Iron and copper compounds in the system are often a result of which process?

The formation of iron and copper compounds in a system is primarily linked to return line corrosion. This process occurs when water, typically from a boiler or heating system, circulates through pipes and components where reactive conditions exist. The return line often has lower temperatures, potentially leading to the condensation of corrosive gases or chemicals, like carbon dioxide and oxygen, which can promote corrosion in metal components.

Iron and copper compounds can arise due to galvanic corrosion, where different metals in contact with an electrolyte create a potential difference. In a return line, the mixture of metals—such as iron from steel components and copper from piping or fittings—can result in the formation of various corrosion products as they react with the water and other environments within the system.

In contrast, thermal expansion primarily concerns the physical expansion of materials in response to heat and doesn’t directly relate to the creation of chemical compounds. Valve malfunctioning typically affects flow and pressure control but does not inherently lead to corrosion product formation. Pump failures can disrupt fluid circulation but likewise do not directly cause the reactions that yield iron and copper compounds.