This standard covers composition and property recommendations for fluoroelastomer belts. Terpolymer fluoroelastomers have been used for Flue Duct expansion joints due to their outstanding resistance to chemicals, oils and heat compared to any other elastomer. Fluoroelastomers are especially effective in Flue Duct applications where condensation and sulfuric acid is a problem such as in coal fired power plants. ©2015, 4 Pages.