A properly designed thermal oil system must have an expansion tank sized to accommodate the thermal expansion volume of the oil in the system. When selecting an expansion tank, all relevant parameters must be considered, including the total oil volume in the system (including the initial oil fill in the expansion tank), the operating temperature and the thermal expansion coefficient of the fluid.
Because different thermal oils expand at different rates, the expansion tank capacity must always be matched to the specific oil before it is charged into the system.
The expansion tank must be able to hold 20% of the total oil volume in the piping system.
The expansion tank must be installed at least 1 m above the highest point of the system, typically at a height of around 8 m.
The expansion and deaeration tank removes air and gases from the system, ensuring accurate instrument readings, preventing pump cavitation and maintaining continuous oil flow. This keeps the film temperature at the heating surfaces low, preventing oil overheating and oxidation and extending the service life of the thermal oil.
The expansion and deaeration tank manufactured by Enthalpy is a 2-in-1 unit, serving both for oil expansion and for deaeration. A special advantage of the Enthalpy expansion and deaeration tank is that it compensates for oil expansion and makes up for oil losses without mixing the cold oil in the expansion tank with the hot oil circulating in the operating system (cold oil seal). This keeps the oil in the expansion tank at a low temperature, reduces heat loss and extends the service life of the thermal oil.