Three different grades of foam tanks are available, minimum foam, medium foam, maximum foam and customer thickness requirement up to 50 mm, the maximum give 3-4 mm more in sandwich than the normal solid PE tanks, without foam the difference between them lies in the extent of foam expansion (foam ratio) or thickness of the foam products. As the thickness of the foam increases the thermal conductivity decreases. The density of the result tank foam will also vary, with the foam of maximum expansion having a large cell size (more air in the foam structure), and therefore lower density.

The thermal conducting of PE is reduced by using foam. Hence the heat transfer will be less and this is important properties when using foam tanks to reduce the heat transfer between cold water and the surroundings. The insulated tanks are available for all sizes.

PE Foam increases rigidity and stiffness of molded tanks. As well as increased strength advantages imparted upon tank by the use of foam instead of solid PE, the insulating properties of foam may have useful application.