Definition - What does Immersion Service mean?
Immersion service refers to the use of a metallic object or metal structure in an industrial application that requires the structure to be completely engulfed or surrounded by a liquid. Metals in such applications are at a significantly higher risk of immersion corrosion.
Corrosionpedia explains Immersion Service
Metal structures that are used to provide immersion service should be tested and/or inspected regularly for corrosion in order to prevent equipment failure. Water immersion testing is done to verify the passivation process on nearly all grades of stainless steel.
The governing and most widely used standard for immersion corrosion testing is ASTM G31. It provides a direct and simple method of determining the rate of corrosion in aqueous solutions.