Heat Transfer Fluids

For non-pressurized closed-loop thermal systems

Paratherm™ MR HTF


Paratherm™ MR Heat Transfer Fluid is a mid-range heat transfer fluid rated for service from 36°F to 550°F. It is efficient across the temperature range, thermally stable and cost-effective. Paratherm MR is NSF HT-1 certified for food-grade applications. Used or contaminated fluid can be safely combined with spent lubricating oils and recycled locally. Paratherm MR is designed for a broad variety of applications such as batch reactors, laminating lines and plastics mold temperature control. It is engineered to provide outstanding performance under demanding conditions.


Minimum Startup Temp (300cSt)Maximum Operating Temp
-37°F / -38°C580°F / 304°C


  • Premium NSF HT-1 heat transfer fluid
  • Wide operating range
  • Single fluid for multi-zone heating & cooling applications
  • Non-aromatic/low odor composition reduces worker exposure and environmental issues
  • Improved low-temperature capability vs standard mineral oil-based heat transfer fluids



Paratherm MR Heat Transfer Fluid is plant friendly and safe to use. In the event of a release, the same simple clean-up procedures used for spills of light lubricating oils can be employed. Recovered fluid can be combined with spent lube oils and sent to the local oil recycler. Paratherm MR is a high purity, water-white fluid and contains no SARA-reportable substances, such as chlorinated hydrocarbons, aromatics, heavy metals, or sulfur or nitrogen compounds.


Unlike other heat/cool liquids, the MR fluid emits no pungent or noxious odors. See the Material Safety Data Sheet (SDS) before using this product.


Paratherm MR Heat Transfer Fluid has an extraordinarily low vapor pressure — a fraction of an atmosphere at its maximum operating temperature of 550°F. This permits the designer considerable latitude in the choice of lower-cost equipment that does not need to be pressurized to prevent fluid boiling and pump cavitation.


The lower a heat transfer fluid’s viscosity, the less energy will be required to pump it through the system. Paratherm MR fluid’s viscosity is among the lowest of available heat/cool fluids. This and the fluid’s exceptionally low-pressure drop means that less horsepower is needed for a given duty and that a smaller pump and motor can be specified. And, lower power consumption continues to produce savings year after year.

Mobile users view full PDF here: MR-Bulletin_Mar2022.pdf

Mobile users view full PDF here: PARATHERM-MR-SDS.pdf

Chemical NameLinear Alkene
AppearanceWater White Liquid
OdorSlight Odor
Maximum Recommended Film Temperature 600°F/316°C
Maximum rec’d operating temp – fired heaters550°F/288°C
Maximum rec’d operating temp – all others 580°F/304°C
Minimum operating temperature 20 cPs (20 mPa-s) 38°F/3°C)
Minimum start-up temp 300 cPs (300 mPa-s) -37°F/-38°C
Viscosity @ 60°F/15.5°C sSt (mm2/sec)13
Density @ 60°F/15.5°C lb/gal (kg/m3 )6.7 (804)
Flash Point Pensky-Martens Closed Cup (D93)>300°F/149°C
Boiling Point (14.7 psia/101 kPa)>650°F/343°C
Vapor Pressure @ max operating temp psia (kPa) 8.4 (61)
% Volume expansion over rec’d operating temp per 100°F (°C)4.4 (7.9)
Average Molecular Weight300
Heat of Combustion (approximate) BTU/lb (kJ/kg)20,000 (46,300)
Heat of Vaporization (approximate) BTU/lb (kJ/kg)115 (266)

* 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.


Critical Temperature,
146514531580152413581174 1168
Critical Pressure,
Critical Volume,
cm3/g-mole8161579 72013809871327493
Heat of Vaporization,
DH vap
Molecular Weight avgMW239350445360230160133
Constants: k=Cp/Cv = 1.01 | C’ = 316.5 | R = 82.06 cm3*atm/mol*K | Fb = 1.0

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