
If the recommendations listed above (new installation or renovation) have
been followed, the unit monitoring is limited to:
- Checking the amount of make-up water (fill water volume + make-up
water volume < 3 times the unit volume).
- Checking the pH (stable or rising slightly).
- Checking the water hardness (stable or falling slightly).
We recommend monitoring these parameters two to three times a year. Note
that monitoring the quantity of make-up water is vital to ensure the long-term
operation of the installation.
If any of these parameters deviates from the above recommendations, refer
to a water treatment specialist to correct the problem.
