5. Maintenance and analysis

The chemical composition of aqueous fluids in service changes continuously over time. The main causes are :

• chemical reactions in fluid components. The speed of these processes is linked to variations in pressure and temperature;

• Selective extraction of compounds adsorbed on metal surfaces or absorbed by porous structures (e.g. cast iron);

• contamination by metal ions, foreign oils, protective products or degreasing agents ;

• increased salt content in water ;

• bacterial contamination.

The fluid must therefore be analyzed to maintain it and avoid problems.

Stability is an important property. It is determined by the following parameters: