Heat transfer fluids

On order
Eni Alaria 2
Mineral heat transfer fluid, to 270 °C in closed systems
ISO 6743/12 QB
On order
Eni Alaria 3
Mineral heat transfer fluid, to 300 °C in closed systems
ISO 6743/12 QB
On order
Eni Alaria 3 HT
Mineral heat transfer fluid, to 320 °C in closed systems
ISO 6743/12 QC
On order
Eni Alaria 7
Mineral heat transfer fluid, to 270 °C in closed systems
ISO 6743/12 QB
On order
Mobiltherm 603
Mineral heat transfer oil for closed systems to 285 °C, or open systems to 150 °C
On order
Mobiltherm 605
Mineral heat transfer oil for closed systems to 315 °C, or open systems to 180 °C
DIN 51522 Q
On order
Mobiltherm 610
Mineral heat transfer oil for closed systems to 315 °C, or open systems to 250 °C
On order
Mobiltherm 611
Mineral heat transfer oil for closed systems to 315 °C, or open systems to 275 °C
On order
Shell Heat Transfer Oil S2
Mineral oil for closed-loop heat transfer circuits
Temperatura maxima a filmului : 330ºC
On order
Shell Heat Transfer Oil S2 S
Mineral oil for closed-loop heat transfer circuits
Temperatura maxima a filmului : 320ºC

A fluid that lubricates nothing

Heat transfer fluid is the only product in the catalogue whose job has nothing to do with friction: it carries heat from source to consumer in a closed circuit, at temperatures where an ordinary oil would break down within days. What matters is thermal conductivity, specific heat, viscosity at pumping temperature and, above all, thermal stability. Degradation takes two forms with opposite effects: cracking produces light fractions that lower the flash point and can pressurise the expansion vessel, while polymerisation produces heavy fractions that deposit on the coil walls and insulate exactly the surface heat has to cross. A circuit left to degrade does not fail suddenly — it loses efficiency for months, then blocks.

Types and temperature limits

Highly refined mineral oils cover duties up to roughly 300–320 °C in the liquid phase and are the usual choice in food processing, woodworking, textiles and presses. Synthetic fluids — aromatic hydrocarbon or ester based — go higher and tolerate repeated thermal cycling better, at a higher initial cost. The classification reference is DIN 51522, and in service the film temperature (not the bulk temperature, which is always lower) matters as much as the minimum flow rate that keeps the flow turbulent. In a food or pharmaceutical circuit where incidental contact is possible, the equivalent is an NSF HT1 registered fluid.

What to monitor in a thermal circuit

An annual analysis costs far less than a blocked coil:

Flash point: a falling value indicates thermal cracking and is the first sign that film temperature is too high.
Viscosity: a rising value indicates polymerisation, and deposits on the heat-transfer surfaces follow.
Acid number, as a measure of oxidation — a circuit drawing air through an open expansion vessel shows it first.
Flow rate, not only temperature. Below minimum flow the regime goes laminar, the film at the wall overheats and the fluid degrades locally even while the thermometer looks fine.
Do not top up with a different fluid type. A mineral-synthetic mix can end up less stable than either component.