Industrial Heat Transfer Oil

Performance Standard: 

  • High heat transfer co-efficients
  • High thermal & oxidation stability
  • Good viscosity & temperature characteristic
  • Low vapor pressure & toxicity
  • Non-corrosive

Oil Life

Life of Byco OTX depends on design and usage of system. If system is well designed and not subjected to abnormal work loads/shutdown the life of the oil can be enjoyed for long period. However, oil condition monitoring at regular interval is important to measure the change in physical characteristics of the oil.


Thermal Stability:

  • Mineral oil are subject to degradation at high temperature.
  • Cracking of hydrocarbon molecules by heat some of that appears as volatile gases and polymerize into non-soluble deposits.
  • Oxidation of hydrocarbon oil with atmospheric oxygen that increases rapidly with increasing temperature.
  • Oxidation produces acidity in oil with some non-soluble contaminants that result in increase in viscosity.

Byco OTX is developed to display exceptionally good thermal stability at temperatures upto 320°C depending on the ISO VG Grades. The low rate of cracking and oxidation gives maximum oil life assuming efficient fluid heater with good pump circulation.

Equipment Design and Operating Advice:

The potential source of damage to Byco OTX is the heater. To avoid damage, circulation pump should be capable of producing high turbulent oil flow through the heater. Heat flux should be kept to a minimum to reduce film temperature.


Mineral Oil for all closed fluid heat transfer systems.

Key Properties

ISO VG Grade 22 32 46 Test Method
Auto ignition Temperature, °C 330 350 360 -
Flash Point, COC, °C 209 230 235 ASTM D-92
Pour Point, °C -12 -12 -9 ASTM D-97
Viscosity, mm²/s@ 40°C 22 32 46 ASTM D-445
Viscosity Index 102 102 98 ASTM D-2270
Maximum Bulk Film Temp, °C. 290 320 325 -
Coefficient of Thermal Expansion per °C 0.000076 0.00077 0.00078 -
Physical & Thermal Properties of ISO VG 32 versus Temperature
100°C 200°C 300°C -
Density, kg/L 0.82 0.76 0.69 -
Dynamic Viscosity, mPa.s 4.35 1.05 0.46 -
Specific Heat Kj / kg.°Cs 2.15 2.15 2.88 -
Thermal Conductivity, W/m.°C 0.128 0.120 0.112 -
Vapor Pressure, mmHg - 3.5 150 -

Note: The typical characteristics are given as a guide only and may vary according to latest production according to ISO.