An interesting paper was presented at the NACE International Corrosion 2015 Conference and Expo. Download Paper Here NACE International is an association dedicated to assisting organizations with corrosion issues by providing training, research and education materials to the general public. One of the papers presented was a comparison study of corrosion protection effectiveness between Vapor Corrosion Inhibitors and Dry Air Systems.
Dry Air Systems or “Controlled Humidity Protection” focuses on minimizing exposure to relative humidity (RH). Moisture is a necessary component for metal corrosion and studies have shown that keeping metals at or below RH 40% dramatically reduces the chance of corrosion.
The Controlled Humidity Protection (CHP) method is commonly used in bridge construction and in the storage of military equipment. Unfortunately, despite positive results, there are still reported corrosion attacks on metals using this method.
An experiment was conducted on carbon steel and galvanized steel, comparing CHP with Vapor Corrosion Inhibitors (VCI). VCI blankets metal with an inert gas that contains ions that bond to metal forming a corrosion resistant surface. VCI is an inexpensive method to provide protection for long periods of time.
The results of the testing clearly demonstrated that VCI was superior to CHP in terms of both short and long term protection. The CHP method does reduce moisture level, but once corrosion sets in, the dry air system does not retard the acceleration of the corrosion reactions.
The test was performed by The Dept of Manufacturing Systems and Engineering & Management, College of Engineering and Computer Science, California State University.
Packnet is a distributor of Cortec products: Cortec is the world’s leader in corrosion inhibiting products that are environmentally friendly. These products feature VpCI (vapor phase Corrosion Inhibitors) chemistry that uses vapor pressure to effectively blanket surfaces and form an ionic corrosion resistant bond. For more information on Cortec products, please see our corrosion protection webpages.