Dyna Therm heat transfer oils should not be mixed with other oils since this may impair the excellent thermal and oxidation stability resulting in a change in other properties, and complicate analyses aimed at determining useful oil life. If the oils are used above their recommended maximum temperatures, vapor lock may result unless the system is designed to operate at the higher temperature by pressurizing with an inert gas such as nitrogen. At higher temperatures, fluid life will be shortened because the rate of thermal degradation which increases markedly as temperatures rise above the recommended limit.
As with other mineral oils, Dyna Therm heat transfer oils should be used only in systems with forced circulation. Systems that depend on convection for circulation of the heat transfer medium do not provide a rapid enough flow to prevent local overheating and rapid deterioration of the oil. Further, these oils are not recommended for use in open systems where hot oil is exposed directly to the air. If they spray or escape from leakage points, hot Dyna Therm oils may spontaneously ignite.
Dyna Therm series can be used in closed installations where the bulk oil temperature ranges are as outlined in the table below.
- Dyna Therm 22: Closed Systems (-15º C to 285º C), Open Systems (-15º C7 C to 150º C)
- Dyna Therm 32: Closed Systems (-12º C to 315º C), Open Systems (-12º C to 180º C)