Definition - What does Condensation Exposure mean?
Condensation exposure refers to an exposure where the surface is almost constantly exposed to saturated air, accompanied by repeated or continuous condensation. Continuous exposure of surfaces to condensation environments promotes the corrosion of surfaces.
ASTM D4587 - 11 is a design standard practice for fluorescent UV-condensation exposures of paint and related coatings degradation testing. This practice induces property changes with the effects of sunlight, moisture and heat, which are believed to be causes of condensation. This is an accelerated exposure testing of coatings and related products in fluorescent UV-condensation exposures.
Corrosionpedia explains Condensation Exposure
The exposure of light, heat and water on a paint or coating surface is very significant for many applications. This exposure can change the physical and optical properties of coatings surfaces, and may cause condensation and lastly the corrosion or deterioration of surfaces. The atmospheric pollution, biological attack and saltwater exposure may aggravate the condensation situation.
Condensation can also occur under insulation, in which moisture can be absorbed from exposure to water and from a failed covering. Condensation is also built-up on adjacent surfaces or by coming into balance with prevailing relative humidity. Under insulation, moisture cannot be driven out until the insulation temperature reaches approximately 314°F, and the net result is boiling water against the insulated surface. This is the most notorious reason for corrosion under insulation. Typically, a primer or surface protection system and thin insulation coating both keep the surface free from moisture.
Condensation corrosion can be prevented by:
- Barring moisture from contact with the surface
- Using insulation that can't absorb moisture
- Using industrial anti-condensation coatings
When condensation occurs, it may cause severe accidents, equipment failure and biological growth. The chances of condensation can be reduced by placing a thermal barrier between the substrates. Industrial anti-condensation coatings are completely fit for protecting industrial instruments, storage vessels, pipelines, ducts and tanks from moisture damage or condensation exposure.