Sievers Poly Tanks, LLC offers Sulfuric Acid Storage Tanks for Sulfuric Acid in concentrations of 75% to 99% made from High Density Polyethylene (HDPE). We recommend using a tank rated for at least 1.9 specific gravity. Fittings should either be welded-in polyethylene flanges or couplings; or, CPVC threaded fittings with Viton Gaskets. When storing high concentration Sulfuric Acid in a polyethylene tank, a key aspect to consider is the temperature of the liquid. If water is introduced to the acid, heat will be generated that may exceed the maximum continuous use temperature of the tank. Polyethylene tanks are great for storing Sulfuric Acid but should not be used for mixing or diluting the acid.