Don’t be fooled by all the claims for insulation on asphalt tanks used in the HMA industry. Here are some facts to help you better understand insulation properties. Focus on Figure 1. It contains important keys to understanding the issues.

Two types of insulation are commonly used on asphalt storage tanks. They are fiberglass blanket and mineral wool blanket. Both materials are equally effective in reducing heat loss from liquid asphalt stored inside storage tanks at 300 degrees F. This assumes both types of insulation have the same thickness and are properly installed.

Importance of thickness
Increasing insulation thickness increases its effectiveness and reduces heat loss. Thicker insulation is especially cost effective up to about 6 inches (see Figure 2). So, it pays to have insulation 6 inches thick rather than anything less.

Unfortunately, certain tank sales representatives have misinformed equipment buyers about insulation. They claim that the 3 inches of insulation on their tanks have insulating properties equal to 6 inches of insulation on Heatec tanks.

This is simply not true. That claim does not stand up to an examination of information published by highly reputable manufacturers of insulation, including the manufacturer of the very insulation they use.

Sorting out the facts
It should be noted that data sheets published by insulation manufacturers are intended mainly for engineers experienced in heat transfer. Inexperienced persons may find these sheets difficult to understand and a bit confusing. So, to make sure we correctly understand the data sheets published by the manufacturer of the insulation we use, we consulted with Bill Tolliver, Product Technical Leader with Owens Corning. We also consulted with our own top engineer. The main source for our explanations and definitions is the Thermal Insulation Handbook by Turner and Malloy. To calculate heat loss we used NAIMA 3E Plus 3.2 computer program from North American Insulation Manufacturers Association.