Search in site

Preventing Corrosion

What causes corrosion?

Corrosion occurs when a refined metal reverts back to its natural ore state. Corrosion in water systems takes place when two areas of metal with a different electrical charge are in contact or linked via a conductor such as water.

What should be done?

An inhibitor should be added to system water to reduce the rate at which corrosion takes place. To determine the existing level of protection simply use the Fernox Protector Test Kit or a 60-second Protector Check Strip to measure the concentration of inhibitor within the system.

Over and under-dosing with inhibitors
Although manufacturers specify a recommended dose rate for their product, it is important to find out how a product performs when over or under-dosed. Anodic passivating products will require a sufficient dose to ‘coat’ the internal surfaces of the system, plus some excess to maintain this film. If the dose is below the level required to achieve sufficient protection, exposed areas of metal will continue to corrode. Over-dosing with anodic inhibitors is unlikely to have any detrimental effect. Oxygen scavengers and cathodic inhibitors will not be fully effective if under-dosed, but will have a partially protective effect.

Negative impact of contaminants
The presence of contamination by flux residues, existing corrosion sludge, residual cleaning agent, or even washing-up liquid may adversely affect the performance of an inhibitor and lead to corrosion. To make sure an inhibitor performs as effectively as possible, it is advisable to clean the system thoroughly before treating. The Fernox Water Test Kit or Total Dissolved Solids (TDS) Meter can be used to check that a system has been adequately cleaned and flushed before an inhibitor is added.