Cold Storage Tank with Spray Polyurethane Foam and Vapor Retarder

Spray polyurethane foam is a very efficient insulation used extensively in the cryogenic tank industry. Closed cell spray foam offers an R-value of up to 6.5 per inch. This lightweight but very durable product is ideal for such cold storage and tank applications.

Project Application 

In this project, tanks were put into service to hold liquid CO2 for dry ice production. The liquid CO2 is held in storage tanks at temperatures of -15F and colder until needed in the production facility. Once these 75 foot long tanks were put in place, they were primed with ALDOPRIME 624 to insure maximum adhesion of the BASF closed cell spray polyurethane foam. Once primed, the BASF SPF was applied in multiple passes to achieve a total thickness of 6 inches.

The next step was to apply ALDOCOAT 660 Butyl Thermoplastic vapor retarder coating is multiple passes to achieve a dry film thickness of at least 25 mils. The use of a vapor retarder coating is critical to prevent vapor drive from the exterior through the foam to the sub-zero steel surface of the tank. If vapor were to pass through the SPF, it would freeze instantly upon contact with the steel and cause the SPF to delaminate, resulting in a system failure. In this project, the contractor also utilized the optional finish coat of ALDOCOAT 400 Premium Acrylic to add extra UV protection.

Maintenance

To insure continued and maximum SPF and coating performance, the owner has put in place a prudent annual maintenance program and a plan to re-coat these tanks every five years.