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 232°C in electric and steam heaters and down to a -14°C 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 -5°C and -15°C respectively. And while glycol solutions have a maximum operating temperature of 160°C, Paratherm LR is completely stable up to it’s 232°C maximum operating temperature. Stability tests showed less than 3% degradation after 500 hours at 287°C.

Typical Properties*

Chemical Name Paraffinic hydrocarbon
Appearance Water White Liquid
Odour Odourless
Maximum Recommended Film Temperature 260°C/500°F
Maximum Recommended Operating Temperature  232°C/450°F
Minimum Operating Temperature 20 mP-s (20 cPs) -50°C/-58°F
Minimum Start-up Temperature 300 mP-s (300 cPs) -80°C/-112°F
Viscosity at 15°C mm2 /sec (cSt) 2.4
Density at 15.5°C/60°F kg/m3 (lb/gal) 766 (6.4)
Flash Point Closed Cup (D56) >54°C/130°F
Autoignition Temperature (maximum 10 sec ignition delay >260°C/500°F
Boiling Point (101 kPa/14.7 psia) 202°C/397°F
Vapour Pressure @ maximum operating temperature kPa (psia) 145 (21)
% Volume expansion over recommended operating temperature per 37°C (°F) 12.2 (6.8)
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) kJ/kg (BTU/lb) 46,300 (20,000)
Heat of vapourization (approximate) kJ/kg (BTu/lb) 262 (113)

 * 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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