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Heat Transfer Liquids

Heat transfer liquids are generally made from one of the following: mineral oil, diphenyls, modified terphenyls or polyalkalene glycols. Heat transfer liquid is also known by a variety of trade names such as Dowtherm, Mobiltherm, Therminol, Ucon, etc.

Other Names: Heat transfer oil, HTO
Sp. Gr.: Approximately 1.0 @ pumping temperature; varies with liquid and temperature
Viscosity: Less than 1 cPs. at pumping temperatures

Remarks: Heat transfer liquids are used instead of steam for transferring heat from a source to a point of use such as dies, presses, cooking vessels, processing equipment, etc. Many of them can operate at temperatures up to 315°C / 600°F.

Pump Notes: Cast iron construction is satisfactory. Viton® elastomers are normally recommended due to heat but PTFE or Kalrez® may also be needed. Mechanical shaft seals are recommended. Because of the low viscosity, pump capacity is sometimes less than nominal. To extend the service life, it is recommended that the pumps be run at rated speed or less and that the operating pressure in the system be kept as low as possible. Heat transfer liquid pumps are often critical to the success of an extensive operation, standby pumps should be considered.

 Viton® and Kalrez® are registered trademark of DuPont Dow Elastomers®, L.L.C.