Bulk storage diesel tanks are no choice but to have them set out in the elements. If traditionally insulated, it is very likely that moisture will make its way into the insulation and on the surface of these tanks. Diesel tanks that hold product over 320°F (160°C) may seem to be resistant to CUI owing to the higher temperatures, however, that temperature is only up to the fill line. Areas above the fill line that does not reach the higher temperatures will be subject to corrosion.
All of the different types of thermal insulation have their strengths and weaknesses. Though thermal insulating coatings have not been around as long as more conventional forms of insulation, it has become fairly obvious where they are and are not successful. The benefits yielded on the fruitful applications make believers out of the most resistant skeptics. By using insulating coatings in their comfort zone, you are ensuring a sustainable system that will serve as a return on your investment well before any maintenance concerns arise.
In colder climates, applications must be thoroughly scrutinized. The combination of freezing temperatures and wind load does not bode well for a thin film coating. Though they can still adhere to the surface at low temperatures, their performance value can be decreased. Where 60 mil (1.5mm) may be sufficient in the Gulf Coast of the United States, an application may require 180 mils (4.5mm) in a climate similar to the Netherlands. Or, depending on the application, an insulating coating may not be recommended at all. It may be in their best interests to apply the coating only to the roof of the tank, while the sidewalls remain conventionally insulated because higher surface temperatures (+320°F, +160°C) keep corrosion from being an issue, or a certain thermal performance value may be required. Regardless, there must always be a heat source. Freeze protection application is usually not recommended for insulating coatings.
Insulating coatings can easily be used for personnel protection on storage diesel tanks. The coating can only be applied to areas that are vulnerable to being touched by personnel. It is not necessary to coat any additional areas, so the amount of material needed can be very low. Conventional insulation requires custom fabrication when trying to insulate next to stairways, or really anything further the sides of the tank. In an application in Pasadena, TX, one company chose to only insulate along the stair well and the bottom 7 feet of the tank. Also, if these areas were conventionally insulated, the promotion of corrosion in the smaller areas can still warrant the replacement of the insulation, or even the entire tank, in the future.