Thermal Actuator

Senior Aerospace Metal Bellows’ Thermal Actuators are used on aircraft engine fuel-oil heat exchangers. Senior Aerospace solved a reliability problem with the rubber boot design by replacing it with metal bellows.Traditionally, in this design, the temperature probe contained a rubber boot that encapsulated wax. As the wax heated or cooled, it would change phase and thus expanded or contracted driving the pin in or out, which actuated a bypass valve.The rubber deteriorated, which allowed the wax to leak, adversely affecting performance and ultimately failing altogether. This unit had a very high failure rate.
With this new technology, Senior’s Thermal Actuators last 10 years or greater with no performance issues.