Shell Heat Transfer Oil S2 is resistant to oil breakage, oxidation and thickening and is based on a carefully selected, highly refined mineral oil. Effective fluid heating and proper pump circulation are maintained, which extends the life of the oil as long as the film temperature on the heater surface does not exceed acceptable limits. System usage and design affect the life of the Shell Heat Transfer Oil S2. If the system is properly designed and not overstressed, it can significantly extend the life of the system. Shell heat transfer oil S2 is highly soluble and non-corrosive, which helps keep oxidation products in solution and prevent scale formation.