Calumet produces both Type I and Type II transformer oils from our Princeton refinery. We also produce negative gassing transformer oils in Type I and II grades (see Caltran N60 oils). These oils meet the requirements of ASTM D3487 and NEMA Specifications. Calumet stays at the forefront of transformer oil technology with regular participation in the Doble Annual Survey of Electrical Insulating Oils and ASTM D27 Committee on Electrical Insulating Oils.