Corrosion is accepted as an occupational hazard simply because there is no way to completely stop it. Over time, this will have a negative effect on the lifespan of your equipment. A phosphate ester corrosion inhibitor fluid is the most widely accepted and optimal method used to slow corrosion.
Combating Oxygen
Oxygen plays a major part in the corrosion process. There is no clear reason as to why it is present in systems. The majority of corrosion inhibitors used offshore were developed under the assumption that there would not be any oxygen present in the system.
For this reason, most corrosion inhibitors perform poorly in environments where oxygen is present. This includes applications that use water. In most cases, additional chemicals have to be added in order to manage the increasing corrosion that comes from the injected oxygen. The most popular is the phosphate ester corrosion inhibitor.
The performance of the phosphate ester corrosion inhibitor has been tested against commercially available imidazoline-based corrosion inhibitors. The goal of the test was to determine if the phosphate ester would reduce the number of additional chemicals that must be added to traditional corrosion inhibitors.
With imidazoline, there is not a lateral reaction between the absorbed molecules. Phosphate is absorbed strongly on surfaces of oxidized iron. Because of this, the phosphate ester corrosion inhibitor presents a higher impedance of the cathodic current in comparison to the imidazoline-based inhibitor. A film is produced on the surface, preventing water from getting to it in a process referred to as geometric coverage.
