What causes an evaporator coil to rust?

- Mar 13, 2019-

What causes an evaporator coil to rust?


In daily life, iron products are easy to rust after a period of time, and the evaporator is the same. Some people may have some doubts. Is the evaporator  not made of stainless steel? Why is it rusty?


This is because the stainless steel surface has a protective film. In a dry and clean environment, the stainless steel will not rust. When the stainless steel encounters acid, alkali or salt, it will easily rust.


Due to the different water quality in various places, there are more hard waters in the north and more soft water in the south. The steam generator produces scale when long-term use of hard water containing more calcium, magnesium, Mg and other minerals. The scale component is alkaline CaCO3, Mg(OH)2, which forms corrosion rust and destroys the stainless steel surface protective film. Therefore, after using it for a period of time, it is necessary to clean the scale regularly. You can pour some citric acid or vinegar in the evaporator or the kettle, and heat it to dissolve.


In addition, the generation of steam generator scale has a great relationship with the pH value, and the pH value is too high or too low. Therefore, it is necessary to do daily care. In general, you should pay more attention to avoid metal rust and prevent precipitation of calcium and magnesium ions. Only in this way can the steam generator itself not be corroded and prolong its service life.