MultiTherm OG-1®

Oxidation Resistant Heat Transfer Fluid for Open-Loop System

MultiTherm® offers the next generation of heat transfer fluid for open-loop heat transfer fluid systems.

MultiTherm OG-1® is a hydrocracked base oil combined with the latest proprietary oxidation inhibitor/stabilizer. MultiTherm OG-1® was designed to meet the rising and demanding requirements of liquid phase open-loop heat transfer fluid system applications.

The most common form of contamination is oxidation of the heat transfer fluid. Excessive oxidation can create solids and high viscosity compounds that impair system effectiveness. Oxidation and fluid boil-off are major problems when using organic heat transfer fluids in an open-loop systems. Oxidation produces organic acids, which can polymerize and create deposits.

Open Systems
MultiTherm OG-1® is designed for use in liquid-phase heat transfer fluid systems, which are “open” to the atmosphere or there is a possibility that the heat transfer fluid in the expansion tank will come in contact with air. To reduce the oxidation process in an open-loop system, MultiTherm OG-1® is enhanced with special oxidation inhibitors to prevent this oxidative degradation and deposits.

MultiTherm OG-1® heat transfer fluid is designed for a maximum film temperature of 600°F / 316°C and a maximum system bulk temperature of 550°F / 290°C.

MultiTherm OG-1 Physical Characteristics*
Chemical Type White Mineral Oil
Appearance Clear, Liquid, Colorless
Odor None
Pour Point, ASTM D97 -44°F / -42°C
Density @ 60°F/16°C

7.19 lb/gal
.8624 g/ml

Flash Point, COC, ASTM 92 455°F / 235°C
Fire Point, COC, ASTM 92 520°F / 271°C
Autoignition Point 675°F / 357°C
Atmospheric Boiling Point (10%) ASTM D1160 704°F / 373°C
Maximum Film Temperature 600°F / 316°C
Maximum Recommended Bulk Temperature 550°F / 290°C
Average Molecular Weight 394
Neutralization Value 0.0
Pumpability Temperature @ 2000cP -4°F / -20°C
Heat of Vaporization @ 600°F / 316°C 420 BTU/lb
977 kJ/kg
Heat of Combustion 18,900 BTU/lb
43.9 MJ/kg
Coefficient of Thermal Expansion 0.00056/°F

*Typical Properties, not specifications

Low Vapor Pressure
MultiTherm OG-1® heat transfer fluid has a very low vapor pressure. This is important because fluid boil-off is an issue in open-loop systems. The rate of boil-off of a heat transfer fluid is dependent on the fluid vapor pressure. The higher the vapor pressure, the greater the rate of fluid boil-off.

High Flash Point
MultiTherm OG-1® offers the benefit of having a high flash point of 455°F / 235°C. It also offers the extra benefit of having a higher Fire Point then most other heat transfer fluids. MultiTherm OG-1® has a Fire Point of 520°F / 271°C. Benefits of MultiTherm OG-1®:

  • System heat transfer characteristics last longer due to improved oxidation resistance
  • Excellent Thermal Conductivity at high temperatures
  • Thermal Stability from improved oxidation resistance reduces efficiency robbing components such as coke deposits and particulate build-up
  • Longer oil life means less maintenance, process downtime, less oil disposal, and reduced environmental waste


Warranty: MultiTherm® warrants that MultiTherm OG-1® conforms to the data set forth in this brochure. We present this information in good faith, but because we cannot control or anticipate the many different conditions under which our information and product may be used, no other warranty, expressed or implied, is given.