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Machine Oil Coolers

Machine oil coolers to efficiently cool your circuits

Machine oil cooling systems span from self-contained units for supplying lubrication to individual bearings to a centralised unit providing cooling for a whole plant. As a result, the cooler ranges in size from a small vertically mounted unit to a set of parallel bay air blast oil coolers.

What to expect from Sterling Thermal Technology

  • Bespoke – We can create an optimised design for your application with features appropriate to the system requirements. The mechanical design will be based on system pressures and temperatures while the thermal design will take into account the potential use of heat transfer enhancement features.

  • Design optimisation – We create a bundle with tube-side turbulation. The fin array can be enhanced with louvres. As a result, the tube-side coefficient is maximised for available pressure loss while the fin geometry is matched to fan performance requirements and noise limitations. 

  • Flexible batch production – We produce the bespoke design as a single item or a batch run with full control, including a drawing production and approval cycle. Our fin production tooling catalogue is extensive.

How machines oil coolers work

The oil used to cool machinery is selected based on its viscosity in the anticipated operating temperature range in addition to other lubrication characteristics. The viscosity is crucial in the thermal design as it is a determining factor in the calculation of tube-side heat transfer rate.

In systems with low velocity and high viscosity, heat transfer enters the lamina regime where heat transfer coefficients are low. We can adopt two alternative design approaches:

  • Increase passes and thereby increase velocity to maintain turbulent flow, and with it, higher coefficients.
  • Introduce turbulators to ensure enhanced flow characteristics.

The limitation of these approaches is the available tube-side pressure drop. However, there is significant flexibility in the specification of turbulators. Dense windings have high enhancement factors and high-pressure drop per unit length. If pressure limits are exceeded, we can reduce the winding density to bring the design within available pressure drop limits.

Airside characteristics depend on the type of fan permitted in the environment. For safe areas, non-corrosive environments, plate mounted fans are an economical option. But, where corrosive or hazardous areas are indicated, we have broad experience in fan selection and specification.


As a recognised manufacturer of machine oil coolers, we can help you to get the best equipment for your application.

If you feel you need another type of heat exchanger, visit our products and services page or contact us.

Customised heat exchangers

Over 100 years of design & manufacturing knowledge

Your partner for the entire lifecycle of your business

Sterling Thermal Technology has designed a set of machine oil coolers that we used to cool our generator bearings. The specifications allowed for running at either 50Hz or 60Hz. The support structure of the units was mounted to our packaged skid. STT was very helpful in this collaborative effort.

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We customise our heat exchange solution to meet your requirements, so contact us today to discover the right equipment for you.

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