Paratherm™ LR Low Range Heat Transfer Fluid

Paratherm™ LR Low Range Heat Transfer Fluid

Single Fluid Heating and Cooling – Non Aromatic – Non Aqueous

Paratherm LR heat transfer fluid is an aliphatic-hydrocarbon based heat transfer fluid designed for use in closed-loop, liquid phase heating and cooling systems up to 450°F in electric and steam heaters and down to a -58°F surface temperature in direct-expansion exchangers. Registered HT-1 for incidental food contact by NSF

Applications include:

    • Specialty chemical batch heating and cooling
    • Pharmaceutical Production Equipment
    • Secondary Coolant (“Brine”) Systems
    • Replacing Silicone Oil? Simply drain and refill
    • Food Processing

Reduce Process Hazards when Processing Water-Sensitive Product

Many products undergo a violent exothermic reaction when exposed to water. Paratherm LR can be used safely for temperature control in these reactions because, unlike water/glycols, it’s not mixed with water. And because it contains no double bonds or bonded oxygen molecules, it’s extremely stable.

Wider Temperature Range than Glycols

Paratherm LR has higher heat-transfer coefficients than 50% ethylene-glycol and 50% propylene-glycol solutions below -22°F and -4°F respectively. And while glycol solutions have a maximum operating temperature of 320°F, Paratherm LR is completely stable up to it’s 450°F maximum operating temperature. Stability tests showed less than 3% degradation after 500 hours at 550°F.

Typical Properties*

Chemical Name Paraffinic hydrocarbon
Appearance Water White Liquid
Odor Odorless
Maximum Recommended Film Temperature 500°F/260°C
Maximum Recommended Operating Temperature  450°F/232°C
Minimum Operating Temperature 20 cPs (20 mP-s) -58°F/-50°C
Minimum Start-up Temperature 300 cPs (300 mP-s) -112°F/-80°C
Viscosity at 60°F cSt (mm2 /sec) 2.4
Density at 60°F/15.5°C lb/gal (kg/m3 ) 6.4 (766)
Flash Point Closed Cup (D56) >130°F/54°C
Autoignition Temperature (maximum 10 sec ignition delay >500°F/260°C
Boiling Point (14.7 psia/101 kPa) 397°F/202°C
Vapor Pressure @ maximum operating temperature psia (kPa) 21 (145)
% Volume expansion over recommended operating temperature per 100°F (°C)  6.8 (12.2)
Average Molecular Weight 160
Dielectric Breakdown voltage D1816-04 (kV, 0.1″ gap) 22.15
Dielectric Constant (1 KHz) D924-04 2.03
Dissipation Factor (1 KHz) D924-04 0.00001
Volume Resistivity at 100V (?-cm) D257-07 1.84X1014
Heat of combustion (approximate) BTU/lb (kJ/kg) 20,000 (46,300)
Heat of vaporization (approximate) BTu/lb (kJ/kg) 113 (262)

 * These are typical laboratory values, and are not guaranteed for all samples.  ** Note: Normal practice is to size expansion tanks so that they are 1/4 to 1/3 full when the system is cold, and 2/3 to 3/4 full when the system is at the maximum normal operating temperature.

Paratherm LR™ vs. Ethylene Glycol and Propylene- Glycol Solutions — Comparison of Heat Transfer Coefficients

Physical Properties

Paratherm LR
  Propylene Glycol**   Ethylene Glycol**
Temp*   Density* ThermalConduct.* Viscosity* Spec.Heat   Dens. Therm.Cond. Visc. Spec.Heat   Dens Therm.Cond. Visc Spec.Heat
50   6.4 0.088 2.1 0.47   8.9 0.206 10.7 0.80   9.1 0.215 5.5 0.74
-4   6.6 0.090 5.0 0.44   9.0 0.193 73.0 0.77   9.2 0.199 22.1 0.71
-22   6.7 0.090 7.3 0.43   9.0 0.188 172.8 0.76   9.3 0.193 44.0 0.70
    *Density, lb/gal*Thermal Conductivity,        BTU/(hr- ft²-°F/ft)*Viscosity, cP*Specific Heat, Btu/(lb-°F)


*Temperature, ºF

  **All data pertaining to Propylene and Ethylene glycol was obtained from Dow literature for the Dowfrost HD and Dowtherm 4000 @ 50% by Volume respectively    

Fluid Film Coefficient – hi***

  Temp   Paratherm LR Propylene Glycol Ethylene Glycol
  50   157 199 277
  -4   106 77 137
  -22   89 51 97
Based on 3/4″ Sch. 40 pipe @ 4’/sec.***hi, BTU/(hr-ft²-°F)


  • At 50°F, glycol solutions have higher coefficients
  • At -4°F, LR has a higher coefficient than Propylene Glycol solution
  • At -22°F, LR has almost the same coefficient as Ethylene Glycol solution

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