Corrosion
Various metals have different tendency to corrode. When different metals are used in a liquid system there is always a risk that the less noble metal starts to corrode. The conductivity between the electrolyt and the metal decides the corrosion rate. A high oxygen level in the fluid also implies a higher corrosion rate. Electrons migrate from the metal out into the electrolyt and a corrosion attack starts.
Traditional corrosion inhibitors
Traditional corrosion inhibitors protect the system by forming a mechanical film that covers the metal surface. The protective film can reduce heat transfer by up to 20%. There is also a risk of damaging the coating. Moreover, it is difficult and expensive to examine the quality of the protection. Every part in the whole system must be inspected to make sure that the coating is intact. Normally this is impossible.
Temper corrosion inhibitor
Temper contains a special corrosion inhibitor which does not form a general mechanical protective film, but which instead acts only where electronic potential differences arise. The molecules of the inhibitor accumulate at the corrosion-prone site, where they form an extremely thin local layer. This layer locally eliminates the risk of corrosion, with practically no effect on heat transfer. The Temper corrosion inhibitor is not consumed: Once the electric potential difference is equalized, the inhibitor molecules are released and are free to accumulate at any other site where there is an electric potential displacement (see the diagram below). With Temper, it is very easy to assess the corrosion condition of a system by determining the number of “free” inhibitor molecules. If the number of free inhibitor molecules falls below a given value (which might even happen when filling a system with Temper for the first time, i.e. when corrosion products are already present) optimal corrosion protection can be restored by adding pure inhibitor fluid. If necessary the density (freezing point) can also be adjusted.
Corrosion on copper, steel, cast iron, aluminium alloy and brass is very low according to test ASTM 1384:87 (at 88°C).