Senior Aerospace Metal Bellows

Thermal Actuators and Control Valves

Thermal Actuator Click to view larger image

Senior Aerospace designs and manufactures thermal actuators and thermal valves.  These devices are designed to actuate as a function of external temperature.  These are passive, automatic devices requiring no electrical power.  The thermal actuator element is driven by an expansion media (wax or fluid) that will change volumetrically with changes in temperature.

Higher Reliability, Higher Temperature Operation

Senior’s thermal actuators and thermal valves are differentiated from conventional devices by our use of our welded metal bellows technology.

A conventional device will use a rubber membrane to encapsulate the expansion media. The problem with this approach is that the rubber is a wearing item so these devices are cycle life limited. The rubber is temperature limited so these devices are not suitable for higher temperature applications. Over time the rubber will allow the expansion media to leak so the device will see performance drift over time and then eventual failure.

Senior uses our welded metal bellows to encapsulate the expansion media. Because we eliminate elastomers, the all-metal construction is capable of operation at significantly higher temperatures than conventional devices and can also withstand cold soak conditions that are detrimental to rubber. Further, the welded metal bellows is capable of 1,000,000+ thermal cycles offering reliability that is orders of magnitude greater than conventional devices. Because the bellows construction means zero leakage of the expansion media, the Senior thermal actuator experiences NO performance drift over time.


Design and Operation

The thermal actuator and thermal valve can be designed to operate at a wide range of temperatures. The expansion media is tuned for a specific actuation temperature range. These devices provide precise movement for a specified temperature range. Presently Senior has thermal actuator and thermal valve solutions for actuation temperature ranges to 600°F.

Thermal valves may also incorporate an integrated pressure relief function. The pressure relief mechanism is factory calibrated to lift off of the valve seat at the specified “relief” temperature and pressure. The pressure relief mechanism uses a “tuned” spring that is factory set and never needs readjustment.

Senior Aerospace Metal Bellows can also design other
Custom Products to meet your application. If you don’t see
a product that meets your specific requirements,
we look forward to providing you with a “Solution”.

Thermal Valve Features

  • All metal construction no elastomers
  • Temperature sensitive expansion media is contained in a hermetically sealed vessel with a welded metal bellows as the flexible pressure boundary
  • Welded metal bellows allows for volumetric change of expansion media
  • Designs may be tuned for specific temperature ranges
  • May be designed with integrated pressure relief
Detail info and technical specifications on products, capabilities and systems
If you have a thermal actuator or a thermal valve requirement click here to submit a thermal valve design data sheet.
Thermal Actuator
Click to view larger image
Thermal Actuator
Click to view larger image

Thermal Valve Benefits

  • Zero leakage - no expansion media loss
  • No lubricants - all pressure generated work produces useful work
  • No degradation in performance over time
  • No lubricants are required
  • Actuation temperature ranges to 600F
  • Impervious to cold soak conditions
  • Thermal cycles to 1,000,000 or greater

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