Description
Thermaflo® 660 is a recycled, high-performance synthetic heat transfer fluid based on partially hydrogenated terphenyl chemistry—the same proven molecular platform that has dominated high-temperature industrial heat transfer for decades. This fluid combines the inherent thermal stability of polyphenyl ring structures with strategic hydrogenation to optimize viscosity and low-temperature handling characteristics. The partially hydrogenated terphenyl composition consists of selectively saturated mixtures of terphenyls and quaterphenyls (three and four hybridized benzene rings), delivering exceptional resistance to thermal degradation at sustained high temperatures while maintaining pumpability in cold-start conditions. With an operating range from 0°C to 345°C (32°F to 653°F) and a maximum film temperature of 370°C (689°F), Thermaflo® 660 offers true high-temperature performance in non-pressurized, liquid-phase systems—providing a cost-effective recycled alternative without compromising on thermal stability or service life.
- Industry-Leading High-Temperature Stability: Operates continuously at 345°C (650°F) bulk temperature with minimal degradation, matching the performance standard set by premium hydrogenated terphenyl fluids.
- Exceptional Fouling Resistance: Molecular structure is engineered to minimize formation of both low boilers (volatile degradation products) and insoluble high boilers, keeping heat transfer surfaces clean and efficient.
- Low-Pressure System Design: Vapor pressure of only 6 psi at 316°C (600°F) enables use in conventional non-pressurized or low-pressure indirect heating systems, reducing equipment complexity.
- Cold-Weather Pumpability: Freeze point below -33°C (-27°F) with pumpability to 5°C (41°F) ensures reliable system startup even in cold ambient conditions.
Applications
Polyester & PET Production · Nylon & Synthetic Fiber Manufacturing · Polymerization & Polycondensation · Chemical Processing · Oil & Gas Refining · Plastics & Polymer Extrusion · Reactor Heating · Distillation Columns · Biodiesel Production · Asphalt Processing · Organic Silicon Production · Heat Recovery Systems · Food Processing Equipment · Pharmaceutical Manufacturing · Industrial Dryers · Coal Chemical Processing
Benefits
Superior Thermal Stability · Fouling-Resistant Chemistry · Extended Service Life · Low-Pressure Operation · Cold-Start Capability · Recycled & Cost-Effective · Direct Compatibility with Hydrogenated Terphenyl Systems · Proven Performance Record
Product Availability
5 Gal (20 kg) · 55 Gal Drum (220 kg) · Bulk (Totes / Tankers)
Product Data
| Property | Specification |
| Appearance | Colorless to Pale Yellow |
| Composition | Partially Hydrogenated Terphenyl |
| Moisture Content (ppm) | <200 |
| Flash Point, COC | 374°F (190°C) |
| Autoignition Temperature (ASTM D-2155) | 716°F (380°C) |
| Kinematic Viscosity @ 40°C (cSt) | 30 |
| Kinematic Viscosity @ 100°C (cSt) | 3.9 |
| Density @ 20°C (lbs/gal) | 8.32 |
| Specific Gravity @ 20°C | 1.012 |
| Freeze Point | <-27°F (<-33°C) |
| Pumpability Limit (KV=400 cSt) | 41°F (5°C) |
| Boiling Range @ 760 mmHg | 637°F–662°F (336°C–350°C) |
| Bulk Temperature Range | 32°F–653°F (0°C–345°C) |
| Maximum Film Temperature | 689°F (370°C) |
| Total Acid Number (Max) | <0.05 mg KOH/g |
| Thermal Conductivity (@ 600°F / 316°C) | 0.0535 BTU/ft/hr |
| Vapor Pressure (@ 600°F / 316°C) | 6 psi |
| Average Molecular Mass | 252 |


