Industrial / Energy Fluids

Xceltherm® DE

XCELTHERM® DE is engineered for applications where thermal and electrical performance must work together. With a maximum bulk operating temperature of 626°F (330°C), a pour point below -85°F, and a dielectric breakdown voltage of 70 kV, DE delivers reliable performance across a wide operating range. Its benzyltoluene/diphenylethane formulation provides excellent thermal stability and low viscosity — making it a high-integrity choice for demanding dielectric heat transfer applications.

Typical Properties

Key Operating Temperatures
Maximum Bulk Operating Temperature 330°C 626°F
Maximum Film Temperature 358°C 676°F
Pour Point (ASTM D97) ≤ -60°C < -85°F
Flash Point by Cleveland Open Cup (ASTM D92) 136°C 277°F
Fire Point by Cleveland Open Cup (ASTM D92) 150°C 302°F
Autoignition Temperature (ASTM E659) 464°C 867°F
Pumpability at 300 cSt -55°C -67°F
Normal Boiling Point ≥ 270°C ≥ 518°F
Physical Properties
Appearance Clear, colorless to straw yellow liquid
Odor Aromatic
Color (ASTM D2129), APHA ≤ 70
Composition 35 to 45% Benzyltoluene
55 to 65% Diphenylethane
Epoxide concentration, mg HCl/g 1.9
Ethyl vanillin content, ppm 0
Kinematic Viscosity, mm²/s (cSt) (ASTM D445)
at 20°C (68°F)
at 40°C (104°F)
at 100°C (212°F)
 

4.27
2.65
1.07

Average Molecular Weight, g/mol 182
Moisture Content, parts per million, maximum 300
Density at 25°C (77°F) (ASTM D1298) 980 kg/m³
Specific Gravity at 20°C (ASTM D1298) 0.99
Coefficient of Thermal Expansion 20 – 100°C (ASTM D1903) 5.3 x 10⁴
Dielectric Constant at 20°C (68°F) 2.5
Dielectric Breakdown Voltage, kV (IEC 156) 70
Dissipation Factor, 50 Hz at 90°C (IEC 247) 0.001
Gas solubility at 25°C (ASTM D2495)
O₂
N₂
1.9%
3.7%
Permittivity
at 25°C (IEC 247)
at 100°C (ASTM D924)
2.4
2.40 – 2.52
Refractive Index 1.566 – 1.5794
Surface Tension at 80°C (ASTM D3825, dynes/cm) 38.24
Volume Resistivity at 90°C (IEC 247) 1.0 x 10¹⁵
Vapor Pressure
at 20°C
at 100°C
0.004 kPa   0.00058 psia
0.133 kPa   0.019 psia
Water Solubility at 20°C Immiscible
Water Content (ASTM D6304), ppm ≤ 70
Acid Number, mg∙KOH/g < 0.01