Temperature Control Element Bellow TWB

Building / industrial services, faucets, air conditioning devices, solar systems,
food and beverage industry, radiator thermosts (fixed head, remote sensors, remote and central regulators), gas switches, discharge safety devices, industrial water mixers, hot water boilers.

Technical Design:

Temperature based volume expansion of the charge, results in a displacement of the bellow. This can be used as a constant control or as switching function in connection with electronic or electro-mechanical components.  In many cases it is used as a direct mechanical actuator.


  • Charge: fluid, wax, gas, adsorption charge, mixed phases, refrigerant
  • Expansion from 0.05 up to 0.6 mm/K
  • Applicable for temperatures from -35°C up to +380°C
  • Linear characteristic 
  • Low hysteresis
  • Pressure or displacement limitation (only gas, refrigerant and mixed phases charges)


Copper, bronze (only bellow), brass or stainless steel, various layers on request.

Testing, Tests, Simulation
System-oriented testing.
All of the EGELHOF products are tested in our state of the art simulation and test benches during product design.
These test installations are also offered as an external service.