Equivalent to Therminol - 55

Diphyl-DT Heat Transfer Fluid

Product Overview

Diphyl® DT is a mixture of isomeric ditolyl ethers (dimethyl diphenyloxides). It boils in the temperature range between 284 and 294°C at 1.013 bar. Under pressure it can be operated in the liquid phase up to a temperature 330°C. With a pour point of -54°C, Diphyl® DT Heat Transfer Fluid can be operated even at temperatures as low as -30°C. The auto ignition temperature is 545°C, The typical inherent odour of Diphyl® DT Heat Transfer Fluid enables leaks to be identified quickly. The level of production related impurities, such as chlorine and sulphur compounds, is so low that corrosive damage caused by the HTF is unlikely.

Characteristic Data

Parameter Unit Value
Appearance Clear, pale yellow liquid
Odour Inherent odour
Ditolyl ether content weight-% min. 97.5
Pour point °C -54
Boiling range °C 284-294
Flash point °C 135
Autoignition temperature °C 545
Maximum film temperature °C 340
Density (20°C) kg/m³ 1035
Kinematic viscosity (20°C) mm²/s 6.3
Surface tension(20°C) mN/m 37
Thermal conductivity (20°C) W/m.K 0.134
Mean specific heat (20°C) kJ/kg.K 1.58
Net caloric value HU MJ/kg 37.6
Coeff. of therm. expansion (-20 to 300°C) K⁻¹ 10.6 × 10⁻⁴


Why Choose Prisco Chem


To be a reliable supplier by providing innovative products in service solutions.


To be a Leader in Heat Transfer Fluids (HTF) Business and grow our portfolio of speciality chemicals.


To provide customers with top quality products and services in a most responsible manner.

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Diphyl DT is a mixture of isomeric ditolyl ethers known for its excellent heat transfer properties. Boiling in the temperature range of 284 to 294 °C at 1.013 bar, it is suitable for various applications. This broad boiling range makes it adaptable to diverse heat transfer systems, offering flexibility in temperature management.

Yes, Diphyl DT Heat Transfer Fluid can be operated under pressure, particularly in the liquid phase, with a temperature capability extending up to 330 °C. This feature enhances its versatility, allowing for efficient heat transfer in both standard and pressurized systems.

Diphyl DT Heat Transfer Fluid stands out for its low viscosity, even at low temperatures. With a pour point of -54 °C, it remains operational down to -30 °C. This characteristic ensures smooth operation in colder environments, making Dipjhyl DT Heat Transfer Fluid suitable for a wide range of applications.

Diphyl DT Heat Transfer Fluid possesses an autoignition temperature of 545 °C, categorizing it as T1 temperature class. This classification highlights its high resistance to spontaneous combustion, enhancing safety during operation. Additionally, its unique properties prevent damage to devices and pipelines during the transition from a liquid to a solid state.

The distinctive natural scent of Diphyl DT Heat Transfer Fluid serves as a quick identifier for potential leaks, enabling prompt detection and mitigation. Moreover, the low levels of production-related impurities, such as chlorine and sulfur compounds, minimize the risk of corrosive damage. This ensures the long-term integrity of the heat transfer fluid and the systems it operates in.


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