Performance Benefits
SCHULTZ® S740 is a vapor/liquid phase high-temperature synthetic heat transfer fluid with extremely high heat stability. It can be applied at extremely high temperatures in the vapor phase state.
Excellent Heat Stability – SCHULTZ® S740 has excellent heat stability and can provide reliable long-term operation within the temperature range of 12–400°C. It is currently the heat transfer fluid with best heat stability performance. Therefore, it is wildly used in concentrated solar power (CSP).
Vapor/Liquid Phase Use – SCHULTZ® S740 is suitable for liquid-phase heating systems with a temperature range of 12–400°C or for vapor-phase heating systems with a temperature range of 257–400°C. SCHULTZ® S740 has lower vapor pressure at high temperatures and its saturated vapor pressure in 400°C is only 1.06 MPa
Good Temperature Control Properties – When SCHULTZ® S740 is in the vapor phase, it has precise temperature control properties; it is wildly used in systems that have a high requirement of precise temperature control such as melt spinning of polyester fibers.
Low-Temperature Properties – The crystallization point of SCHULTZ® S740 is 12°C, and it has lower viscosity even when used at low temperatures. However, certain measures should be taken at low temperatures to prevent the crystallization of S740 from troubling the heating system.
Toxicity and Corrosivity – SCHULTZ® S740 includes independently developed low-sulfur and low-chloride raw additives, which can reduce the toxicity and corrosivity of the heat transfer fluid effectively.
Product Typical Properties – SCHULTZ S740 (Biphenyl and diphenyl oxide)
Appearance |
Clear transparent liquid |
Component |
Biphenyl/diphenyl oxidemixture |
Moisture Content / (mg/kg) |
114 |
Flash Point / °C |
118 |
Auto Ignition Temperature / °C |
600 |
Crystallization point / ℃ |
12 |
Density (20°C) (kg/m3) |
1063 |
Total Acidity / KOH (mg/g) |
0.01 |
Carbon Residue % |
0.01 |
Sulfur Content / (mg/kg) |
3 |
Chlorine Content / (mg/kg) |
4 |
Kinematic Viscosity (mm2 /s) 40°C |
2.5 |
Kinematic Viscosity (mm2 /s) 100°C |
0.99 |
Coefficient of Thermal Expansion (200℃) / ℃ |
0.000979 |
Volume Contraction upon Freezing / % |
6.27 |
Volume Contraction upon Melting / % |
6.69 |
Normal Boiling Point / ℃ |
257 |
Average Molecular Weight |
166 |
Surface Tension in Air (25℃) / (mN/m) |
36.6 |
Resistivity (20℃) / (Ω•cm) |
6.4×1011 |
Heat of Melting / (kJ/kg) |
97.3 |
Heat of Vaporization (400℃) / ( kJ/kg) |
206 |
Pseudocritical Temperature / ℃ |
499 |
Pseudocritical Pressure / bar |
33 |
Pseudocritical Density / (kg/m3) |
327 |
Optimal Applicable Temperature Range / ℃ Liquid |
12-400 |
Optimal Applicable Temperature Range / ℃ Vapor |
257-400 |
Maximum Operation Temperature / ℃ |
400 |
Maximum Liquid Film Temperature / ℃ |
430 |
Note: The above data are based upon test samples in laboratory, and not guaranteed for all products.
For full specifications of SCHULTZ® S740, please contact our sales dept.