Most buildings services engineers will have come across a heating or cooling system that has not been treated correctly and still appears to function perfectly and another that has apparently been treated but experienced serious corrosion related failures. Why should one be vulnerable and the other not?
The answer is that most common metals are subject to corrosion, but the rate of corrosion and risk of failure depends on a variety of factors including the chemical and microbiological environment, temperature, flow rate and at least the thickness of the metal.
“What happens in the first few weeks of the life of the system will influence its fate over the next 25 years. You can’t easily see what is going on inside a pipe, but get it wrong and you could be looking at major remedial works in a tenth of that time”.