Review of expanded aluminum products for explosion suppression in containers holding flammable liquids and gases

For over three decades, products made from expanded aluminum have been available for explosion suppression in fuel tanks and containers. You can find various products on the internet with names like Explosafe, Deto-Stop, Ex-Co or Explo Control, No-Ex, EM2, and others. It appears that Explosafe was the first product to appear in the late 1970s.The expanded aluminum consists of thin aluminum foil that is sliced, stretched and stacked or rolled to produce a highly porous matrix of low-density expanded aluminum. This matrix can be inserted into a fuel tank and it only takes up 1–3% of the tank volume. The matrix has been shown to dramatically reduce overpressures generated by ignition of fuel–air mixtures in a closed space if the closed space is nearly 100% filled with the matrix. The matrix has also been promoted as having other beneficial properties that reduce slosh pressures in dropped fuel tanks, suppression of algae growth, enhanced discharge of static electricity, corrosion protection for steel fuel tanks, and some state it reduces the risk of a BLEVE (boiling liquid expanding vapor explosion) in pressure liquefied gas tanks and pressure vessels.This paper reviews the history of some of these products and presents a summary of the testing that has been performed to prove some of the benefits. It also includes some limited installation experience that shows some of the penalties associated with the products.