Thermal Actuators

The versatility of thermal actuators has led to their implementation in various unique Aerospace & Defense applications. Combining straightforward design and reliable performance, our technology is often the ideal solution for particularly remote, original, and extreme design challenges.

At ThermOmegaTech®, each of our thermal actuator valves is powered by our proprietary Thermoloid® paraffin wax actuator, which is precisely blended to produce a controlled volume change and usable stroke in response to a narrow range of temperature variations.

The actuators utilize paraffin wax blends with varying melting points ranging from 20°F to 270°F (-6.6°C to 132.2°C).

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Thermal Actuators


How Thermal Actuators Work

When the thermal actuator is in its “cold position,” the Thermoloid® wax is solid, and the piston is retracted. Once the temperature increases within the valve’s pre-determined active range, the wax changes into its liquid phase, undergoing thermal expansion and increasing volume.

This expansion extends the piston, producing usable stroke and putting the actuator into its “hot position.” The piston can then act upon a valve stem, lever, or any other mechanical device requiring this type of movement.

Thermal actuators convert a temperature change into a mechanical force to push/pull, open/close, or move a load. The temperature change causes the wax to change its phase, which occurs over a narrow and customizable temperature range, typically within 10-15°F but can be modified to suit a variety of applications.

Due to the non-compressible nature of the wax, this motion produces a significant amount of force.


  • Self-Actuating: No need for an external power source
  • Maintenance-Free: No periodic calibration or service requirements
  • Predictable: Piston moves in relation to specific temperatures
  • Simplistic Design: Increases service life and minimizes part failures
  • High Power to Size and Weight Ratio: Small, light-weight designs
  • No Electric Power: Ideal for applications in explosion-proof environments



Each actuator is blended to respond to a specific temperature range and can be implemented into various heating, cooling, or control/activation applications. The piston stroke generated by the thermal actuator will depend entirely on the thermal management/control system it is integrated into because of the simplicity of the design.

Thermostatic actuators are 100% self-powered, which makes them ideal solutions for applications in explosion-proof environments. Actuators can be integrated into a wide variety of bodies, manifolds, and systems to produce motion based solely on temperature. This highly reliable technology is often used as a fail-safe in systems to guarantee an action even if electricity or other power source fails.

Temperature-activated valves have a long history of meeting the challenging demands of the Aerospace and Defense Industry. With the intrinsic accuracy of phase-change modulating valves to precisely account for gradual temperature changes, the applications for our technology are limited only by the designer’s imagination.

Thermal Actuator Control of Airflow for UAVs

Thermal Actuator Control of Bouy Release Mechanism

Thermal Actuator Control of Fuel Oil Coolers


Thermostatic wax valve actuator technology is incredibly flexible; its parameters can be molded to fit your unique temperature control project and individual vision. Our actuators have been used in applications with operating temperatures from 20°F to 270°F (-6.6°C to 132.2°C). 

In addition to our comprehensive catalog of standard products for thermal bypass, fluid temperature control, electronics cooling, airflow control, freeze protection, scald protection, and more, we offer custom-design engineering services to satisfy unique product requirements. Please inquire with our team if you require lower temperatures than our standard offering.

Schedule a Lunch & Learn consultation with ThermOmegaTech’s® product specialists and design engineers to discuss your temperature control needs.

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Past Projects

ThermOmegaTech’s thermostatic valves and actuators thermostatic technology has been implemented into dozens of unique and unprecedented Aerospace and Defense applications where accurate temperature control was critical to successful execution.

Some applications where our temperature actuated valve technology has been implemented into custom designs include hydraulic oil cooling for ground-based military equipment, electronics cooling for high-performance aircraft, thermostatic control for heat exchangers in army tanks, airflow control on UAVs, temperature control in navy radar systems, and linear heater actuator release of buoys.

Airflow Control on Unmanned Prototype Jet

Airflow Control on Unmanned Prototype Jet

Linear Heater Actuator Buoy Release

Linear Heater Actuator Buoy Release

Hydraulic Temperature Control on Tanks

Thermal Actuator for Hydraulic Temperature Control on Tanks
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