PURUS® Heat Transfer Oil is a premium oil formulated from high quality paraffinic petroleum base oil to  meet the demanding requirements of heat transfer circulating systems. This oil is ashless and non corrosive which result in extended service life both for the fluid and equipment. PURUS® Heat Transfer Oil  has excellent thermal stability and exceptional oxidation resistance at sustained operating 
temperatures up to 500°F (260°C). The maximum recommended open system temperature is 400°F  (204°C) and the maximum closed system temperature of 600°F (316°C), works well for asphalt users.